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