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1 | /* | |
2 | * lxc: linux Container library | |
3 | * | |
4 | * (C) Copyright IBM Corp. 2007, 2008 | |
5 | * | |
6 | * Authors: | |
7 | * Daniel Lezcano <dlezcano at fr.ibm.com> | |
8 | * | |
9 | * This library is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU Lesser General Public | |
11 | * License as published by the Free Software Foundation; either | |
12 | * version 2.1 of the License, or (at your option) any later version. | |
13 | * | |
14 | * This library is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
17 | * Lesser General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU Lesser General Public | |
20 | * License along with this library; if not, write to the Free Software | |
21 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
22 | */ | |
23 | ||
24 | #define _GNU_SOURCE | |
25 | #include <stdio.h> | |
26 | #undef _GNU_SOURCE | |
27 | #include <string.h> | |
28 | #include <stdlib.h> | |
29 | #include <dirent.h> | |
30 | #include <errno.h> | |
31 | #include <unistd.h> | |
32 | #include <signal.h> | |
33 | #include <sys/param.h> | |
34 | #include <sys/file.h> | |
35 | #include <sys/mount.h> | |
36 | #include <sys/types.h> | |
37 | #include <sys/prctl.h> | |
38 | #include <sys/capability.h> | |
39 | #include <sys/wait.h> | |
40 | ||
41 | #include <lxc/lxc.h> | |
42 | ||
43 | LXC_TTY_HANDLER(SIGINT); | |
44 | LXC_TTY_HANDLER(SIGQUIT); | |
45 | ||
46 | int lxc_start(const char *name, char *argv[]) | |
47 | { | |
48 | char init[MAXPATHLEN]; | |
49 | char *val = NULL; | |
50 | char ttyname[MAXPATHLEN]; | |
51 | int fd, lock, sv[2], sync = 0, err = -1; | |
52 | pid_t pid; | |
53 | int clone_flags; | |
54 | ||
55 | lock = lxc_get_lock(name); | |
56 | if (!lock) { | |
57 | lxc_log_error("'%s' is busy", name); | |
58 | return -1; | |
59 | } | |
60 | ||
61 | if (lock < 0) { | |
62 | lxc_log_error("failed to acquire lock on '%s':%s", | |
63 | name, strerror(-lock)); | |
64 | return -1; | |
65 | } | |
66 | ||
67 | /* Begin the set the state to STARTING*/ | |
68 | if (lxc_setstate(name, STARTING)) { | |
69 | lxc_log_error("failed to set state %s", lxc_state2str(STARTING)); | |
70 | goto out; | |
71 | } | |
72 | ||
73 | if (readlink("/proc/self/fd/0", ttyname, sizeof(ttyname)) < 0) { | |
74 | lxc_log_syserror("failed to read '/proc/self/fd/0'"); | |
75 | goto out; | |
76 | } | |
77 | ||
78 | ||
79 | /* Synchro socketpair */ | |
80 | if (socketpair(AF_LOCAL, SOCK_STREAM, 0, sv)) { | |
81 | lxc_log_syserror("failed to create communication socketpair"); | |
82 | goto out; | |
83 | } | |
84 | ||
85 | /* Avoid signals from terminal */ | |
86 | LXC_TTY_ADD_HANDLER(SIGINT); | |
87 | LXC_TTY_ADD_HANDLER(SIGQUIT); | |
88 | ||
89 | clone_flags = CLONE_NEWPID|CLONE_NEWIPC|CLONE_NEWNS; | |
90 | if (conf_has_utsname(name)) | |
91 | clone_flags |= CLONE_NEWUTS; | |
92 | if (conf_has_network(name)) | |
93 | clone_flags |= CLONE_NEWNET; | |
94 | ||
95 | /* Create a process in a new set of namespaces */ | |
96 | pid = fork_ns(clone_flags); | |
97 | if (pid < 0) { | |
98 | lxc_log_syserror("failed to fork into a new namespace"); | |
99 | goto err_fork_ns; | |
100 | } | |
101 | ||
102 | if (!pid) { | |
103 | ||
104 | close(sv[1]); | |
105 | ||
106 | /* Be sure we don't inherit this after the exec */ | |
107 | fcntl(sv[0], F_SETFD, FD_CLOEXEC); | |
108 | ||
109 | /* Tell our father he can begin to configure the container */ | |
110 | if (write(sv[0], &sync, sizeof(sync)) < 0) { | |
111 | lxc_log_syserror("failed to write socket"); | |
112 | goto out_child; | |
113 | } | |
114 | ||
115 | /* Wait for the father to finish the configuration */ | |
116 | if (read(sv[0], &sync, sizeof(sync)) < 0) { | |
117 | lxc_log_syserror("failed to read socket"); | |
118 | goto out_child; | |
119 | } | |
120 | ||
121 | /* Setup the container, ip, names, utsname, ... */ | |
122 | if (lxc_setup(name)) { | |
123 | lxc_log_error("failed to setup the container"); | |
124 | if (write(sv[0], &sync, sizeof(sync)) < 0) | |
125 | lxc_log_syserror("failed to write the socket"); | |
126 | goto out_child; | |
127 | } | |
128 | ||
129 | if (mount(ttyname, "/dev/console", "none", MS_BIND, 0)) { | |
130 | lxc_log_syserror("failed to mount '/dev/console'"); | |
131 | goto out_child; | |
132 | } | |
133 | ||
134 | if (prctl(PR_CAPBSET_DROP, CAP_SYS_BOOT, 0, 0, 0)) { | |
135 | lxc_log_syserror("failed to remove CAP_SYS_BOOT capability"); | |
136 | goto out_child; | |
137 | } | |
138 | ||
139 | execvp(argv[0], argv); | |
140 | lxc_log_syserror("failed to exec %s", argv[0]); | |
141 | ||
142 | /* If the exec fails, tell that to our father */ | |
143 | if (write(sv[0], &sync, sizeof(sync)) < 0) | |
144 | lxc_log_syserror("failed to write the socket"); | |
145 | ||
146 | out_child: | |
147 | exit(1); | |
148 | } | |
149 | ||
150 | close(sv[0]); | |
151 | ||
152 | /* Wait for the child to be ready */ | |
153 | if (read(sv[1], &sync, sizeof(sync)) < 0) { | |
154 | lxc_log_syserror("failed to read the socket"); | |
155 | goto err_pipe_read; | |
156 | } | |
157 | ||
158 | if (lxc_link_nsgroup(name, pid)) | |
159 | lxc_log_warning("cgroupfs not found: cgroup disabled"); | |
160 | ||
161 | /* Create the network configuration */ | |
162 | if (clone_flags & CLONE_NEWNET && conf_create_network(name, pid)) { | |
163 | lxc_log_error("failed to create the configured network"); | |
164 | goto err_create_network; | |
165 | } | |
166 | ||
167 | /* Tell the child to continue its initialization */ | |
168 | if (write(sv[1], &sync, sizeof(sync)) < 0) { | |
169 | lxc_log_syserror("failed to write the socket"); | |
170 | goto err_pipe_write; | |
171 | } | |
172 | ||
173 | /* Wait for the child to exec or returning an error */ | |
174 | err = read(sv[1], &sync, sizeof(sync)); | |
175 | if (err < 0) { | |
176 | lxc_log_error("failed to read the socket"); | |
177 | goto err_pipe_read2; | |
178 | } | |
179 | ||
180 | if (err > 0) { | |
181 | lxc_log_error("something went wrong with %d", pid); | |
182 | /* TODO : check status etc ... */ | |
183 | waitpid(pid, NULL, 0); | |
184 | goto err_child_failed; | |
185 | } | |
186 | ||
187 | asprintf(&val, "%d\n", pid); | |
188 | ||
189 | snprintf(init, MAXPATHLEN, LXCPATH "/%s/init", name); | |
190 | ||
191 | fd = open(init, O_WRONLY|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR); | |
192 | if (fd < 0) { | |
193 | lxc_log_syserror("failed to open '%s'", init); | |
194 | goto err_write; | |
195 | } | |
196 | ||
197 | if (write(fd, val, strlen(val)) < 0) { | |
198 | lxc_log_syserror("failed to write the init pid"); | |
199 | goto err_write; | |
200 | } | |
201 | ||
202 | close(fd); | |
203 | ||
204 | if (lxc_setstate(name, RUNNING)) { | |
205 | lxc_log_error("failed to set state to %s", | |
206 | lxc_state2str(RUNNING)); | |
207 | goto err_state_failed; | |
208 | } | |
209 | ||
210 | wait_again: | |
211 | if (waitpid(pid, NULL, 0) < 0) { | |
212 | if (errno == EINTR) | |
213 | goto wait_again; | |
214 | lxc_log_syserror("failed to wait the pid %d", pid); | |
215 | goto err_waitpid_failed; | |
216 | } | |
217 | ||
218 | if (lxc_setstate(name, STOPPING)) | |
219 | lxc_log_error("failed to set state %s", lxc_state2str(STOPPING)); | |
220 | ||
221 | #ifdef NETWORK_DESTROY | |
222 | if (clone_flags & CLONE_NEWNET && conf_destroy_network(name)) | |
223 | lxc_log_error("failed to destroy the network"); | |
224 | #endif | |
225 | ||
226 | err = 0; | |
227 | out: | |
228 | if (lxc_setstate(name, STOPPED)) | |
229 | lxc_log_error("failed to set state %s", lxc_state2str(STOPPED)); | |
230 | ||
231 | lxc_unlink_nsgroup(name); | |
232 | unlink(init); | |
233 | free(val); | |
234 | lxc_put_lock(lock); | |
235 | LXC_TTY_DEL_HANDLER(SIGQUIT); | |
236 | LXC_TTY_DEL_HANDLER(SIGINT); | |
237 | ||
238 | return err; | |
239 | ||
240 | err_write: | |
241 | close(fd); | |
242 | ||
243 | err_state_failed: | |
244 | err_child_failed: | |
245 | err_pipe_read2: | |
246 | err_pipe_write: | |
247 | #ifdef NETWORK_DESTROY | |
248 | if (clone_flags & CLONE_NEWNET) | |
249 | conf_destroy_network(name); | |
250 | #endif | |
251 | err_create_network: | |
252 | err_pipe_read: | |
253 | err_waitpid_failed: | |
254 | if (lxc_setstate(name, ABORTING)) | |
255 | lxc_log_error("failed to set state %s", lxc_state2str(STOPPED)); | |
256 | ||
257 | kill(pid, SIGKILL); | |
258 | err_fork_ns: | |
259 | close(sv[0]); | |
260 | close(sv[1]); | |
261 | goto out; | |
262 | } |