File: proc.cpp

package info (click to toggle)
dnf5 5.4.0.0-1
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid
  • size: 17,960 kB
  • sloc: cpp: 94,312; python: 3,370; xml: 1,073; ruby: 600; sql: 250; ansic: 232; sh: 104; perl: 62; makefile: 30
file content (142 lines) | stat: -rw-r--r-- 4,089 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
// Copyright Contributors to the DNF5 project.
// Copyright Contributors to the libdnf project.
// SPDX-License-Identifier: LGPL-2.1-or-later
//
// This file is part of libdnf: https://github.com/rpm-software-management/libdnf/
//
// Libdnf 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.
//
// Libdnf 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 libdnf.  If not, see <https://www.gnu.org/licenses/>.

#include "libdnf5/common/proc.hpp"

#include "libdnf5/common/exception.hpp"
#include "libdnf5/utils/bgettext/bgettext-mark-domain.h"

#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <fmt/format.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

#include <algorithm>
#include <cstdlib>
#include <fstream>
#include <string>
#include <vector>

namespace libdnf5 {

uid_t read_login_uid_from_proc(pid_t pid) noexcept {
    auto in = open(fmt::format("/proc/{}/loginuid", pid).c_str(), O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
    if (in == -1) {
        return INVALID_UID;
    }

    ssize_t len;
    char buf[16];
    do {
        errno = 0;
        len = read(in, buf, sizeof(buf) - 1);
    } while (len < 0 && errno == EINTR);

    close(in);

    if (len <= 0) {
        return INVALID_UID;
    }

    buf[len] = '\0';
    char * endptr;
    errno = 0;
    auto uid = static_cast<uid_t>(strtol(buf, &endptr, 10));
    if (buf == endptr || errno != 0) {
        return INVALID_UID;
    }

    return uid;
}

uid_t get_login_uid() noexcept {
    static uid_t cached_uid = libdnf5::INVALID_UID;
    if (cached_uid == libdnf5::INVALID_UID) {
        cached_uid = libdnf5::read_login_uid_from_proc(getpid());
        if (cached_uid == libdnf5::INVALID_UID) {
            cached_uid = getuid();
        }
    }
    return cached_uid;
}

std::set<pid_t> fuser(const std::filesystem::path & path) {
    std::set<pid_t> pids;
    std::error_code ec;

    struct stat target_st;
    if (stat(path.c_str(), &target_st) == -1) {
        throw libdnf5::SystemError{errno, M_("Cannot stat {}"), path.string()};
    }

    for (const auto & entry : std::filesystem::directory_iterator{"/proc", ec}) {
        if (ec) {
            continue;
        }

        const std::string & entry_name = entry.path().filename().string();
        if (!entry.is_directory(ec) || !std::all_of(entry_name.begin(), entry_name.end(), isdigit)) {
            continue;
        }
        const pid_t pid = std::stoi(entry_name);

        const std::filesystem::path fd_dir_path = entry.path() / "fd";
        for (const auto & fd_entry : std::filesystem::directory_iterator{fd_dir_path, ec}) {
            if (ec) {
                continue;
            }
            struct stat fd_st;
            if (stat(fd_entry.path().c_str(), &fd_st) != -1) {
                if (fd_st.st_dev == target_st.st_dev && fd_st.st_ino == target_st.st_ino) {
                    pids.insert(pid);
                    break;
                }
            }
        }
    }

    return pids;
}

std::vector<std::string> pid_cmdline(const pid_t pid) {
    const std::filesystem::path path{libdnf5::utils::sformat("/proc/{}/cmdline", pid)};
    std::ifstream stream{path, std::ios::binary};
    if (!stream.is_open()) {
        throw libdnf5::SystemError{errno, M_("Cannot open {}"), path.string()};
    }

    std::vector<std::string> args;
    std::string current;
    char c;
    while (stream.get(c)) {
        if (c == '\0') {
            args.push_back(current);
            current = "";
        } else {
            current += c;
        }
    }
    args.push_back(current);
    return args;
}

}  // namespace libdnf5