Commit | Line | Data |
---|---|---|
0e28eb33 MJ |
1 | /* |
2 | * Copyright (C) 2019 Michael Jeanson <mjeanson@efficios.com> | |
3 | * | |
4 | * This library is free software; you can redistribute it and/or modify it | |
5 | * under the terms of the GNU Lesser General Public License as published by the | |
6 | * Free Software Foundation; version 2.1 of the License. | |
7 | * | |
8 | * This library is distributed in the hope that it will be useful, but WITHOUT | |
9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License | |
11 | * for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU Lesser General Public License | |
14 | * along with this library; if not, write to the Free Software Foundation, | |
15 | * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
16 | */ | |
17 | ||
18 | #ifndef _GNU_SOURCE | |
19 | #define _GNU_SOURCE | |
20 | #endif | |
21 | ||
22 | #include <popt.h> | |
23 | #include <sched.h> | |
24 | #include <stdio.h> | |
25 | #include <stdlib.h> | |
26 | #include <sys/stat.h> | |
27 | #include <sys/types.h> | |
28 | #include <unistd.h> | |
29 | #include <stdarg.h> | |
30 | #include <string.h> | |
31 | ||
32 | #include <common/compat/tid.h> | |
33 | ||
34 | #include "utils.h" | |
35 | #include "signal-helper.h" | |
36 | ||
37 | #define LTTNG_PROC_NS_PATH_MAX 40 | |
38 | ||
39 | static int debug = 0; | |
40 | static char *ns_opt = NULL; | |
41 | static char *before_unshare_wait_file_path = NULL; | |
42 | static char *after_unshare_wait_file_path = NULL; | |
43 | static char *after_unshare_signal_file_path = NULL; | |
44 | ||
45 | static | |
46 | struct poptOption opts[] = { | |
47 | /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */ | |
48 | { "debug", 'd', POPT_ARG_NONE, &debug, 0, "Enable debug output", NULL }, | |
49 | { "ns", 'n', POPT_ARG_STRING, &ns_opt, 0, "Namespace short identifier", NULL }, | |
50 | { "before", 'b', POPT_ARG_STRING, &before_unshare_wait_file_path, 0, "Wait for file before unshare", NULL }, | |
51 | { "after", 'a', POPT_ARG_STRING, &after_unshare_wait_file_path, 0, "Wait for file after unshare", NULL }, | |
52 | { "signal", 's', POPT_ARG_STRING, &after_unshare_signal_file_path, 0, "Create signal file after unshare", NULL }, | |
53 | POPT_AUTOHELP | |
54 | { NULL, 0, 0, NULL, 0 } | |
55 | }; | |
56 | ||
57 | static | |
58 | void debug_printf(const char *format, ...) { | |
59 | va_list args; | |
60 | va_start(args, format); | |
61 | ||
62 | if (debug) | |
63 | vfprintf(stderr, format, args); | |
64 | ||
65 | va_end(args); | |
66 | } | |
67 | ||
68 | static | |
69 | ino_t get_ns_inum(char ns[]) { | |
70 | struct stat sb; | |
71 | char proc_ns_path[LTTNG_PROC_NS_PATH_MAX]; | |
72 | ||
73 | /* | |
74 | * /proc/thread-self was introduced in kernel v3.17 | |
75 | */ | |
76 | if (snprintf(proc_ns_path, LTTNG_PROC_NS_PATH_MAX, | |
77 | "/proc/thread-self/ns/%s", ns) >= 0) { | |
78 | if (stat(proc_ns_path, &sb) == 0) { | |
79 | return sb.st_ino; | |
80 | } | |
81 | } | |
82 | ||
83 | if (snprintf(proc_ns_path, LTTNG_PROC_NS_PATH_MAX, | |
84 | "/proc/self/task/%d/%s/net", | |
85 | gettid(), ns) >= 0) { | |
86 | ||
87 | if (stat(proc_ns_path, &sb) == 0) { | |
88 | return sb.st_ino; | |
89 | } | |
90 | } | |
91 | ||
92 | return 1; | |
93 | } | |
94 | ||
95 | static | |
96 | int do_the_needful(int ns_flag, char ns_str[]) { | |
97 | int ret = 0; | |
98 | ino_t ns1, ns2; | |
99 | ||
100 | ns1 = get_ns_inum(ns_str); | |
101 | debug_printf("Initial %s ns inode number: %lu\n", ns_str, ns1); | |
102 | ||
103 | /* | |
104 | * Wait on synchronization before unshare | |
105 | */ | |
106 | if (before_unshare_wait_file_path) { | |
107 | ret = wait_on_file(before_unshare_wait_file_path); | |
108 | if (ret != 0) { | |
109 | goto end; | |
110 | } | |
111 | } | |
112 | ||
113 | ret = unshare(ns_flag); | |
114 | ||
115 | if (ret == -1) { | |
116 | perror("unshare"); | |
117 | ret = 0; | |
118 | } | |
119 | ||
120 | ns2 = get_ns_inum(ns_str); | |
121 | debug_printf("Post unshare %s ns inode number: %lu\n", ns_str, ns2); | |
122 | ||
123 | /* | |
124 | * Signal that the unshare call is completed. | |
125 | */ | |
126 | if (after_unshare_signal_file_path) { | |
127 | ret = create_file(after_unshare_signal_file_path); | |
128 | ||
129 | if (ret != 0) { | |
130 | goto end; | |
131 | } | |
132 | } | |
133 | ||
134 | /* | |
135 | * Wait on synchronization after unshare | |
136 | */ | |
137 | if (after_unshare_wait_file_path) { | |
138 | ret = wait_on_file(after_unshare_wait_file_path); | |
139 | if (ret != 0) { | |
140 | goto end; | |
141 | } | |
142 | } | |
143 | ||
144 | end: | |
145 | return ret; | |
146 | } | |
147 | ||
148 | int main(int argc, const char **argv) { | |
149 | int opt; | |
150 | int ret = EXIT_SUCCESS; | |
151 | poptContext pc; | |
152 | ||
153 | pc = poptGetContext(NULL, argc, argv, opts, 0); | |
154 | poptReadDefaultConfig(pc, 0); | |
155 | ||
156 | if (argc < 2) { | |
157 | poptPrintHelp(pc, stderr, 0); | |
158 | ret = EXIT_FAILURE; | |
159 | goto end; | |
160 | } | |
161 | ||
162 | while ((opt = poptGetNextOpt(pc)) >= 0) { | |
163 | switch(opt) { | |
164 | default: | |
165 | poptPrintUsage(pc, stderr, 0); | |
166 | ret = EXIT_FAILURE; | |
167 | goto end; | |
168 | } | |
169 | } | |
170 | ||
171 | if (opt < -1) { | |
172 | /* an error occurred during option processing */ | |
173 | poptPrintUsage(pc, stderr, 0); | |
174 | fprintf(stderr, "%s: %s\n", | |
175 | poptBadOption(pc, POPT_BADOPTION_NOALIAS), | |
176 | poptStrerror(opt)); | |
177 | ret = EXIT_FAILURE; | |
178 | goto end; | |
179 | } | |
180 | ||
181 | if (ns_opt == NULL) { | |
182 | poptPrintUsage(pc, stderr, 0); | |
183 | ret = EXIT_FAILURE; | |
184 | goto end; | |
185 | } | |
186 | ||
187 | if (set_signal_handler()) { | |
188 | ret = EXIT_FAILURE; | |
189 | goto end; | |
190 | } | |
191 | ||
192 | if (strncmp(ns_opt, "cgroup", 3) == 0) { | |
193 | do_the_needful(CLONE_NEWCGROUP, "cgroup"); | |
194 | } else if (strncmp(ns_opt, "ipc", 3) == 0) { | |
195 | do_the_needful(CLONE_NEWIPC, "ipc"); | |
196 | } else if (strncmp(ns_opt, "mnt", 3) == 0) { | |
197 | do_the_needful(CLONE_NEWNS, "mnt"); | |
198 | } else if (strncmp(ns_opt, "net", 3) == 0) { | |
199 | do_the_needful(CLONE_NEWNET, "net"); | |
200 | } else if (strncmp(ns_opt, "pid", 3) == 0) { | |
201 | do_the_needful(CLONE_NEWPID, "pid"); | |
202 | } else if (strncmp(ns_opt, "user", 3) == 0) { | |
203 | // Will always fail, requires a single threaded application, which can't happen with UST. | |
204 | do_the_needful(CLONE_NEWUSER, "user"); | |
205 | } else if (strncmp(ns_opt, "uts", 3) == 0) { | |
206 | do_the_needful(CLONE_NEWUTS, "uts"); | |
207 | } else { | |
208 | printf("invalid ns id\n"); | |
209 | ret = EXIT_FAILURE; | |
210 | } | |
211 | ||
212 | end: | |
213 | poptFreeContext(pc); | |
214 | return ret; | |
215 | } |