This source file includes following definitions.
- perf_ns__name
- namespaces__new
- namespaces__free
- nsinfo__init
- nsinfo__new
- nsinfo__copy
- nsinfo__delete
- nsinfo__get
- nsinfo__put
- nsinfo__mountns_enter
- nsinfo__mountns_exit
- nsinfo__realpath
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7 #include "namespaces.h"
8 #include "event.h"
9 #include "get_current_dir_name.h"
10 #include <sys/types.h>
11 #include <sys/stat.h>
12 #include <fcntl.h>
13 #include <limits.h>
14 #include <sched.h>
15 #include <stdlib.h>
16 #include <stdio.h>
17 #include <string.h>
18 #include <unistd.h>
19 #include <asm/bug.h>
20 #include <linux/kernel.h>
21 #include <linux/zalloc.h>
22
23 static const char *perf_ns__names[] = {
24 [NET_NS_INDEX] = "net",
25 [UTS_NS_INDEX] = "uts",
26 [IPC_NS_INDEX] = "ipc",
27 [PID_NS_INDEX] = "pid",
28 [USER_NS_INDEX] = "user",
29 [MNT_NS_INDEX] = "mnt",
30 [CGROUP_NS_INDEX] = "cgroup",
31 };
32
33 const char *perf_ns__name(unsigned int id)
34 {
35 if (id >= ARRAY_SIZE(perf_ns__names))
36 return "UNKNOWN";
37 return perf_ns__names[id];
38 }
39
40 struct namespaces *namespaces__new(struct perf_record_namespaces *event)
41 {
42 struct namespaces *namespaces;
43 u64 link_info_size = ((event ? event->nr_namespaces : NR_NAMESPACES) *
44 sizeof(struct perf_ns_link_info));
45
46 namespaces = zalloc(sizeof(struct namespaces) + link_info_size);
47 if (!namespaces)
48 return NULL;
49
50 namespaces->end_time = -1;
51
52 if (event)
53 memcpy(namespaces->link_info, event->link_info, link_info_size);
54
55 return namespaces;
56 }
57
58 void namespaces__free(struct namespaces *namespaces)
59 {
60 free(namespaces);
61 }
62
63 int nsinfo__init(struct nsinfo *nsi)
64 {
65 char oldns[PATH_MAX];
66 char spath[PATH_MAX];
67 char *newns = NULL;
68 char *statln = NULL;
69 struct stat old_stat;
70 struct stat new_stat;
71 FILE *f = NULL;
72 size_t linesz = 0;
73 int rv = -1;
74
75 if (snprintf(oldns, PATH_MAX, "/proc/self/ns/mnt") >= PATH_MAX)
76 return rv;
77
78 if (asprintf(&newns, "/proc/%d/ns/mnt", nsi->pid) == -1)
79 return rv;
80
81 if (stat(oldns, &old_stat) < 0)
82 goto out;
83
84 if (stat(newns, &new_stat) < 0)
85 goto out;
86
87
88
89
90 if (old_stat.st_ino != new_stat.st_ino) {
91 nsi->need_setns = true;
92 nsi->mntns_path = newns;
93 newns = NULL;
94 }
95
96
97
98
99 if (snprintf(spath, PATH_MAX, "/proc/%d/status", nsi->pid) >= PATH_MAX)
100 goto out;
101
102 f = fopen(spath, "r");
103 if (f == NULL)
104 goto out;
105
106 while (getline(&statln, &linesz, f) != -1) {
107
108 if (strstr(statln, "Tgid:") != NULL) {
109 nsi->tgid = (pid_t)strtol(strrchr(statln, '\t'),
110 NULL, 10);
111 nsi->nstgid = nsi->tgid;
112 }
113
114 if (strstr(statln, "NStgid:") != NULL) {
115 nsi->nstgid = (pid_t)strtol(strrchr(statln, '\t'),
116 NULL, 10);
117 break;
118 }
119 }
120 rv = 0;
121
122 out:
123 if (f != NULL)
124 (void) fclose(f);
125 free(statln);
126 free(newns);
127 return rv;
128 }
129
130 struct nsinfo *nsinfo__new(pid_t pid)
131 {
132 struct nsinfo *nsi;
133
134 if (pid == 0)
135 return NULL;
136
137 nsi = calloc(1, sizeof(*nsi));
138 if (nsi != NULL) {
139 nsi->pid = pid;
140 nsi->tgid = pid;
141 nsi->nstgid = pid;
142 nsi->need_setns = false;
143
144
145
146
147 if (nsinfo__init(nsi) == -1)
148 nsi->need_setns = false;
149
150 refcount_set(&nsi->refcnt, 1);
151 }
152
153 return nsi;
154 }
155
156 struct nsinfo *nsinfo__copy(struct nsinfo *nsi)
157 {
158 struct nsinfo *nnsi;
159
160 if (nsi == NULL)
161 return NULL;
162
163 nnsi = calloc(1, sizeof(*nnsi));
164 if (nnsi != NULL) {
165 nnsi->pid = nsi->pid;
166 nnsi->tgid = nsi->tgid;
167 nnsi->nstgid = nsi->nstgid;
168 nnsi->need_setns = nsi->need_setns;
169 if (nsi->mntns_path) {
170 nnsi->mntns_path = strdup(nsi->mntns_path);
171 if (!nnsi->mntns_path) {
172 free(nnsi);
173 return NULL;
174 }
175 }
176 refcount_set(&nnsi->refcnt, 1);
177 }
178
179 return nnsi;
180 }
181
182 void nsinfo__delete(struct nsinfo *nsi)
183 {
184 zfree(&nsi->mntns_path);
185 free(nsi);
186 }
187
188 struct nsinfo *nsinfo__get(struct nsinfo *nsi)
189 {
190 if (nsi)
191 refcount_inc(&nsi->refcnt);
192 return nsi;
193 }
194
195 void nsinfo__put(struct nsinfo *nsi)
196 {
197 if (nsi && refcount_dec_and_test(&nsi->refcnt))
198 nsinfo__delete(nsi);
199 }
200
201 void nsinfo__mountns_enter(struct nsinfo *nsi,
202 struct nscookie *nc)
203 {
204 char curpath[PATH_MAX];
205 int oldns = -1;
206 int newns = -1;
207 char *oldcwd = NULL;
208
209 if (nc == NULL)
210 return;
211
212 nc->oldns = -1;
213 nc->newns = -1;
214
215 if (!nsi || !nsi->need_setns)
216 return;
217
218 if (snprintf(curpath, PATH_MAX, "/proc/self/ns/mnt") >= PATH_MAX)
219 return;
220
221 oldcwd = get_current_dir_name();
222 if (!oldcwd)
223 return;
224
225 oldns = open(curpath, O_RDONLY);
226 if (oldns < 0)
227 goto errout;
228
229 newns = open(nsi->mntns_path, O_RDONLY);
230 if (newns < 0)
231 goto errout;
232
233 if (setns(newns, CLONE_NEWNS) < 0)
234 goto errout;
235
236 nc->oldcwd = oldcwd;
237 nc->oldns = oldns;
238 nc->newns = newns;
239 return;
240
241 errout:
242 free(oldcwd);
243 if (oldns > -1)
244 close(oldns);
245 if (newns > -1)
246 close(newns);
247 }
248
249 void nsinfo__mountns_exit(struct nscookie *nc)
250 {
251 if (nc == NULL || nc->oldns == -1 || nc->newns == -1 || !nc->oldcwd)
252 return;
253
254 setns(nc->oldns, CLONE_NEWNS);
255
256 if (nc->oldcwd) {
257 WARN_ON_ONCE(chdir(nc->oldcwd));
258 zfree(&nc->oldcwd);
259 }
260
261 if (nc->oldns > -1) {
262 close(nc->oldns);
263 nc->oldns = -1;
264 }
265
266 if (nc->newns > -1) {
267 close(nc->newns);
268 nc->newns = -1;
269 }
270 }
271
272 char *nsinfo__realpath(const char *path, struct nsinfo *nsi)
273 {
274 char *rpath;
275 struct nscookie nsc;
276
277 nsinfo__mountns_enter(nsi, &nsc);
278 rpath = realpath(path, NULL);
279 nsinfo__mountns_exit(&nsc);
280
281 return rpath;
282 }