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Commit | Line | Data |
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1dafceb1 DA |
1 | /* |
2 | * fs.c filesystem APIs | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation; either version | |
7 | * 2 of the License, or (at your option) any later version. | |
8 | * | |
9 | * Authors: David Ahern <dsa@cumulusnetworks.com> | |
10 | * | |
11 | */ | |
12 | ||
13 | #include <sys/types.h> | |
14 | #include <sys/stat.h> | |
15 | #include <sys/socket.h> | |
16 | #include <sys/mount.h> | |
f443565f | 17 | #include <ctype.h> |
1dafceb1 DA |
18 | #include <fcntl.h> |
19 | #include <stdio.h> | |
20 | #include <stdlib.h> | |
21 | #include <unistd.h> | |
22 | #include <string.h> | |
23 | #include <errno.h> | |
24 | #include <limits.h> | |
25 | ||
26 | #include "utils.h" | |
27 | ||
28 | #define CGROUP2_FS_NAME "cgroup2" | |
29 | ||
30 | /* if not already mounted cgroup2 is mounted here for iproute2's use */ | |
31 | #define MNT_CGRP2_PATH "/var/run/cgroup2" | |
32 | ||
33 | /* return mount path of first occurrence of given fstype */ | |
34 | static char *find_fs_mount(const char *fs_to_find) | |
35 | { | |
36 | char path[4096]; | |
37 | char fstype[128]; /* max length of any filesystem name */ | |
38 | char *mnt = NULL; | |
39 | FILE *fp; | |
40 | ||
41 | fp = fopen("/proc/mounts", "r"); | |
42 | if (!fp) { | |
43 | fprintf(stderr, | |
44 | "Failed to open mounts file: %s\n", strerror(errno)); | |
45 | return NULL; | |
46 | } | |
47 | ||
eab45078 | 48 | while (fscanf(fp, "%*s %4095s %127s %*s %*d %*d\n", |
1dafceb1 DA |
49 | path, fstype) == 2) { |
50 | if (strcmp(fstype, fs_to_find) == 0) { | |
51 | mnt = strdup(path); | |
52 | break; | |
53 | } | |
54 | } | |
55 | ||
56 | fclose(fp); | |
57 | ||
58 | return mnt; | |
59 | } | |
60 | ||
61 | /* caller needs to free string returned */ | |
62 | char *find_cgroup2_mount(void) | |
63 | { | |
64 | char *mnt = find_fs_mount(CGROUP2_FS_NAME); | |
65 | ||
66 | if (mnt) | |
67 | return mnt; | |
68 | ||
69 | mnt = strdup(MNT_CGRP2_PATH); | |
70 | if (!mnt) { | |
71 | fprintf(stderr, "Failed to allocate memory for cgroup2 path\n"); | |
72 | return NULL; | |
73 | ||
74 | } | |
75 | ||
76 | if (make_path(mnt, 0755)) { | |
77 | fprintf(stderr, "Failed to setup vrf cgroup2 directory\n"); | |
78 | free(mnt); | |
79 | return NULL; | |
80 | } | |
81 | ||
82 | if (mount("none", mnt, CGROUP2_FS_NAME, 0, NULL)) { | |
83 | /* EBUSY means already mounted */ | |
2bbc5b07 DA |
84 | if (errno == EBUSY) |
85 | goto out; | |
86 | ||
87 | if (errno == ENODEV) { | |
1dafceb1 DA |
88 | fprintf(stderr, |
89 | "Failed to mount cgroup2. Are CGROUPS enabled in your kernel?\n"); | |
2bbc5b07 DA |
90 | } else { |
91 | fprintf(stderr, | |
92 | "Failed to mount cgroup2: %s\n", | |
93 | strerror(errno)); | |
1dafceb1 | 94 | } |
2bbc5b07 DA |
95 | free(mnt); |
96 | return NULL; | |
1dafceb1 | 97 | } |
2bbc5b07 | 98 | out: |
1dafceb1 DA |
99 | return mnt; |
100 | } | |
101 | ||
102 | int make_path(const char *path, mode_t mode) | |
103 | { | |
104 | char *dir, *delim; | |
1dafceb1 DA |
105 | int rc = -1; |
106 | ||
107 | delim = dir = strdup(path); | |
108 | if (dir == NULL) { | |
109 | fprintf(stderr, "strdup failed copying path"); | |
110 | return -1; | |
111 | } | |
112 | ||
113 | /* skip '/' -- it had better exist */ | |
114 | if (*delim == '/') | |
115 | delim++; | |
116 | ||
117 | while (1) { | |
118 | delim = strchr(delim, '/'); | |
119 | if (delim) | |
120 | *delim = '\0'; | |
121 | ||
ac3415f5 PS |
122 | rc = mkdir(dir, mode); |
123 | if (mkdir(dir, mode) != 0 && errno != EEXIST) { | |
124 | fprintf(stderr, "mkdir failed for %s: %s\n", | |
125 | dir, strerror(errno)); | |
126 | goto out; | |
1dafceb1 DA |
127 | } |
128 | ||
129 | if (delim == NULL) | |
130 | break; | |
131 | ||
132 | *delim = '/'; | |
133 | delim++; | |
134 | if (*delim == '\0') | |
135 | break; | |
136 | } | |
137 | rc = 0; | |
138 | out: | |
139 | free(dir); | |
140 | ||
141 | return rc; | |
142 | } | |
f443565f DA |
143 | |
144 | int get_command_name(const char *pid, char *comm, size_t len) | |
145 | { | |
146 | char path[PATH_MAX]; | |
147 | char line[128]; | |
148 | FILE *fp; | |
149 | ||
150 | if (snprintf(path, sizeof(path), | |
151 | "/proc/%s/status", pid) >= sizeof(path)) { | |
152 | return -1; | |
153 | } | |
154 | ||
155 | fp = fopen(path, "r"); | |
156 | if (!fp) | |
157 | return -1; | |
158 | ||
159 | comm[0] = '\0'; | |
160 | while (fgets(line, sizeof(line), fp)) { | |
161 | char *nl, *name; | |
162 | ||
163 | name = strstr(line, "Name:"); | |
164 | if (!name) | |
165 | continue; | |
166 | ||
167 | name += 5; | |
168 | while (isspace(*name)) | |
169 | name++; | |
170 | ||
171 | nl = strchr(name, '\n'); | |
172 | if (nl) | |
173 | *nl = '\0'; | |
174 | ||
18f156bf | 175 | strlcpy(comm, name, len); |
f443565f DA |
176 | break; |
177 | } | |
178 | ||
179 | fclose(fp); | |
180 | ||
181 | return 0; | |
182 | } |