1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243
|
/*
* Copyright © 2015 Red Hat, Inc
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*
* Authors:
* Alexander Larsson <alexl@redhat.com>
*/
#include "config.h"
#include <unistd.h>
#include <string.h>
#include "flatpak-proxy.h"
#include <gio/gunixsocketaddress.h>
#include <gio/gunixconnection.h>
#include <gio/gunixfdmessage.h>
#if !GLIB_CHECK_VERSION(2, 58, 0)
# define G_SOURCE_FUNC(f) ((GSourceFunc) (void (*)(void)) (f))
#endif
/**
* The proxy listens to a unix domain socket, and for each new
* connection it opens up a new connection to a specified dbus bus
* address (typically the session bus) and forwards data between the
* two. During the authentication phase all data is forwarded as
* received, and additionally for the first 1 byte zero we also send
* the proxy credentials to the bus.
*
* Once the connection is authenticated there are two modes, filtered
* and unfiltered. In the unfiltered mode we just send all messages on
* as we receive, but in the in the filtering mode we apply a policy,
* which is similar to the policy supported by kdbus.
*
* The policy for the filtering consists of a mapping from well-known
* names to a policy that is either SEE, TALK or OWN. The default
* initial policy is that the the user is only allowed to TALK to the
* bus itself (org.freedesktop.DBus, or no destination specified), and
* TALK to its own unique id. All other clients are invisible. The
* well-known names can be specified exactly, or as a arg0namespace
* wildcards like "org.foo.*" which matches "org.foo", "org.foo.bar",
* and "org.foo.bar.gazonk", but not "org.foobar".
*
* Polices are specified for well-known names, but they also affect
* the owner of that name, so that the policy for a unique id is the
* superset of the polices for all the names it owns. Due to technical
* reasons the policy for a unique name is "sticky", in that we keep
* the highest policy granted by a once-owned name even when the client
* releases that name. This is impossible to avoid in a race-free way
* in a proxy. But this is rarely a problem in practice, as clients
* rarely release names and stay on the bus.
*
* Here is a description of the policy levels:
* (all policy levels also imply the ones before it)
*
* SEE:
* The name/id is visible in the ListNames reply
* The name/id is visible in the ListActivatableNames reply
* You can call GetNameOwner on the name
* You can call NameHasOwner on the name
* You see NameOwnerChanged signals on the name
* You see NameOwnerChanged signals on the id when the client disconnects
* You can call the GetXXX methods on the name/id to get e.g. the peer pid
* You get AccessDenied rather than NameHasNoOwner when sending messages to the name/id
*
* TALK:
* You can send any method calls and signals to the name/id
* You will receive broadcast signals from the name/id (if you have a match rule for them)
* You can call StartServiceByName on the name
*
* OWN:
* You are allowed to call RequestName/ReleaseName/ListQueuedOwners on the name.
*
* Additionally, there can be more detailed filters installed that
* limits what messages you can send to and receive broadcasts from.
* However, if you can *ever* call or recieve broadcasts from a name (even if
* filtered to some subset of paths/interfaces) its visibility is considered
* to be as TALK.
*
* The policy applies only to outgoing signals and method calls and
* incoming broadcast. All replies (errors or method returns) are
* allowed once for an outstanding method call, and never
* otherwise.
*
* Every peer on the bus is considered priviledged, and we thus trust
* it and don't apply any filtering (except broadcasts). So we rely on
* similar proxies to be running for all untrusted clients. Any such
* priviledged peer is allowed to send method call or unicast signal
* messages to the proxied client. Once another peer
* sends you a message the unique id of that peer is now made visible
* (policy SEE) to the proxied client, allowing the client to track
* caller lifetimes via NameOwnerChanged signals.
*
* Differences to kdbus custom endpoint policies:
*
* * The proxy will return the credentials (like pid) of the proxy,
* not the real client.
*
* * Policy is not dropped when a peer releases a name.
*
* * Peers that call you become visible (SEE) (and get signals for
* NameOwnerChange disconnect) In kdbus currently custom endpoints
* never get NameOwnerChange signals for unique ids, but this is
* problematic as it disallows a services to track lifetimes of its
* clients.
*
* Mode of operation
*
* Once authenticated we receive incoming messages one at a time,
* and then we demarshal the message headers to make routing decisions.
* This means we trust the bus to do message format validation, etc.
* (because we don't parse the body). Also we assume that the bus verifies
* reply_serials, i.e. that a reply can only be sent once and by the real
* recipient of an previously sent method call.
*
* Serial numbers larger than MAX_CLIENT_SERIAL reserved for messages created by the
* proxy itself (fake messages). This limits the possible values of serials
* available to the client to the value of MAX_CLIENT_SERIAL. Versions
* older than 0.1.6 required monotonically increasing serials instead. This
* mechanism was dropped since it caused regular issues with multiple D-Bus
* clients.
*
* In order to track the ownership of the allowed names we hijack the
* connection after the initial Hello message, sending AddMatch,
* ListNames and GetNameOwner messages to get a proper view of who
* owns the names atm. Then we listen to NameOwnerChanged events for
* further updates. This causes some serials abow MAX_CLIENT_SERIAL to be
* used for "fake messages".
*
* After that the filter is strictly passive, in that we never
* construct our own requests. For each message received from the
* client we look up the type and the destination policy and make a
* decision to either pass it on as is, rewrite it before passing on
* (for instance ListName replies), drop it completely, or return a
* made-up reply/error to the sender.
*
* When returning a made-up reply we replace the actual message with a
* Ping request to the bus with the same serial and replace the resulting
* reply with the made up reply (with the serial from the Ping reply).
* This means we keep the strict message ordering and serial numbers of
* the bus.
*
* Policy is applied to unique ids in the following cases:
* * During startup we call AddWatch for signals on all policy names
* and wildcards (using arg0namespace) so that we get NameOwnerChanged
* events which we use to update the unique id policies.
* * During startup we create synthetic GetNameOwner requests for all
* normal policy names, and if there are wildcarded names we create a
* synthetic ListNames request and use the results of that to do further
* GetNameOwner for the existing names matching the wildcards. When we get
* replies for the GetNameOwner requests the unique id policy is updated.
* * When we get a method call from a unique id, it gets SEE
* * When we get a reply to the initial Hello request we give
* our own assigned unique id policy TALK.
*
* There is also a mode called "sloppy-names" where you automatically get
* SEE access to all the unique names on the bus. This is used only for
* the a11y bus.
*
* All messages sent to the bus itself are fully demarshalled
* and handled on a per-method basis:
*
* Hello, AddMatch, RemoveMatch, GetId: Always allowed
* ListNames, ListActivatableNames: Always allowed, but response filtered
* UpdateActivationEnvironment, BecomeMonitor: Always denied
* RequestName, ReleaseName, ListQueuedOwners: Only allowed if arg0 is a name with policy OWN
* NameHasOwner, GetNameOwner: Only pass on if arg0 is a name with policy SEE, otherwise return synthetic reply
* StartServiceByName: Only allowed if policy TALK on arg0
* GetConnectionUnixProcessID, GetConnectionCredentials,
* GetAdtAuditSessionData, GetConnectionSELinuxSecurityContext,
* GetConnectionUnixUser: Allowed if policy SEE on arg0
*
* For unknown methods, we return a synthetic error.
*/
typedef struct FlatpakProxyClient FlatpakProxyClient;
#define FIND_AUTH_END_CONTINUE -1
#define FIND_AUTH_END_ABORT -2
#define AUTH_LINE_SENTINEL "\r\n"
#define AUTH_BEGIN "BEGIN"
// Use a relatively hight number since there are not a lot of fake requests we need to do
#define MAX_CLIENT_SERIAL (G_MAXUINT32 - 65536)
typedef enum {
/* The client has not sent BEGIN yet */
AUTH_WAITING_FOR_BEGIN,
/* The client sent BEGIN, but the server has not yet responded to the auth
messages that the client sent before */
AUTH_WAITING_FOR_BACKLOG,
/* Authentication is fully complete */
AUTH_COMPLETE,
} AuthState;
typedef enum {
EXPECTED_REPLY_NONE,
EXPECTED_REPLY_NORMAL,
EXPECTED_REPLY_HELLO,
EXPECTED_REPLY_FILTER,
EXPECTED_REPLY_FAKE_GET_NAME_OWNER,
EXPECTED_REPLY_FAKE_LIST_NAMES,
EXPECTED_REPLY_LIST_NAMES,
EXPECTED_REPLY_REWRITE,
} ExpectedReplyType;
typedef struct
{
/* During write and message parsing this is the size of the valid data in the buffer.
During reads this is the capacity of the buffer. */
gsize size;
/* Offset to the first writable position (the buffer is full when pos ==
* size) */
gsize pos;
/* Offset to the first byte that hasn't been sent yet */
gsize sent;
int refcount;
gboolean send_credentials;
GList *control_messages;
guchar data[16];
/* data continues here */
} Buffer;
typedef struct
{
Buffer *buffer;
gboolean big_endian;
guchar type;
guchar flags;
guint32 length;
guint32 serial;
const char *path;
const char *interface;
const char *member;
const char *error_name;
const char *destination;
const char *sender;
const char *signature;
gboolean has_reply_serial;
guint32 reply_serial;
guint32 unix_fds;
} Header;
typedef enum {
FILTER_TYPE_CALL = 1 << 0,
FILTER_TYPE_BROADCAST = 1 << 1,
} FilterTypeMask;
#define FILTER_TYPE_ALL (FILTER_TYPE_CALL | FILTER_TYPE_BROADCAST)
typedef struct
{
char *name;
gboolean name_is_subtree;
FlatpakPolicy policy;
/* More detailed filter */
FilterTypeMask types;
char *path;
gboolean path_is_subtree;
char *interface;
char *member;
} Filter;
static void header_free (Header *header);
G_DEFINE_AUTOPTR_CLEANUP_FUNC (Header, header_free)
typedef struct
{
gboolean got_first_byte; /* always true on bus side */
gboolean closed; /* always true on bus side */
FlatpakProxyClient *client;
GSocketConnection *connection;
GSource *in_source;
GSource *out_source;
GBytes *extra_input_data;
Buffer *current_read_buffer;
Buffer header_buffer;
GList *buffers; /* to be sent */
GList *control_messages;
GHashTable *expected_replies;
} ProxySide;
struct FlatpakProxyClient
{
GObject parent;
FlatpakProxy *proxy;
AuthState auth_state;
gsize auth_requests;
gsize auth_replies;
GByteArray *auth_buffer;
ProxySide client_side;
ProxySide bus_side;
/* Filtering data: */
guint32 hello_serial;
guint32 last_fake_serial;
GHashTable *rewrite_reply;
GHashTable *get_owner_reply;
GHashTable *unique_id_policy;
GHashTable *unique_id_owned_names;
};
typedef struct
{
GObjectClass parent_class;
} FlatpakProxyClientClass;
struct FlatpakProxy
{
GSocketService parent;
gboolean log_messages;
GList *clients;
char *socket_path;
char *dbus_address;
gboolean filter;
gboolean sloppy_names;
GHashTable *filters;
};
typedef struct
{
GSocketServiceClass parent_class;
} FlatpakProxyClass;
enum {
PROP_0,
PROP_DBUS_ADDRESS,
PROP_SOCKET_PATH
};
#define FLATPAK_TYPE_PROXY flatpak_proxy_get_type ()
#define FLATPAK_PROXY(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), FLATPAK_TYPE_PROXY, FlatpakProxy))
#define FLATPAK_IS_PROXY(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), FLATPAK_TYPE_PROXY))
#define FLATPAK_TYPE_PROXY_CLIENT flatpak_proxy_client_get_type ()
#define FLATPAK_PROXY_CLIENT(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), FLATPAK_TYPE_PROXY_CLIENT, FlatpakProxyClient))
#define FLATPAK_IS_PROXY_CLIENT(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), FLATPAK_TYPE_PROXY_CLIENT))
GType flatpak_proxy_client_get_type (void);
G_DEFINE_TYPE (FlatpakProxy, flatpak_proxy, G_TYPE_SOCKET_SERVICE)
G_DEFINE_TYPE (FlatpakProxyClient, flatpak_proxy_client, G_TYPE_OBJECT)
static void start_reading (ProxySide *side);
static void stop_reading (ProxySide *side);
static void
string_list_free (GList *filters)
{
g_list_free_full (filters, (GDestroyNotify) g_free);
}
static void
buffer_unref (Buffer *buffer)
{
g_assert (buffer->refcount > 0);
buffer->refcount--;
if (buffer->refcount == 0)
{
g_list_free_full (buffer->control_messages, g_object_unref);
g_free (buffer);
}
}
static Buffer *
buffer_ref (Buffer *buffer)
{
g_assert (buffer->refcount > 0);
buffer->refcount++;
return buffer;
}
static void
free_side (ProxySide *side)
{
g_clear_object (&side->connection);
g_clear_pointer (&side->extra_input_data, g_bytes_unref);
g_list_free_full (side->buffers, (GDestroyNotify) buffer_unref);
g_list_free_full (side->control_messages, (GDestroyNotify) g_object_unref);
if (side->in_source)
g_source_destroy (side->in_source);
if (side->out_source)
g_source_destroy (side->out_source);
g_hash_table_destroy (side->expected_replies);
}
static void
flatpak_proxy_client_finalize (GObject *object)
{
FlatpakProxyClient *client = FLATPAK_PROXY_CLIENT (object);
client->proxy->clients = g_list_remove (client->proxy->clients, client);
g_clear_object (&client->proxy);
g_byte_array_free (client->auth_buffer, TRUE);
g_hash_table_destroy (client->rewrite_reply);
g_hash_table_destroy (client->get_owner_reply);
g_hash_table_destroy (client->unique_id_policy);
g_hash_table_destroy (client->unique_id_owned_names);
free_side (&client->client_side);
free_side (&client->bus_side);
G_OBJECT_CLASS (flatpak_proxy_client_parent_class)->finalize (object);
}
static void
flatpak_proxy_client_class_init (FlatpakProxyClientClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
object_class->finalize = flatpak_proxy_client_finalize;
}
static void
init_side (FlatpakProxyClient *client, ProxySide *side)
{
side->got_first_byte = (side == &client->bus_side);
side->client = client;
side->header_buffer.size = 16;
side->header_buffer.pos = 0;
side->current_read_buffer = &side->header_buffer;
side->expected_replies = g_hash_table_new (g_direct_hash, g_direct_equal);
}
static void
flatpak_proxy_client_init (FlatpakProxyClient *client)
{
init_side (client, &client->client_side);
init_side (client, &client->bus_side);
client->last_fake_serial = MAX_CLIENT_SERIAL;
client->auth_buffer = g_byte_array_new ();
client->rewrite_reply = g_hash_table_new_full (g_direct_hash, g_direct_equal, NULL, g_object_unref);
client->get_owner_reply = g_hash_table_new_full (g_direct_hash, g_direct_equal, NULL, g_free);
client->unique_id_policy = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
client->unique_id_owned_names = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, (GDestroyNotify) string_list_free);
}
static FlatpakProxyClient *
flatpak_proxy_client_new (FlatpakProxy *proxy, GSocketConnection *connection)
{
FlatpakProxyClient *client;
g_socket_set_blocking (g_socket_connection_get_socket (connection), FALSE);
client = g_object_new (FLATPAK_TYPE_PROXY_CLIENT, NULL);
client->proxy = g_object_ref (proxy);
client->client_side.connection = g_object_ref (connection);
proxy->clients = g_list_prepend (proxy->clients, client);
return client;
}
void
flatpak_proxy_set_filter (FlatpakProxy *proxy,
gboolean filter)
{
proxy->filter = filter;
}
void
flatpak_proxy_set_sloppy_names (FlatpakProxy *proxy,
gboolean sloppy_names)
{
proxy->sloppy_names = sloppy_names;
}
void
flatpak_proxy_set_log_messages (FlatpakProxy *proxy,
gboolean log)
{
proxy->log_messages = log;
}
static void
filter_free (Filter *filter)
{
g_free (filter->name);
g_free (filter->path);
g_free (filter->interface);
g_free (filter->member);
g_free (filter);
}
static void
filter_list_free (GList *filters)
{
g_list_free_full (filters, (GDestroyNotify) filter_free);
}
static Filter *
filter_new (const char *name,
gboolean name_is_subtree,
FlatpakPolicy policy)
{
Filter *filter = g_new0 (Filter, 1);
filter->name = g_strdup (name);
filter->name_is_subtree = name_is_subtree;
filter->policy = policy;
filter->types = FILTER_TYPE_ALL;
return filter;
}
// rules are of the form [*|org.the.interface.[method|*]]|[@/obj/path[/*]]
static Filter *
filter_new_from_rule (const char *name,
gboolean name_is_subtree,
FilterTypeMask types,
const char *rule)
{
Filter *filter;
const char *obj_path_start = NULL;
const char *method_end = NULL;
filter = filter_new (name, name_is_subtree, FLATPAK_POLICY_TALK);
filter->types = types;
obj_path_start = strchr (rule, '@');
if (obj_path_start && obj_path_start[1] != 0)
{
filter->path = g_strdup (obj_path_start + 1);
if (g_str_has_suffix (filter->path, "/*"))
{
filter->path_is_subtree = TRUE;
filter->path[strlen (filter->path) - 2] = 0;
}
}
if (obj_path_start != NULL)
method_end = obj_path_start;
else
method_end = rule + strlen (rule);
if (method_end != rule)
{
if (rule[0] == '*')
{
/* Both interface and method wildcarded */
}
else
{
filter->interface = g_strndup (rule, method_end - rule);
char *dot = strrchr (filter->interface, '.');
if (dot != NULL)
{
*dot = 0;
if (strcmp (dot + 1, "*") != 0)
filter->member = g_strdup (dot + 1);
}
}
}
return filter;
}
static gboolean
filter_matches (Filter *filter,
FilterTypeMask type,
const char *path,
const char *interface,
const char *member)
{
if (filter->policy < FLATPAK_POLICY_TALK ||
(filter->types & type) == 0)
return FALSE;
if (filter->path)
{
if (path == NULL)
return FALSE;
if (filter->path_is_subtree)
{
gsize filter_path_len = strlen (filter->path);
if (strncmp (path, filter->path, filter_path_len) != 0 ||
(path[filter_path_len] != 0 && path[filter_path_len] != '/'))
return FALSE;
}
else if (strcmp (filter->path, path) != 0)
return FALSE;
}
if (filter->interface && g_strcmp0 (filter->interface, interface) != 0)
return FALSE;
if (filter->member && g_strcmp0 (filter->member, member) != 0)
return FALSE;
return TRUE;
}
static gboolean
any_filter_matches (GList *filters,
FilterTypeMask type,
const char *path,
const char *interface,
const char *member)
{
GList *l;
for (l = filters; l != NULL; l = l->next)
{
Filter *filter = l->data;
if (filter_matches (filter, type, path, interface, member))
return TRUE;
}
return FALSE;
}
static void
flatpak_proxy_add_filter (FlatpakProxy *proxy,
Filter *filter)
{
GList *filters, *new_filters;
if (g_hash_table_lookup_extended (proxy->filters,
filter->name,
NULL, (void **) &filters))
{
new_filters = g_list_append (filters, filter);
g_assert (new_filters == filters);
}
else
{
filters = g_list_append (NULL, filter);
g_hash_table_insert (proxy->filters, g_strdup (filter->name), filters);
}
}
void
flatpak_proxy_add_policy (FlatpakProxy *proxy,
const char *name,
gboolean name_is_subtree,
FlatpakPolicy policy)
{
Filter *filter = filter_new (name, name_is_subtree, policy);
flatpak_proxy_add_filter (proxy, filter);
}
void
flatpak_proxy_add_call_rule (FlatpakProxy *proxy,
const char *name,
gboolean name_is_subtree,
const char *rule)
{
Filter *filter = filter_new_from_rule (name, name_is_subtree, FILTER_TYPE_CALL, rule);
flatpak_proxy_add_filter (proxy, filter);
}
void
flatpak_proxy_add_broadcast_rule (FlatpakProxy *proxy,
const char *name,
gboolean name_is_subtree,
const char *rule)
{
Filter *filter = filter_new_from_rule (name, name_is_subtree, FILTER_TYPE_BROADCAST, rule);
flatpak_proxy_add_filter (proxy, filter);
}
static void
flatpak_proxy_finalize (GObject *object)
{
FlatpakProxy *proxy = FLATPAK_PROXY (object);
if (g_socket_service_is_active (G_SOCKET_SERVICE (proxy)))
unlink (proxy->socket_path);
g_assert (proxy->clients == NULL);
g_hash_table_destroy (proxy->filters);
g_free (proxy->socket_path);
g_free (proxy->dbus_address);
G_OBJECT_CLASS (flatpak_proxy_parent_class)->finalize (object);
}
static void
flatpak_proxy_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
FlatpakProxy *proxy = FLATPAK_PROXY (object);
switch (prop_id)
{
case PROP_DBUS_ADDRESS:
proxy->dbus_address = g_value_dup_string (value);
break;
case PROP_SOCKET_PATH:
proxy->socket_path = g_value_dup_string (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
flatpak_proxy_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
FlatpakProxy *proxy = FLATPAK_PROXY (object);
switch (prop_id)
{
case PROP_DBUS_ADDRESS:
g_value_set_string (value, proxy->dbus_address);
break;
case PROP_SOCKET_PATH:
g_value_set_string (value, proxy->socket_path);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
/* Buffer contains a default size of data that is 16 bytes, so that
it can be used on the stack for reading the header. However we
also support passing in sizes smaller that 16, which will allocate
a smaller object than the full Buffer object. This is safe as we
respect the size member, however there is no way for GCC to know this,
so we silence it manually.
*/
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Warray-bounds"
static Buffer *
buffer_new (gsize size, Buffer *old)
{
Buffer *buffer = g_malloc0 (sizeof (Buffer) + size - 16);
buffer->control_messages = NULL;
buffer->size = size;
buffer->refcount = 1;
if (old)
{
buffer->pos = old->pos;
buffer->sent = old->sent;
/* Takes ownership of any old control messages */
buffer->control_messages = old->control_messages;
old->control_messages = NULL;
g_assert (size >= old->size);
memcpy (buffer->data, old->data, old->size);
}
return buffer;
}
#pragma GCC diagnostic pop
static ProxySide *
get_other_side (ProxySide *side)
{
FlatpakProxyClient *client = side->client;
if (side == &client->client_side)
return &client->bus_side;
return &client->client_side;
}
static void
side_closed (ProxySide *side)
{
GSocket *socket, *other_socket;
ProxySide *other_side = get_other_side (side);
if (side->closed)
return;
socket = g_socket_connection_get_socket (side->connection);
g_socket_close (socket, NULL);
side->closed = TRUE;
other_socket = g_socket_connection_get_socket (other_side->connection);
if (!other_side->closed && other_side->buffers == NULL)
{
g_socket_close (other_socket, NULL);
other_side->closed = TRUE;
}
if (other_side->closed)
{
g_object_unref (side->client);
}
else
{
GError *error = NULL;
if (!g_socket_shutdown (other_socket, TRUE, FALSE, &error))
{
g_warning ("Unable to shutdown read side: %s", error->message);
g_error_free (error);
}
}
}
static gboolean
buffer_read (ProxySide *side,
Buffer *buffer,
GSocket *socket)
{
FlatpakProxyClient *client = side->client;
gsize received = 0;
GInputVector v;
GError *error = NULL;
GSocketControlMessage **messages;
int num_messages, i;
if (client->auth_state == AUTH_WAITING_FOR_BACKLOG &&
side == &client->client_side)
return FALSE;
if (side->extra_input_data && client->auth_state == AUTH_COMPLETE)
{
gsize extra_size;
const guchar *extra_bytes = g_bytes_get_data (side->extra_input_data, &extra_size);
g_assert (buffer->size >= buffer->pos);
received = MIN (extra_size, buffer->size - buffer->pos);
memcpy (&buffer->data[buffer->pos], extra_bytes, received);
if (received < extra_size)
{
side->extra_input_data =
g_bytes_new_with_free_func (extra_bytes + received,
extra_size - received,
(GDestroyNotify) g_bytes_unref,
side->extra_input_data);
}
else
{
g_clear_pointer (&side->extra_input_data, g_bytes_unref);
}
}
else if (!side->extra_input_data)
{
gssize res;
int flags = 0;
v.buffer = &buffer->data[buffer->pos];
v.size = buffer->size - buffer->pos;
res = g_socket_receive_message (socket, NULL, &v, 1,
&messages,
&num_messages,
&flags, NULL, &error);
if (res < 0 && g_error_matches (error, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK))
{
g_error_free (error);
return FALSE;
}
if (res <= 0)
{
if (res != 0)
{
g_debug ("Error reading from socket: %s", error->message);
g_error_free (error);
}
side_closed (side);
return FALSE;
}
/* We now know res is strictly positive */
received = (gsize) res;
for (i = 0; i < num_messages; i++)
buffer->control_messages = g_list_append (buffer->control_messages, messages[i]);
g_free (messages);
}
buffer->pos += received;
return TRUE;
}
static gboolean
buffer_write (ProxySide *side,
Buffer *buffer,
GSocket *socket)
{
gssize res;
GOutputVector v;
GError *error = NULL;
GSocketControlMessage **messages = NULL;
int i, n_messages;
GList *l;
if (buffer->send_credentials &&
G_IS_UNIX_CONNECTION (side->connection))
{
g_assert (buffer->size == 1);
if (!g_unix_connection_send_credentials (G_UNIX_CONNECTION (side->connection),
NULL,
&error))
{
if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK))
{
g_error_free (error);
return FALSE;
}
g_warning ("Error writing credentials to socket: %s", error->message);
g_error_free (error);
side_closed (side);
return FALSE;
}
buffer->sent = 1;
return TRUE;
}
n_messages = g_list_length (buffer->control_messages);
messages = g_new (GSocketControlMessage *, n_messages);
for (l = buffer->control_messages, i = 0; l != NULL; l = l->next, i++)
messages[i] = l->data;
v.buffer = &buffer->data[buffer->sent];
v.size = buffer->pos - buffer->sent;
res = g_socket_send_message (socket, NULL, &v, 1,
messages, n_messages,
G_SOCKET_MSG_NONE, NULL, &error);
g_free (messages);
if (res < 0 && g_error_matches (error, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK))
{
g_error_free (error);
return FALSE;
}
if (res <= 0)
{
if (res < 0)
{
g_warning ("Error writing credentials to socket: %s", error->message);
g_error_free (error);
}
side_closed (side);
return FALSE;
}
g_list_free_full (buffer->control_messages, g_object_unref);
buffer->control_messages = NULL;
buffer->sent += res;
return TRUE;
}
static gboolean
send_outgoing_buffers (GSocket *socket, ProxySide *side)
{
FlatpakProxyClient *client = side->client;
gboolean all_done = FALSE;
g_object_ref (client);
while (side->buffers)
{
Buffer *buffer = side->buffers->data;
if (buffer_write (side, buffer, socket))
{
if (buffer->sent == buffer->size)
{
side->buffers = g_list_delete_link (side->buffers, side->buffers);
buffer_unref (buffer);
}
}
else
{
break;
}
}
if (side->buffers == NULL)
{
ProxySide *other_side = get_other_side (side);
all_done = TRUE;
if (other_side->closed)
side_closed (side);
}
g_object_unref (client);
return all_done;
}
static gboolean
side_out_cb (GSocket *socket, GIOCondition condition, gpointer user_data)
{
ProxySide *side = user_data;
gboolean all_done = send_outgoing_buffers (socket, side);
if (all_done)
{
side->out_source = NULL;
return G_SOURCE_REMOVE;
}
else
{
return G_SOURCE_CONTINUE;
}
}
static void
queue_expected_reply (ProxySide *side, guint32 serial, ExpectedReplyType type)
{
g_hash_table_replace (side->expected_replies,
GUINT_TO_POINTER (serial),
GUINT_TO_POINTER (type));
}
static ExpectedReplyType
steal_expected_reply (ProxySide *side, guint32 serial)
{
ExpectedReplyType type;
type = GPOINTER_TO_UINT (g_hash_table_lookup (side->expected_replies,
GUINT_TO_POINTER (serial)));
if (type)
g_hash_table_remove (side->expected_replies,
GUINT_TO_POINTER (serial));
return type;
}
static void
queue_outgoing_buffer (ProxySide *side, Buffer *buffer)
{
if (side->out_source == NULL)
{
GSocket *socket;
socket = g_socket_connection_get_socket (side->connection);
side->out_source = g_socket_create_source (socket, G_IO_OUT, NULL);
g_source_set_callback (side->out_source, G_SOURCE_FUNC (side_out_cb), side, NULL);
g_source_attach (side->out_source, NULL);
g_source_unref (side->out_source);
}
side->buffers = g_list_append (side->buffers, buffer);
}
static guint32
read_uint32 (Header *header, guint8 *ptr)
{
if (header->big_endian)
return GUINT32_FROM_BE (*(guint32 *) ptr);
else
return GUINT32_FROM_LE (*(guint32 *) ptr);
}
static inline guint32
align_by_8 (guint32 offset)
{
return (offset + 8 - 1) & ~(8 - 1);
}
static inline guint32
align_by_4 (guint32 offset)
{
return (offset + 4 - 1) & ~(4 - 1);
}
static const char *
get_signature (Buffer *buffer, guint32 *offset, guint32 end_offset)
{
guint8 len;
char *str;
if (*offset >= end_offset)
return FALSE;
len = buffer->data[*offset];
(*offset)++;
if ((*offset) + len + 1 > end_offset)
return FALSE;
if (buffer->data[(*offset) + len] != 0)
return FALSE;
str = (char *) &buffer->data[(*offset)];
*offset += len + 1;
return str;
}
static const char *
get_string (Buffer *buffer, Header *header, guint32 *offset, guint32 end_offset, GError **error)
{
guint32 len;
char *str;
*offset = align_by_4 (*offset);
if (*offset + 4 >= end_offset)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"String header would align past boundary");
return FALSE;
}
len = read_uint32 (header, &buffer->data[*offset]);
*offset += 4;
if ((*offset) + len + 1 > end_offset)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"String would align past boundary");
return FALSE;
}
if (buffer->data[(*offset) + len] != 0)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"String is not nul-terminated (%.*s)",
buffer->data[(*offset) + len],
(char *) &buffer->data[(*offset)]);
return FALSE;
}
str = (char *) &buffer->data[(*offset)];
*offset += len + 1;
return str;
}
static void
header_free (Header *header)
{
if (header->buffer)
buffer_unref (header->buffer);
g_free (header);
}
static const char *
header_debug_str (GString *s, Header *header)
{
if (header->path)
g_string_append_printf (s, "\n\tPath: %s", header->path);
if (header->interface)
g_string_append_printf (s, "\n\tInterface: %s", header->interface);
if (header->member)
g_string_append_printf (s, "\n\tMember: %s", header->member);
if (header->error_name)
g_string_append_printf (s, "\n\tError name: %s", header->error_name);
if (header->destination)
g_string_append_printf (s, "\n\tDestination: %s", header->destination);
if (header->sender)
g_string_append_printf (s, "\n\tSender: %s", header->sender);
return s->str;
}
static Header *
parse_header (Buffer *buffer, GError **error)
{
guint32 array_len, header_len;
guint32 offset, end_offset;
guint8 header_type;
const char *signature;
g_autoptr(GError) str_error = NULL;
g_autoptr(GString) header_str = NULL;
g_autoptr(Header) header = g_new0 (Header, 1);
header->buffer = buffer_ref (buffer);
if (buffer->size < 16)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Buffer too small: %"G_GSIZE_FORMAT, buffer->size);
return NULL;
}
if (buffer->data[3] != 1) /* Protocol version */
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Wrong protocol version: %d", buffer->data[3]);
return NULL;
}
if (buffer->data[0] == 'B')
header->big_endian = TRUE;
else if (buffer->data[0] == 'l')
header->big_endian = FALSE;
else
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Invalid endianess marker: %c", buffer->data[0]);
return NULL;
}
header->type = buffer->data[1];
header->flags = buffer->data[2];
header->length = read_uint32 (header, &buffer->data[4]);
header->serial = read_uint32 (header, &buffer->data[8]);
if (header->serial == 0)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"No serial");
return NULL;
}
array_len = read_uint32 (header, &buffer->data[12]);
header_len = align_by_8 (12 + 4 + array_len);
g_assert (buffer->size >= header_len); /* We should have verified this when reading in the message */
if (header_len > buffer->size)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Header len (%d) bigger than buffer size (%"G_GSIZE_FORMAT")",
header_len, buffer->size);
return NULL;
}
offset = 12 + 4;
end_offset = offset + array_len;
header_str = g_string_new (NULL);
while (offset < end_offset)
{
offset = align_by_8 (offset); /* Structs must be 8 byte aligned */
if (offset >= end_offset)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Struct would align past boundary%s",
header_debug_str (header_str, header));
return NULL;
}
header_type = buffer->data[offset++];
if (offset >= end_offset)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Went past boundary after parsing header_type%s",
header_debug_str (header_str, header));
return NULL;
}
signature = get_signature (buffer, &offset, end_offset);
if (signature == NULL)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Could not parse signature%s",
header_debug_str (header_str, header));
return NULL;
}
switch (header_type)
{
case G_DBUS_MESSAGE_HEADER_FIELD_INVALID:
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Field is invalid%s",
header_debug_str (header_str, header));
return NULL;
case G_DBUS_MESSAGE_HEADER_FIELD_PATH:
if (strcmp (signature, "o") != 0)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Signature is invalid for path ('%s')%s",
signature,
header_debug_str (header_str, header));
return NULL;
}
header->path = get_string (buffer, header, &offset, end_offset, &str_error);
if (header->path == NULL)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Could not parse path in path field: %s%s",
str_error->message,
header_debug_str (header_str, header));
return NULL;
}
break;
case G_DBUS_MESSAGE_HEADER_FIELD_INTERFACE:
if (strcmp (signature, "s") != 0)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Signature is invalid for interface ('%s')%s",
signature,
header_debug_str (header_str, header));
return NULL;
}
header->interface = get_string (buffer, header, &offset, end_offset, &str_error);
if (header->interface == NULL)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Could not parse interface in interface field: %s%s",
str_error->message,
header_debug_str (header_str, header));
return NULL;
}
break;
case G_DBUS_MESSAGE_HEADER_FIELD_MEMBER:
if (strcmp (signature, "s") != 0)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Signature is invalid for member ('%s')%s",
signature,
header_debug_str (header_str, header));
return NULL;
}
header->member = get_string (buffer, header, &offset, end_offset, &str_error);
if (header->member == NULL)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Could not parse member in member field: %s%s",
str_error->message,
header_debug_str (header_str, header));
return NULL;
}
break;
case G_DBUS_MESSAGE_HEADER_FIELD_ERROR_NAME:
if (strcmp (signature, "s") != 0)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Signature is invalid for error ('%s')%s",
signature,
header_debug_str (header_str, header));
return NULL;
}
header->error_name = get_string (buffer, header, &offset, end_offset, &str_error);
if (header->error_name == NULL)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Could not parse error in error field: %s%s",
str_error->message,
header_debug_str (header_str, header));
return NULL;
}
break;
case G_DBUS_MESSAGE_HEADER_FIELD_REPLY_SERIAL:
if (offset + 4 > end_offset)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Header too small to fit reply serial%s",
header_debug_str (header_str, header));
return NULL;
}
header->has_reply_serial = TRUE;
header->reply_serial = read_uint32 (header, &buffer->data[offset]);
offset += 4;
break;
case G_DBUS_MESSAGE_HEADER_FIELD_DESTINATION:
if (strcmp (signature, "s") != 0)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Signature is invalid for destination ('%s')%s",
signature,
header_debug_str (header_str, header));
return NULL;
}
header->destination = get_string (buffer, header, &offset, end_offset, &str_error);
if (header->destination == NULL)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Could not parse destination in destination field: %s%s",
str_error->message,
header_debug_str (header_str, header));
return NULL;
}
break;
case G_DBUS_MESSAGE_HEADER_FIELD_SENDER:
if (strcmp (signature, "s") != 0)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Signature is invalid for sender ('%s')%s",
signature,
header_debug_str (header_str, header));
return NULL;
}
header->sender = get_string (buffer, header, &offset, end_offset, &str_error);
if (header->sender == NULL)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Could not parse sender in sender field: %s%s",
str_error->message,
header_debug_str (header_str, header));
return NULL;
}
break;
case G_DBUS_MESSAGE_HEADER_FIELD_SIGNATURE:
if (strcmp (signature, "g") != 0)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Signature is invalid for signature ('%s')%s",
signature,
header_debug_str (header_str, header));
return NULL;
}
header->signature = get_signature (buffer, &offset, end_offset);
if (header->signature == NULL)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Could not parse signature in signature field%s",
header_debug_str (header_str, header));
return NULL;
}
break;
case G_DBUS_MESSAGE_HEADER_FIELD_NUM_UNIX_FDS:
if (offset + 4 > end_offset)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Header too small to fit Unix FDs%s",
header_debug_str (header_str, header));
return NULL;
}
header->unix_fds = read_uint32 (header, &buffer->data[offset]);
offset += 4;
break;
default:
/* Unknown header field, for safety, fail parse */
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Unknown header field (%d)%s",
header_type,
header_debug_str (header_str, header));
return NULL;
}
}
switch (header->type)
{
case G_DBUS_MESSAGE_TYPE_METHOD_CALL:
if (header->path == NULL || header->member == NULL)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Method call is missing path or member%s",
header_debug_str (header_str, header));
return NULL;
}
break;
case G_DBUS_MESSAGE_TYPE_METHOD_RETURN:
if (!header->has_reply_serial)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Method return has no reply serial%s",
header_debug_str (header_str, header));
return NULL;
}
break;
case G_DBUS_MESSAGE_TYPE_ERROR:
if (header->error_name == NULL || !header->has_reply_serial)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Error is missing error name or reply serial%s",
header_debug_str (header_str, header));
return NULL;
}
break;
case G_DBUS_MESSAGE_TYPE_SIGNAL:
if (header->path == NULL ||
header->interface == NULL ||
header->member == NULL)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Signal is missing path, interface or member%s",
header_debug_str (header_str, header));
return NULL;
}
if (strcmp (header->path, "/org/freedesktop/DBus/Local") == 0 ||
strcmp (header->interface, "org.freedesktop.DBus.Local") == 0)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Signal is to D-Bus Local path or interface%s",
header_debug_str (header_str, header));
return NULL;
}
break;
default:
/* Unknown message type, for safety, fail parse */
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
"Unknown message type (%d)%s",
header->type,
header_debug_str (header_str, header));
return NULL;
}
return g_steal_pointer (&header);
}
static void
print_outgoing_header (Header *header)
{
switch (header->type)
{
case G_DBUS_MESSAGE_TYPE_METHOD_CALL:
g_print ("C%d: -> %s call %s.%s at %s\n",
header->serial,
header->destination ? header->destination : "(no dest)",
header->interface ? header->interface : "",
header->member ? header->member : "",
header->path ? header->path : "");
break;
case G_DBUS_MESSAGE_TYPE_METHOD_RETURN:
g_print ("C%d: -> %s return from B%d\n",
header->serial,
header->destination ? header->destination : "(no dest)",
header->reply_serial);
break;
case G_DBUS_MESSAGE_TYPE_ERROR:
g_print ("C%d: -> %s return error %s from B%d\n",
header->serial,
header->destination ? header->destination : "(no dest)",
header->error_name ? header->error_name : "(no error)",
header->reply_serial);
break;
case G_DBUS_MESSAGE_TYPE_SIGNAL:
g_print ("C%d: -> %s signal %s.%s at %s\n",
header->serial,
header->destination ? header->destination : "all",
header->interface ? header->interface : "",
header->member ? header->member : "",
header->path ? header->path : "");
break;
default:
g_print ("unknown message type\n");
}
}
static void
print_incoming_header (Header *header)
{
switch (header->type)
{
case G_DBUS_MESSAGE_TYPE_METHOD_CALL:
g_print ("B%d: <- %s call %s.%s at %s\n",
header->serial,
header->sender ? header->sender : "(no sender)",
header->interface ? header->interface : "",
header->member ? header->member : "",
header->path ? header->path : "");
break;
case G_DBUS_MESSAGE_TYPE_METHOD_RETURN:
g_print ("B%d: <- %s return from C%d\n",
header->serial,
header->sender ? header->sender : "(no sender)",
header->reply_serial);
break;
case G_DBUS_MESSAGE_TYPE_ERROR:
g_print ("B%d: <- %s return error %s from C%d\n",
header->serial,
header->sender ? header->sender : "(no sender)",
header->error_name ? header->error_name : "(no error)",
header->reply_serial);
break;
case G_DBUS_MESSAGE_TYPE_SIGNAL:
g_print ("B%d: <- %s signal %s.%s at %s\n",
header->serial,
header->sender ? header->sender : "(no sender)",
header->interface ? header->interface : "",
header->member ? header->member : "",
header->path ? header->path : "");
break;
default:
g_print ("unknown message type\n");
}
}
static Filter *match_all[FLATPAK_POLICY_OWN + 1] = { NULL };
static FlatpakPolicy
flatpak_proxy_client_get_max_policy_and_matched (FlatpakProxyClient *client,
const char *source,
GList **matched_filters)
{
GList *names, *filters, *l;
FlatpakPolicy max_policy = FLATPAK_POLICY_NONE;
g_autofree char *name = NULL;
gboolean exact_name_match;
char *dot;
if (match_all[FLATPAK_POLICY_SEE] == NULL)
{
match_all[FLATPAK_POLICY_SEE] = filter_new ("", FALSE, FLATPAK_POLICY_SEE);
match_all[FLATPAK_POLICY_TALK] = filter_new ("", FALSE, FLATPAK_POLICY_TALK);
match_all[FLATPAK_POLICY_OWN] = filter_new ("", FALSE, FLATPAK_POLICY_OWN);
}
if (source == NULL)
{
if (matched_filters)
*matched_filters = g_list_append (*matched_filters, match_all[FLATPAK_POLICY_TALK]);
return FLATPAK_POLICY_TALK; /* All clients can talk to the bus itself */
}
if (source[0] == ':')
{
/* Default to the unique id policy, i.e. TALK for self, and SEE for trusted peers */
max_policy = GPOINTER_TO_UINT (g_hash_table_lookup (client->unique_id_policy, source));
if (max_policy > FLATPAK_POLICY_NONE && matched_filters)
*matched_filters = g_list_append (*matched_filters, match_all[max_policy]);
/* Treat this as the merged list of filters for all the names the unique id ever owned */
names = g_hash_table_lookup (client->unique_id_owned_names, source);
for (l = names; l != NULL; l = l->next)
{
const char *owned_name = l->data;
max_policy = MAX (max_policy, flatpak_proxy_client_get_max_policy_and_matched (client, owned_name, matched_filters));
}
return max_policy;
}
name = g_strdup (source);
exact_name_match = TRUE;
do
{
filters = g_hash_table_lookup (client->proxy->filters, name);
for (l = filters; l != NULL; l = l->next)
{
Filter *filter = l->data;
if (exact_name_match || filter->name_is_subtree)
{
max_policy = MAX (max_policy, filter->policy);
if (matched_filters)
*matched_filters = g_list_append (*matched_filters, filter);
}
}
exact_name_match = FALSE;
dot = strrchr (name, '.');
if (dot != NULL)
*dot = 0;
}
while (dot != NULL);
return max_policy;
}
static FlatpakPolicy
flatpak_proxy_client_get_max_policy (FlatpakProxyClient *client,
const char *source)
{
return flatpak_proxy_client_get_max_policy_and_matched (client, source, NULL);
}
static void
flatpak_proxy_client_update_unique_id_policy (FlatpakProxyClient *client,
const char *unique_id,
FlatpakPolicy policy)
{
if (policy > FLATPAK_POLICY_NONE)
{
FlatpakPolicy old_policy;
old_policy = GPOINTER_TO_UINT (g_hash_table_lookup (client->unique_id_policy, unique_id));
if (policy > old_policy)
g_hash_table_replace (client->unique_id_policy, g_strdup (unique_id), GINT_TO_POINTER (policy));
}
}
static void
flatpak_proxy_client_add_unique_id_owned_name (FlatpakProxyClient *client,
const char *unique_id,
const char *owned_name)
{
GList *names;
gboolean already_added;
names = NULL;
already_added = g_hash_table_lookup_extended (client->unique_id_owned_names,
unique_id,
NULL, (void **) &names);
names = g_list_append (names, g_strdup (owned_name));
if (!already_added)
g_hash_table_insert (client->unique_id_owned_names, g_strdup (unique_id), names);
}
static gboolean
client_message_generates_reply (Header *header)
{
switch (header->type)
{
case G_DBUS_MESSAGE_TYPE_METHOD_CALL:
return (header->flags & G_DBUS_MESSAGE_FLAGS_NO_REPLY_EXPECTED) == 0;
case G_DBUS_MESSAGE_TYPE_SIGNAL:
case G_DBUS_MESSAGE_TYPE_METHOD_RETURN:
case G_DBUS_MESSAGE_TYPE_ERROR:
default:
return FALSE;
}
}
static Buffer *
message_to_buffer (GDBusMessage *message)
{
Buffer *buffer;
guchar *blob;
gsize blob_size;
blob = g_dbus_message_to_blob (message, &blob_size, G_DBUS_CAPABILITY_FLAGS_NONE, NULL);
buffer = buffer_new (blob_size, NULL);
memcpy (buffer->data, blob, blob_size);
buffer->pos = blob_size;
g_free (blob);
return buffer;
}
static GDBusMessage *
get_error_for_header (FlatpakProxyClient *client, Header *header, const char *error)
{
GDBusMessage *reply;
reply = g_dbus_message_new ();
g_dbus_message_set_message_type (reply, G_DBUS_MESSAGE_TYPE_ERROR);
g_dbus_message_set_flags (reply, G_DBUS_MESSAGE_FLAGS_NO_REPLY_EXPECTED);
g_dbus_message_set_reply_serial (reply, header->serial);
g_dbus_message_set_error_name (reply, error);
g_dbus_message_set_body (reply, g_variant_new ("(s)", error));
return reply;
}
static GDBusMessage *
get_bool_reply_for_header (FlatpakProxyClient *client, Header *header, gboolean val)
{
GDBusMessage *reply;
reply = g_dbus_message_new ();
g_dbus_message_set_message_type (reply, G_DBUS_MESSAGE_TYPE_METHOD_RETURN);
g_dbus_message_set_flags (reply, G_DBUS_MESSAGE_FLAGS_NO_REPLY_EXPECTED);
g_dbus_message_set_reply_serial (reply, header->serial);
g_dbus_message_set_body (reply, g_variant_new ("(b)", val));
return reply;
}
static Buffer *
get_ping_buffer_for_header (Header *header)
{
Buffer *buffer;
GDBusMessage *dummy;
dummy = g_dbus_message_new_method_call (NULL, "/", "org.freedesktop.DBus.Peer", "Ping");
g_dbus_message_set_serial (dummy, header->serial);
g_dbus_message_set_flags (dummy, header->flags);
buffer = message_to_buffer (dummy);
g_object_unref (dummy);
return buffer;
}
static Buffer *
get_error_for_roundtrip (FlatpakProxyClient *client, Header *header, const char *error_name)
{
Buffer *ping_buffer = get_ping_buffer_for_header (header);
GDBusMessage *reply;
reply = get_error_for_header (client, header, error_name);
g_hash_table_replace (client->rewrite_reply, GINT_TO_POINTER (header->serial), reply);
return ping_buffer;
}
static Buffer *
get_bool_reply_for_roundtrip (FlatpakProxyClient *client, Header *header, gboolean val)
{
Buffer *ping_buffer = get_ping_buffer_for_header (header);
GDBusMessage *reply;
reply = get_bool_reply_for_header (client, header, val);
g_hash_table_replace (client->rewrite_reply, GINT_TO_POINTER (header->serial), reply);
return ping_buffer;
}
typedef enum {
HANDLE_PASS,
HANDLE_DENY,
HANDLE_HIDE,
HANDLE_FILTER_NAME_LIST_REPLY,
HANDLE_FILTER_HAS_OWNER_REPLY,
HANDLE_FILTER_GET_OWNER_REPLY,
HANDLE_VALIDATE_OWN,
HANDLE_VALIDATE_SEE,
HANDLE_VALIDATE_TALK,
HANDLE_VALIDATE_MATCH,
} BusHandler;
static gboolean
is_for_bus (Header *header)
{
return g_strcmp0 (header->destination, "org.freedesktop.DBus") == 0;
}
static gboolean
is_dbus_method_call (Header *header)
{
return
is_for_bus (header) &&
header->type == G_DBUS_MESSAGE_TYPE_METHOD_CALL &&
g_strcmp0 (header->interface, "org.freedesktop.DBus") == 0;
}
static gboolean
is_introspection_call (Header *header)
{
return
header->type == G_DBUS_MESSAGE_TYPE_METHOD_CALL &&
g_strcmp0 (header->interface, "org.freedesktop.DBus.Introspectable") == 0;
}
static BusHandler
get_dbus_method_handler (FlatpakProxyClient *client, Header *header)
{
FlatpakPolicy policy;
const char *method;
g_autoptr(GList) filters = NULL;
if (header->has_reply_serial)
{
ExpectedReplyType expected_reply =
steal_expected_reply (&client->bus_side,
header->reply_serial);
if (expected_reply == EXPECTED_REPLY_NONE)
return HANDLE_DENY;
return HANDLE_PASS;
}
policy = flatpak_proxy_client_get_max_policy_and_matched (client, header->destination, &filters);
if (policy < FLATPAK_POLICY_SEE)
return HANDLE_HIDE;
if (policy < FLATPAK_POLICY_TALK)
return HANDLE_DENY;
if (!is_for_bus (header))
{
if (policy == FLATPAK_POLICY_OWN ||
any_filter_matches (filters, FILTER_TYPE_CALL,
header->path,
header->interface,
header->member))
return HANDLE_PASS;
return HANDLE_DENY;
}
/* Its a bus call */
if (is_introspection_call (header))
{
return HANDLE_PASS;
}
else if (is_dbus_method_call (header))
{
method = header->member;
if (method == NULL)
return HANDLE_DENY;
if (strcmp (method, "AddMatch") == 0)
return HANDLE_VALIDATE_MATCH;
if (strcmp (method, "Hello") == 0 ||
strcmp (method, "RemoveMatch") == 0 ||
strcmp (method, "GetId") == 0)
return HANDLE_PASS;
if (strcmp (method, "UpdateActivationEnvironment") == 0 ||
strcmp (method, "BecomeMonitor") == 0)
return HANDLE_DENY;
if (strcmp (method, "RequestName") == 0 ||
strcmp (method, "ReleaseName") == 0 ||
strcmp (method, "ListQueuedOwners") == 0)
return HANDLE_VALIDATE_OWN;
if (strcmp (method, "NameHasOwner") == 0)
return HANDLE_FILTER_HAS_OWNER_REPLY;
if (strcmp (method, "GetNameOwner") == 0)
return HANDLE_FILTER_GET_OWNER_REPLY;
if (strcmp (method, "GetConnectionUnixProcessID") == 0 ||
strcmp (method, "GetConnectionCredentials") == 0 ||
strcmp (method, "GetAdtAuditSessionData") == 0 ||
strcmp (method, "GetConnectionSELinuxSecurityContext") == 0 ||
strcmp (method, "GetConnectionUnixUser") == 0)
return HANDLE_VALIDATE_SEE;
if (strcmp (method, "StartServiceByName") == 0)
return HANDLE_VALIDATE_TALK;
if (strcmp (method, "ListNames") == 0 ||
strcmp (method, "ListActivatableNames") == 0)
return HANDLE_FILTER_NAME_LIST_REPLY;
g_warning ("Unknown bus method %s", method);
return HANDLE_DENY;
}
else
{
return HANDLE_DENY;
}
}
static FlatpakPolicy
policy_from_handler (BusHandler handler)
{
switch (handler)
{
case HANDLE_VALIDATE_OWN:
return FLATPAK_POLICY_OWN;
case HANDLE_VALIDATE_TALK:
return FLATPAK_POLICY_TALK;
case HANDLE_VALIDATE_SEE:
return FLATPAK_POLICY_SEE;
case HANDLE_DENY:
case HANDLE_FILTER_GET_OWNER_REPLY:
case HANDLE_FILTER_HAS_OWNER_REPLY:
case HANDLE_FILTER_NAME_LIST_REPLY:
case HANDLE_HIDE:
case HANDLE_PASS:
case HANDLE_VALIDATE_MATCH:
default:
return FLATPAK_POLICY_NONE;
}
}
static char *
get_arg0_string (Buffer *buffer)
{
g_autoptr(GDBusMessage) message =
g_dbus_message_new_from_blob (buffer->data, buffer->size, 0, NULL);
GVariant *body;
g_autoptr(GVariant) arg0 = NULL;
if (message != NULL &&
(body = g_dbus_message_get_body (message)) != NULL &&
(arg0 = g_variant_get_child_value (body, 0)) != NULL &&
g_variant_is_of_type (arg0, G_VARIANT_TYPE_STRING))
return g_variant_dup_string (arg0, NULL);
return NULL;
}
static gboolean
validate_arg0_match (FlatpakProxyClient *client, Buffer *buffer)
{
g_autoptr(GDBusMessage) message =
g_dbus_message_new_from_blob (buffer->data, buffer->size, 0, NULL);
GVariant *body;
g_autoptr(GVariant) arg0 = NULL;
const char *match;
if (message != NULL &&
(body = g_dbus_message_get_body (message)) != NULL &&
(arg0 = g_variant_get_child_value (body, 0)) != NULL &&
g_variant_is_of_type (arg0, G_VARIANT_TYPE_STRING))
{
match = g_variant_get_string (arg0, NULL);
if (strstr (match, "eavesdrop=") != NULL)
return FALSE;
}
return TRUE;
}
static gboolean
validate_arg0_name (FlatpakProxyClient *client, Buffer *buffer, FlatpakPolicy required_policy, FlatpakPolicy *has_policy)
{
g_autoptr(GDBusMessage) message =
g_dbus_message_new_from_blob (buffer->data, buffer->size, 0, NULL);
GVariant *body;
g_autoptr(GVariant) arg0 = NULL;
const char *name;
FlatpakPolicy name_policy;
if (has_policy)
*has_policy = FLATPAK_POLICY_NONE;
if (message != NULL &&
(body = g_dbus_message_get_body (message)) != NULL &&
(arg0 = g_variant_get_child_value (body, 0)) != NULL &&
g_variant_is_of_type (arg0, G_VARIANT_TYPE_STRING))
{
name = g_variant_get_string (arg0, NULL);
name_policy = flatpak_proxy_client_get_max_policy (client, name);
if (has_policy)
*has_policy = name_policy;
if (name_policy >= required_policy)
return TRUE;
if (client->proxy->log_messages)
g_print ("Filtering message due to arg0 %s, policy: %d (required %d)\n", name, name_policy, required_policy);
}
return FALSE;
}
static Buffer *
filter_names_list (FlatpakProxyClient *client, Buffer *buffer)
{
g_autoptr(GDBusMessage) message =
g_dbus_message_new_from_blob (buffer->data, buffer->size, 0, NULL);
GVariant *body, *new_names;
g_autoptr(GVariant) arg0 = NULL;
const gchar **names;
int i;
GVariantBuilder builder;
Buffer *filtered;
if (message == NULL ||
(body = g_dbus_message_get_body (message)) == NULL ||
(arg0 = g_variant_get_child_value (body, 0)) == NULL ||
!g_variant_is_of_type (arg0, G_VARIANT_TYPE_STRING_ARRAY))
return NULL;
names = g_variant_get_strv (arg0, NULL);
g_variant_builder_init (&builder, G_VARIANT_TYPE_STRING_ARRAY);
for (i = 0; names[i] != NULL; i++)
{
if (flatpak_proxy_client_get_max_policy (client, names[i]) >= FLATPAK_POLICY_SEE)
g_variant_builder_add (&builder, "s", names[i]);
}
g_free (names);
new_names = g_variant_builder_end (&builder);
g_dbus_message_set_body (message,
g_variant_new_tuple (&new_names, 1));
filtered = message_to_buffer (message);
return filtered;
}
static gboolean
message_is_name_owner_changed (FlatpakProxyClient *client, Header *header)
{
if (header->type == G_DBUS_MESSAGE_TYPE_SIGNAL &&
g_strcmp0 (header->sender, "org.freedesktop.DBus") == 0 &&
g_strcmp0 (header->interface, "org.freedesktop.DBus") == 0 &&
g_strcmp0 (header->member, "NameOwnerChanged") == 0)
return TRUE;
return FALSE;
}
static gboolean
should_filter_name_owner_changed (FlatpakProxyClient *client, Buffer *buffer)
{
g_autoptr(GDBusMessage) message =
g_dbus_message_new_from_blob (buffer->data, buffer->size, 0, NULL);
GVariant *body;
g_autoptr(GVariant) arg0 = NULL;
g_autoptr(GVariant) arg1 = NULL;
g_autoptr(GVariant) arg2 = NULL;
const gchar *name, *new;
if (message == NULL ||
(body = g_dbus_message_get_body (message)) == NULL ||
(arg0 = g_variant_get_child_value (body, 0)) == NULL ||
!g_variant_is_of_type (arg0, G_VARIANT_TYPE_STRING) ||
(arg1 = g_variant_get_child_value (body, 1)) == NULL ||
!g_variant_is_of_type (arg1, G_VARIANT_TYPE_STRING) ||
(arg2 = g_variant_get_child_value (body, 2)) == NULL ||
!g_variant_is_of_type (arg2, G_VARIANT_TYPE_STRING))
return TRUE;
name = g_variant_get_string (arg0, NULL);
new = g_variant_get_string (arg2, NULL);
if (flatpak_proxy_client_get_max_policy (client, name) >= FLATPAK_POLICY_SEE ||
(client->proxy->sloppy_names && name[0] == ':'))
{
if (name[0] != ':')
{
if (new[0] != 0)
flatpak_proxy_client_add_unique_id_owned_name (client, new, name);
}
return FALSE;
}
return TRUE;
}
static GList *
side_get_n_unix_fds (ProxySide *side, int n_fds)
{
GList *res = NULL;
while (side->control_messages != NULL)
{
GSocketControlMessage *control_message = side->control_messages->data;
if (G_IS_UNIX_FD_MESSAGE (control_message))
{
GUnixFDMessage *fd_message = G_UNIX_FD_MESSAGE (control_message);
GUnixFDList *fd_list = g_unix_fd_message_get_fd_list (fd_message);
int len = g_unix_fd_list_get_length (fd_list);
/* I believe that socket control messages are never merged, and
the sender side sends only one unix-fd-list per message, so
at this point there should always be one full fd list
per requested number of fds */
if (len != n_fds)
{
g_warning ("Not right nr of fds in socket message");
return NULL;
}
side->control_messages = g_list_delete_link (side->control_messages, side->control_messages);
return g_list_append (NULL, control_message);
}
g_object_unref (control_message);
side->control_messages = g_list_delete_link (side->control_messages, side->control_messages);
}
return res;
}
static gboolean
update_socket_messages (ProxySide *side, Buffer *buffer, Header *header)
{
/* We may accidentally combine multiple control messages into one
buffer when we receive (since we can do several recvs), so we
keep a list of all we get and then only re-attach the amount
specified in the header to the buffer. */
side->control_messages = g_list_concat (side->control_messages, buffer->control_messages);
buffer->control_messages = NULL;
if (header->unix_fds > 0)
{
buffer->control_messages = side_get_n_unix_fds (side, header->unix_fds);
if (buffer->control_messages == NULL)
{
g_warning ("Not enough fds for message");
side_closed (side);
buffer_unref (buffer);
return FALSE;
}
}
return TRUE;
}
static void
queue_fake_message (FlatpakProxyClient *client, GDBusMessage *message, ExpectedReplyType reply_type)
{
Buffer *buffer;
client->last_fake_serial++;
g_assert (client->last_fake_serial > MAX_CLIENT_SERIAL);
g_dbus_message_set_serial (message, client->last_fake_serial);
buffer = message_to_buffer (message);
g_object_unref (message);
queue_outgoing_buffer (&client->bus_side, buffer);
queue_expected_reply (&client->client_side, client->last_fake_serial, reply_type);
}
/* After the first Hello message we need to synthesize a bunch of messages to synchronize the
ownership state for the names in the policy */
static void
queue_initial_name_ops (FlatpakProxyClient *client)
{
GHashTableIter iter;
gpointer key, value;
gboolean has_wildcards = FALSE;
g_hash_table_iter_init (&iter, client->proxy->filters);
while (g_hash_table_iter_next (&iter, &key, &value))
{
const char *name = key;
GList *filters = value;
gboolean name_needs_subtree = FALSE;
GDBusMessage *message;
GVariant *match;
GList *l;
for (l = filters; l != NULL; l = l->next)
{
Filter *filter = l->data;
if (filter->name_is_subtree)
{
name_needs_subtree = TRUE;
break;
}
}
if (strcmp (name, "org.freedesktop.DBus") == 0)
continue;
/* AddMatch the name so we get told about ownership changes.
Do it before the GetNameOwner to avoid races */
message = g_dbus_message_new_method_call ("org.freedesktop.DBus", "/", "org.freedesktop.DBus", "AddMatch");
if (name_needs_subtree)
match = g_variant_new_printf ("type='signal',sender='org.freedesktop.DBus',interface='org.freedesktop.DBus',member='NameOwnerChanged',arg0namespace='%s'", name);
else
match = g_variant_new_printf ("type='signal',sender='org.freedesktop.DBus',interface='org.freedesktop.DBus',member='NameOwnerChanged',arg0='%s'", name);
g_dbus_message_set_body (message, g_variant_new_tuple (&match, 1));
queue_fake_message (client, message, EXPECTED_REPLY_FILTER);
if (client->proxy->log_messages)
g_print ("C%d: -> org.freedesktop.DBus fake %sAddMatch for %s\n", client->last_fake_serial, name_needs_subtree ? "wildcarded " : "", name);
if (!name_needs_subtree)
{
/* Get the current owner of the name (if any) so we can apply policy to it */
message = g_dbus_message_new_method_call ("org.freedesktop.DBus", "/", "org.freedesktop.DBus", "GetNameOwner");
g_dbus_message_set_body (message, g_variant_new ("(s)", name));
queue_fake_message (client, message, EXPECTED_REPLY_FAKE_GET_NAME_OWNER);
g_hash_table_replace (client->get_owner_reply, GINT_TO_POINTER (client->last_fake_serial), g_strdup (name));
if (client->proxy->log_messages)
g_print ("C%d: -> org.freedesktop.DBus fake GetNameOwner for %s\n", client->last_fake_serial, name);
}
else
has_wildcards = TRUE; /* Send ListNames below */
}
/* For wildcarded rules we don't know the actual names to GetNameOwner for, so we have to list all current names */
if (has_wildcards)
{
GDBusMessage *message;
/* AddMatch the name so we get told about ownership changes.
Do it before the GetNameOwner to avoid races */
message = g_dbus_message_new_method_call ("org.freedesktop.DBus", "/", "org.freedesktop.DBus", "ListNames");
g_dbus_message_set_body (message, g_variant_new ("()"));
queue_fake_message (client, message, EXPECTED_REPLY_FAKE_LIST_NAMES);
if (client->proxy->log_messages)
g_print ("C%d: -> org.freedesktop.DBus fake ListNames\n", client->last_fake_serial);
/* Stop reading from the client, to avoid incoming messages fighting with the ListNames roundtrip.
We will start it again once we have handled the ListNames reply */
stop_reading (&client->client_side);
/* Once we get the reply to this queue_wildcard_initial_name_ops() will be called and we continue there */
}
}
static void
queue_wildcard_initial_name_ops (FlatpakProxyClient *client, Header *header, Buffer *buffer)
{
g_autoptr(GDBusMessage) decoded_message =
g_dbus_message_new_from_blob (buffer->data, buffer->size, 0, NULL);
GVariant *body;
g_autoptr(GVariant) arg0 = NULL;
g_autofree const gchar **names = NULL;
int i;
if (decoded_message == NULL ||
header->type != G_DBUS_MESSAGE_TYPE_METHOD_RETURN ||
(body = g_dbus_message_get_body (decoded_message)) == NULL ||
(arg0 = g_variant_get_child_value (body, 0)) == NULL ||
!g_variant_is_of_type (arg0, G_VARIANT_TYPE_STRING_ARRAY))
return;
names = g_variant_get_strv (arg0, NULL);
/* Loop over all current names and get the owner for all the ones that match our rules
policies so that we can update the unique id policies for those */
for (i = 0; names[i] != NULL; i++)
{
const char *name = names[i];
if (name[0] != ':' &&
flatpak_proxy_client_get_max_policy (client, name) != FLATPAK_POLICY_NONE)
{
/* Get the current owner of the name (if any) so we can apply policy to it */
GDBusMessage *message = g_dbus_message_new_method_call ("org.freedesktop.DBus", "/", "org.freedesktop.DBus", "GetNameOwner");
g_dbus_message_set_body (message, g_variant_new ("(s)", name));
queue_fake_message (client, message, EXPECTED_REPLY_FAKE_GET_NAME_OWNER);
g_hash_table_replace (client->get_owner_reply, GINT_TO_POINTER (client->last_fake_serial), g_strdup (name));
if (client->proxy->log_messages)
g_print ("C%d: -> org.freedesktop.DBus fake GetNameOwner for %s\n", client->last_fake_serial, name);
}
}
}
static void
got_buffer_from_client (FlatpakProxyClient *client, ProxySide *side, Buffer *buffer)
{
ExpectedReplyType expecting_reply = EXPECTED_REPLY_NONE;
if (client->auth_state == AUTH_COMPLETE && client->proxy->filter)
{
g_autoptr(Header) header = NULL;
g_autoptr(GError) error = NULL;
BusHandler handler;
/* Filter and rewrite outgoing messages as needed */
header = parse_header (buffer, &error);
if (header == NULL)
{
g_warning ("Invalid message header format from client: %s",
error->message);
side_closed (side);
buffer_unref (buffer);
return;
}
if (!update_socket_messages (side, buffer, header))
return;
if (header->serial > MAX_CLIENT_SERIAL)
{
g_warning ("Invalid client serial: Exceeds maximum value of %u", MAX_CLIENT_SERIAL);
side_closed (side);
buffer_unref (buffer);
return;
}
if (client->proxy->log_messages)
print_outgoing_header (header);
/* Keep track of the initial Hello request so that we can read
the reply which has our assigned unique id */
if (is_dbus_method_call (header) &&
g_strcmp0 (header->member, "Hello") == 0)
{
expecting_reply = EXPECTED_REPLY_HELLO;
client->hello_serial = header->serial;
}
handler = get_dbus_method_handler (client, header);
switch (handler)
{
case HANDLE_FILTER_HAS_OWNER_REPLY:
case HANDLE_FILTER_GET_OWNER_REPLY:
if (!validate_arg0_name (client, buffer, FLATPAK_POLICY_SEE, NULL))
{
g_clear_pointer (&buffer, buffer_unref);
if (handler == HANDLE_FILTER_GET_OWNER_REPLY)
buffer = get_error_for_roundtrip (client, header,
"org.freedesktop.DBus.Error.NameHasNoOwner");
else
buffer = get_bool_reply_for_roundtrip (client, header, FALSE);
expecting_reply = EXPECTED_REPLY_REWRITE;
break;
}
goto handle_pass;
case HANDLE_VALIDATE_MATCH:
if (!validate_arg0_match (client, buffer))
{
if (client->proxy->log_messages)
g_print ("*DENIED* (ping)\n");
g_clear_pointer (&buffer, buffer_unref);
buffer = get_error_for_roundtrip (client, header,
"org.freedesktop.DBus.Error.AccessDenied");
expecting_reply = EXPECTED_REPLY_REWRITE;
break;
}
goto handle_pass;
case HANDLE_VALIDATE_OWN:
case HANDLE_VALIDATE_SEE:
case HANDLE_VALIDATE_TALK:
{
FlatpakPolicy name_policy;
if (validate_arg0_name (client, buffer, policy_from_handler (handler), &name_policy))
goto handle_pass;
if (name_policy < (int) FLATPAK_POLICY_SEE)
goto handle_hide;
else
goto handle_deny;
}
case HANDLE_FILTER_NAME_LIST_REPLY:
expecting_reply = EXPECTED_REPLY_LIST_NAMES;
goto handle_pass;
case HANDLE_PASS:
handle_pass:
if (client_message_generates_reply (header))
{
if (expecting_reply == EXPECTED_REPLY_NONE)
expecting_reply = EXPECTED_REPLY_NORMAL;
}
break;
case HANDLE_HIDE:
handle_hide:
g_clear_pointer (&buffer, buffer_unref);
if (client_message_generates_reply (header))
{
const char *error_str;
if (client->proxy->log_messages)
g_print ("*HIDDEN* (ping)\n");
if ((header->destination != NULL && header->destination[0] == ':') ||
(header->flags & G_DBUS_MESSAGE_FLAGS_NO_AUTO_START) != 0)
error_str = "org.freedesktop.DBus.Error.NameHasNoOwner";
else
error_str = "org.freedesktop.DBus.Error.ServiceUnknown";
buffer = get_error_for_roundtrip (client, header, error_str);
expecting_reply = EXPECTED_REPLY_REWRITE;
}
else
{
if (client->proxy->log_messages)
g_print ("*HIDDEN*\n");
}
break;
default:
case HANDLE_DENY:
handle_deny:
g_clear_pointer (&buffer, buffer_unref);
if (client_message_generates_reply (header))
{
if (client->proxy->log_messages)
g_print ("*DENIED* (ping)\n");
buffer = get_error_for_roundtrip (client, header,
"org.freedesktop.DBus.Error.AccessDenied");
expecting_reply = EXPECTED_REPLY_REWRITE;
}
else
{
if (client->proxy->log_messages)
g_print ("*DENIED*\n");
}
break;
}
if (buffer != NULL && expecting_reply != EXPECTED_REPLY_NONE)
queue_expected_reply (side, header->serial, expecting_reply);
}
if (buffer)
queue_outgoing_buffer (&client->bus_side, buffer);
if (buffer != NULL && expecting_reply == EXPECTED_REPLY_HELLO)
queue_initial_name_ops (client);
}
static void
got_buffer_from_bus (FlatpakProxyClient *client, ProxySide *side, Buffer *buffer)
{
if (client->auth_state == AUTH_COMPLETE && client->proxy->filter)
{
g_autoptr(Header) header = NULL;
g_autoptr(GError) error = NULL;
GDBusMessage *rewritten;
FlatpakPolicy policy;
ExpectedReplyType expected_reply;
/* Filter and rewrite incoming messages as needed */
header = parse_header (buffer, &error);
if (header == NULL)
{
g_warning ("Invalid message header format from bus: %s",
error->message);
buffer_unref (buffer);
side_closed (side);
return;
}
if (!update_socket_messages (side, buffer, header))
return;
if (client->proxy->log_messages)
print_incoming_header (header);
if (header->has_reply_serial)
{
expected_reply = steal_expected_reply (get_other_side (side), header->reply_serial);
switch (expected_reply)
{
case EXPECTED_REPLY_NONE:
/* We only allow replies we expect */
if (client->proxy->log_messages)
g_print ("*Unexpected reply*\n");
buffer_unref (buffer);
return;
case EXPECTED_REPLY_HELLO:
/* When we get the initial reply to Hello, allow all
further communications to our own unique id. */
if (header->type == G_DBUS_MESSAGE_TYPE_METHOD_RETURN)
{
g_autofree char *my_id = get_arg0_string (buffer);
flatpak_proxy_client_update_unique_id_policy (client, my_id, FLATPAK_POLICY_TALK);
}
/* ... else it's an ERROR or something. Either way, pass it
* through to the client unedited. */
break;
case EXPECTED_REPLY_REWRITE:
/* Replace a roundtrip ping with the rewritten message */
rewritten = g_hash_table_lookup (client->rewrite_reply,
GINT_TO_POINTER (header->reply_serial));
if (client->proxy->log_messages)
g_print ("*REWRITTEN*\n");
g_dbus_message_set_serial (rewritten, header->serial);
g_clear_pointer (&buffer, buffer_unref);
buffer = message_to_buffer (rewritten);
g_hash_table_remove (client->rewrite_reply,
GINT_TO_POINTER (header->reply_serial));
break;
case EXPECTED_REPLY_FAKE_LIST_NAMES:
/* This is a reply from the bus to a fake ListNames
request, request ownership of any name matching a
wildcard policy */
queue_wildcard_initial_name_ops (client, header, buffer);
/* Don't forward fake replies to the app */
if (client->proxy->log_messages)
g_print ("*SKIPPED*\n");
g_clear_pointer (&buffer, buffer_unref);
/* Start reading the clients requests now that we are done with the names */
start_reading (&client->client_side);
break;
case EXPECTED_REPLY_FAKE_GET_NAME_OWNER:
/* This is a reply from the bus to a fake GetNameOwner
request, update the policy for this unique name based on
the policy */
{
char *requested_name = g_hash_table_lookup (client->get_owner_reply, GINT_TO_POINTER (header->reply_serial));
if (header->type == G_DBUS_MESSAGE_TYPE_METHOD_RETURN)
{
g_autofree char *owner = get_arg0_string (buffer);
flatpak_proxy_client_add_unique_id_owned_name (client, owner, requested_name);
}
g_hash_table_remove (client->get_owner_reply, GINT_TO_POINTER (header->reply_serial));
/* Don't forward fake replies to the app */
if (client->proxy->log_messages)
g_print ("*SKIPPED*\n");
g_clear_pointer (&buffer, buffer_unref);
break;
}
case EXPECTED_REPLY_FILTER:
if (client->proxy->log_messages)
g_print ("*SKIPPED*\n");
g_clear_pointer (&buffer, buffer_unref);
break;
case EXPECTED_REPLY_LIST_NAMES:
/* This is a reply from the bus to a ListNames request, filter
it according to the policy */
if (header->type == G_DBUS_MESSAGE_TYPE_METHOD_RETURN)
{
Buffer *filtered_buffer;
filtered_buffer = filter_names_list (client, buffer);
g_clear_pointer (&buffer, buffer_unref);
buffer = filtered_buffer;
}
break;
case EXPECTED_REPLY_NORMAL:
break;
default:
g_warning ("Unexpected expected reply type %d", expected_reply);
}
}
else /* Not reply */
{
/* Don't allow reply types with no reply_serial */
if (header->type == G_DBUS_MESSAGE_TYPE_METHOD_RETURN ||
header->type == G_DBUS_MESSAGE_TYPE_ERROR)
{
if (client->proxy->log_messages)
g_print ("*Invalid reply*\n");
g_clear_pointer (&buffer, buffer_unref);
}
/* We filter all NameOwnerChanged signal according to the policy */
if (message_is_name_owner_changed (client, header))
{
if (should_filter_name_owner_changed (client, buffer))
g_clear_pointer (&buffer, buffer_unref);
}
}
/* All incoming broadcast signals are filtered according to policy */
if (header->type == G_DBUS_MESSAGE_TYPE_SIGNAL && header->destination == NULL)
{
g_autoptr(GList) filters = NULL;
gboolean filtered = TRUE;
policy = flatpak_proxy_client_get_max_policy_and_matched (client, header->sender, &filters);
if (policy == FLATPAK_POLICY_OWN ||
policy == FLATPAK_POLICY_TALK ||
any_filter_matches (filters, FILTER_TYPE_BROADCAST,
header->path,
header->interface,
header->member))
filtered = FALSE;
if (filtered)
{
if (client->proxy->log_messages)
g_print ("*FILTERED IN*\n");
g_clear_pointer (&buffer, buffer_unref);
}
}
/* We received and forwarded a message from a trusted peer. Make the policy for
this unique id SEE so that the client can track its lifetime. */
if (buffer && header->sender && header->sender[0] == ':')
flatpak_proxy_client_update_unique_id_policy (client, header->sender, FLATPAK_POLICY_SEE);
if (buffer && client_message_generates_reply (header))
queue_expected_reply (side, header->serial, EXPECTED_REPLY_NORMAL);
}
if (buffer)
queue_outgoing_buffer (&client->client_side, buffer);
}
static void
got_buffer_from_side (ProxySide *side, Buffer *buffer)
{
FlatpakProxyClient *client = side->client;
if (side == &client->client_side)
got_buffer_from_client (client, side, buffer);
else
got_buffer_from_bus (client, side, buffer);
}
#define _DBUS_ISASCII(c) ((c) != '\0' && (((c) & ~0x7f) == 0))
static gboolean
auth_line_is_valid (guint8 *line, guint8 *line_end)
{
guint8 *p;
for (p = line; p < line_end; p++)
{
if (!_DBUS_ISASCII (*p))
return FALSE;
/* Technically, the dbus spec allows all ASCII characters, but for robustness we also
fail if we see any control characters. Such low values will appear in potential attacks,
but will never happen in real sasl (where all binary data is hex encoded). */
if (*p < ' ')
return FALSE;
}
/* For robustness we require the first char of the line to be an upper case letter.
This is not technically required by the dbus spec, but all commands are upper
case, and there is no provisioning for whitespace before the command, so in practice
this is true, and this means we're not confused by e.g. initial whitespace. */
if (line[0] < 'A' || line[0] > 'Z')
return FALSE;
return TRUE;
}
static gboolean
auth_line_is_begin (guint8 *line)
{
guint8 next_char;
if (!g_str_has_prefix ((char *) line, AUTH_BEGIN))
return FALSE;
/* dbus-daemon accepts either nothing, or a whitespace followed by anything as end of auth */
next_char = line[strlen (AUTH_BEGIN)];
return next_char == 0 ||
next_char == ' ' ||
next_char == '\t';
}
static guint8 *
find_auth_line_end (guint8 *line_start, gsize buffer_size)
{
return memmem (line_start, buffer_size,
AUTH_LINE_SENTINEL, strlen (AUTH_LINE_SENTINEL));
}
static gssize
find_auth_end (FlatpakProxyClient *client, Buffer *buffer, gsize *out_lines_skipped)
{
goffset offset = 0;
gsize original_size = client->auth_buffer->len;
gsize lines_skipped = 0;
/* Add the new data to the remaining data from last iteration */
g_byte_array_append (client->auth_buffer, buffer->data, buffer->pos);
while (TRUE)
{
guint8 *line_start = client->auth_buffer->data + offset;
gsize remaining_data = client->auth_buffer->len - offset;
guint8 *line_end;
line_end = find_auth_line_end (line_start, remaining_data);
if (line_end) /* Found end of line */
{
offset = (line_end + strlen (AUTH_LINE_SENTINEL) - client->auth_buffer->data);
if (!auth_line_is_valid (line_start, line_end))
return FIND_AUTH_END_ABORT;
*line_end = 0;
if (auth_line_is_begin (line_start))
{
*out_lines_skipped = lines_skipped;
return offset - original_size;
}
/* continue with next line */
++lines_skipped;
}
else
{
/* No more end-of-line in this buffer */
*out_lines_skipped = lines_skipped;
g_byte_array_remove_range (client->auth_buffer, 0, offset);
/* Abort if more than 16k before newline, similar to what dbus-daemon does */
if (client->auth_buffer->len >= 16 * 1024)
return FIND_AUTH_END_ABORT;
return FIND_AUTH_END_CONTINUE;
}
}
}
static gboolean
side_in_cb (GSocket *socket, GIOCondition condition, gpointer user_data)
{
ProxySide *side = user_data;
FlatpakProxyClient *client = side->client;
GError *error = NULL;
Buffer *buffer;
gboolean retval = G_SOURCE_CONTINUE;
gboolean wake_client_reader = FALSE;
g_object_ref (client);
while (!side->closed)
{
if (!side->got_first_byte)
buffer = buffer_new (1, NULL);
else if (client->auth_state != AUTH_COMPLETE)
buffer = buffer_new (256, NULL);
else
buffer = side->current_read_buffer;
if (!buffer_read (side, buffer, socket))
{
if (buffer != side->current_read_buffer)
buffer_unref (buffer);
break;
}
if (client->auth_state != AUTH_COMPLETE)
{
if (buffer->pos == 0)
{
buffer_unref (buffer);
continue;
}
/* The state of the client after handling this buffer */
AuthState new_auth_state = client->auth_state;
buffer->size = buffer->pos;
if (!side->got_first_byte)
{
buffer->send_credentials = TRUE;
side->got_first_byte = TRUE;
}
/* Look for end of authentication mechanism */
else if (side == &client->client_side && client->auth_state == AUTH_WAITING_FOR_BEGIN)
{
gsize lines_skipped = 0;
gssize auth_end = find_auth_end (client, buffer, &lines_skipped);
client->auth_requests += lines_skipped;
if (auth_end >= 0)
{
gsize extra_data;
if (client->auth_replies == client->auth_requests)
new_auth_state = AUTH_COMPLETE;
else
new_auth_state = AUTH_WAITING_FOR_BACKLOG;
extra_data = buffer->pos - auth_end;
buffer->size = buffer->pos = auth_end;
/* We may have gotten some extra data which is not part of
the auth handshake, keep it for the next iteration. */
if (extra_data > 0)
side->extra_input_data = g_bytes_new (buffer->data + buffer->size, extra_data);
}
else if (auth_end == FIND_AUTH_END_ABORT)
{
buffer_unref (buffer);
if (client->proxy->log_messages)
g_print ("Invalid AUTH line, aborting\n");
side_closed (side);
break;
}
}
else if (side == &client->bus_side)
{
gsize remaining = buffer->pos;
guint8 *line_start = buffer->data;
while (remaining > 0)
{
guint8 *line_end = NULL;
if (client->auth_replies == client->auth_requests)
{
buffer_unref (buffer);
if (client->proxy->log_messages)
g_print ("Unexpected auth reply line from bus, aborting\n");
side_closed (side);
break;
}
line_end = find_auth_line_end (line_start, remaining);
if (line_end == NULL)
line_end = line_start + remaining;
else
{
line_end += strlen (AUTH_LINE_SENTINEL);
client->auth_replies++;
}
remaining -= line_end - line_start;
line_start = line_end;
if (client->auth_state == AUTH_WAITING_FOR_BACKLOG &&
client->auth_replies == client->auth_requests)
{
new_auth_state = AUTH_COMPLETE;
/* We may have added extra data on the input, ensure we read it directly */
wake_client_reader = TRUE;
buffer->pos = buffer->size = line_start - buffer->data;
/* We may have gotten some extra data which is not part of
the auth handshake, keep it for the next iteration. */
if (remaining > 0)
side->extra_input_data = g_bytes_new (line_start, remaining);
break;
}
}
}
got_buffer_from_side (side, buffer);
client->auth_state = new_auth_state;
}
else if (buffer->pos == buffer->size)
{
if (buffer == &side->header_buffer)
{
gssize required;
required = g_dbus_message_bytes_needed (buffer->data, buffer->size, &error);
if (required < 0)
{
g_warning ("Invalid message header read");
side_closed (side);
}
else
{
side->current_read_buffer = buffer_new (required, buffer);
}
}
else
{
got_buffer_from_side (side, buffer);
side->header_buffer.pos = 0;
side->current_read_buffer = &side->header_buffer;
}
}
}
if (side->closed)
{
side->in_source = NULL;
retval = G_SOURCE_REMOVE;
}
else if (wake_client_reader)
{
GSocket *client_socket = g_socket_connection_get_socket (client->client_side.connection);
side_in_cb (client_socket, G_IO_IN, &client->client_side);
}
g_object_unref (client);
return retval;
}
static void
start_reading (ProxySide *side)
{
GSocket *socket;
socket = g_socket_connection_get_socket (side->connection);
side->in_source = g_socket_create_source (socket, G_IO_IN, NULL);
g_source_set_callback (side->in_source, G_SOURCE_FUNC (side_in_cb), side, NULL);
g_source_attach (side->in_source, NULL);
g_source_unref (side->in_source);
}
static void
stop_reading (ProxySide *side)
{
if (side->in_source)
{
g_source_destroy (side->in_source);
side->in_source = NULL;
}
}
static void
client_connected_to_dbus (GObject *source_object,
GAsyncResult *res,
gpointer user_data)
{
FlatpakProxyClient *client = user_data;
GSocketConnection *connection;
GError *error = NULL;
GIOStream *stream;
stream = g_dbus_address_get_stream_finish (res, NULL, &error);
if (stream == NULL)
{
g_warning ("Failed to connect to bus: %s", error->message);
g_object_unref (client);
return;
}
connection = G_SOCKET_CONNECTION (stream);
g_socket_set_blocking (g_socket_connection_get_socket (connection), FALSE);
client->bus_side.connection = connection;
start_reading (&client->client_side);
start_reading (&client->bus_side);
}
static gboolean
flatpak_proxy_incoming (GSocketService *service,
GSocketConnection *connection,
GObject *source_object)
{
FlatpakProxy *proxy = FLATPAK_PROXY (service);
FlatpakProxyClient *client;
client = flatpak_proxy_client_new (proxy, connection);
g_dbus_address_get_stream (proxy->dbus_address,
NULL,
client_connected_to_dbus,
client);
return TRUE;
}
static void
flatpak_proxy_init (FlatpakProxy *proxy)
{
proxy->filters = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, (GDestroyNotify) filter_list_free);
flatpak_proxy_add_policy (proxy, "org.freedesktop.DBus", FALSE, FLATPAK_POLICY_TALK);
}
static void
flatpak_proxy_class_init (FlatpakProxyClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
GSocketServiceClass *socket_service_class = G_SOCKET_SERVICE_CLASS (klass);
object_class->get_property = flatpak_proxy_get_property;
object_class->set_property = flatpak_proxy_set_property;
object_class->finalize = flatpak_proxy_finalize;
socket_service_class->incoming = flatpak_proxy_incoming;
g_object_class_install_property (object_class,
PROP_DBUS_ADDRESS,
g_param_spec_string ("dbus-address",
"",
"",
NULL,
G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
g_object_class_install_property (object_class,
PROP_SOCKET_PATH,
g_param_spec_string ("socket-path",
"",
"",
NULL,
G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
}
FlatpakProxy *
flatpak_proxy_new (const char *dbus_address,
const char *socket_path)
{
FlatpakProxy *proxy;
proxy = g_object_new (FLATPAK_TYPE_PROXY, "dbus-address", dbus_address, "socket-path", socket_path, NULL);
return proxy;
}
gboolean
flatpak_proxy_start (FlatpakProxy *proxy, GError **error)
{
GSocketAddress *address;
gboolean res;
unlink (proxy->socket_path);
address = g_unix_socket_address_new (proxy->socket_path);
res = g_socket_listener_add_address (G_SOCKET_LISTENER (proxy),
address,
G_SOCKET_TYPE_STREAM,
G_SOCKET_PROTOCOL_DEFAULT,
NULL, /* source_object */
NULL, /* effective_address */
error);
g_object_unref (address);
if (!res)
return FALSE;
g_socket_service_start (G_SOCKET_SERVICE (proxy));
return TRUE;
}
void
flatpak_proxy_stop (FlatpakProxy *proxy)
{
unlink (proxy->socket_path);
g_socket_service_stop (G_SOCKET_SERVICE (proxy));
}
|