File: rtnl_rule.c

package info (click to toggle)
strace 4.26-0.2
  • links: PTS, VCS
  • area: main
  • in suites: buster
  • size: 35,988 kB
  • sloc: ansic: 95,598; sh: 7,155; makefile: 2,489; awk: 335; perl: 267; sed: 6
file content (152 lines) | stat: -rw-r--r-- 3,855 bytes parent folder | download
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
/*
 * Copyright (c) 2016 Fabien Siron <fabien.siron@epita.fr>
 * Copyright (c) 2017 JingPiao Chen <chenjingpiao@gmail.com>
 * Copyright (c) 2016-2018 The strace developers.
 * All rights reserved.
 *
 * SPDX-License-Identifier: LGPL-2.1-or-later
 */

#include "defs.h"

#include "netlink_route.h"
#include "nlattr.h"
#include "print_fields.h"

#include "netlink.h"
#include <linux/rtnetlink.h>
#ifdef HAVE_LINUX_FIB_RULES_H
# include <linux/fib_rules.h>
#endif

#include "xlat/fib_rule_actions.h"
#include "xlat/fib_rule_flags.h"
#include "xlat/rtnl_rule_attrs.h"

static bool
decode_rule_addr(struct tcb *const tcp,
		 const kernel_ulong_t addr,
		 const unsigned int len,
		 const void *const opaque_data)
{
	const struct rtmsg *const rtmsg = opaque_data;

	decode_inet_addr(tcp, addr, len, rtmsg->rtm_family, NULL);

	return true;
}

static bool
decode_fib_rule_uid_range(struct tcb *const tcp,
			  const kernel_ulong_t addr,
			  const unsigned int len,
			  const void *const opaque_data)
{
#ifdef HAVE_STRUCT_FIB_RULE_UID_RANGE
	struct fib_rule_uid_range range;

	if (len < sizeof(range))
		return false;
	else if (!umove_or_printaddr(tcp, addr, &range)) {
		PRINT_FIELD_U("{", range, start);
		PRINT_FIELD_U(", ", range, end);
		tprints("}");
	}

	return true;
#else
	return false;
#endif
}

static bool
decode_rule_port_range(struct tcb *const tcp,
		       const kernel_ulong_t addr,
		       const unsigned int len,
		       const void *const opaque_data)
{
	struct /* fib_rule_port_range */ {
		uint16_t start;
		uint16_t end;
	} range;

	if (len < sizeof(range))
		return false;
	else if (!umove_or_printaddr(tcp, addr, &range)) {
		PRINT_FIELD_U("{", range, start);
		PRINT_FIELD_U(", ", range, end);
		tprints("}");
	}

	return true;
}

static const nla_decoder_t fib_rule_hdr_nla_decoders[] = {
	[FRA_DST]			= decode_rule_addr,
	[FRA_SRC]			= decode_rule_addr,
	[FRA_IIFNAME]			= decode_nla_str,
	[FRA_GOTO]			= decode_nla_u32,
	[FRA_PRIORITY]			= decode_nla_u32,
	[FRA_FWMARK]			= decode_nla_u32,
	[FRA_FLOW]			= decode_nla_u32,
	[FRA_TUN_ID]			= decode_nla_be64,
	[FRA_SUPPRESS_IFGROUP]		= decode_nla_u32,
	[FRA_SUPPRESS_PREFIXLEN]	= decode_nla_u32,
	[FRA_TABLE]			= decode_nla_rt_class,
	[FRA_FWMASK]			= decode_nla_u32,
	[FRA_OIFNAME]			= decode_nla_str,
	[FRA_PAD]			= NULL,
	[FRA_L3MDEV]			= decode_nla_u8,
	[FRA_UID_RANGE]			= decode_fib_rule_uid_range,
	[FRA_PROTOCOL]			= decode_nla_rt_proto,
	[FRA_IP_PROTO]			= decode_nla_ip_proto,
	[FRA_SPORT_RANGE]		= decode_rule_port_range,
	[FRA_DPORT_RANGE]		= decode_rule_port_range,
};

DECL_NETLINK_ROUTE_DECODER(decode_fib_rule_hdr)
{
	/*
	 * struct rtmsg and struct fib_rule_hdr are essentially
	 * the same structure, use struct rtmsg but treat it as
	 * struct fib_rule_hdr.
	 */
	struct rtmsg msg = { .rtm_family = family };
	size_t offset = sizeof(msg.rtm_family);
	bool decode_nla = false;

	tprints("{family=");
	printxval(addrfams, msg.rtm_family, "AF_???");

	tprints(", ");
	if (len >= sizeof(msg)) {
		if (!umoven_or_printaddr(tcp, addr + offset,
					 sizeof(msg) - offset,
					 (char *) &msg + offset)) {
			tprintf("dst_len=%u, src_len=%u",
				msg.rtm_dst_len, msg.rtm_src_len);
			tprints(", tos=");
			printflags(ip_type_of_services, msg.rtm_tos,
				   "IPTOS_TOS_???");
			tprints(", table=");
			printxval(routing_table_ids, msg.rtm_table, NULL);
			tprints(", action=");
			printxval(fib_rule_actions, msg.rtm_type, "FR_ACT_???");
			tprints(", flags=");
			printflags(fib_rule_flags, msg.rtm_flags,
				   "FIB_RULE_???");
			decode_nla = true;
		}
	} else
		tprints("...");
	tprints("}");

	offset = NLMSG_ALIGN(sizeof(msg));
	if (decode_nla && len > offset) {
		tprints(", ");
		decode_nlattr(tcp, addr + offset, len - offset,
			      rtnl_rule_attrs, "FRA_???",
			      fib_rule_hdr_nla_decoders,
			      ARRAY_SIZE(fib_rule_hdr_nla_decoders), &msg);
	}
}