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1479465f GJ |
1 | /* |
2 | * libdpkg - Debian packaging suite library routines | |
3 | * subproc.c - subprocess helper routines | |
4 | * | |
5 | * Copyright © 1995 Ian Jackson <ijackson@chiark.greenend.org.uk> | |
6 | * Copyright © 2008-2014 Guillem Jover <guillem@debian.org> | |
7 | * | |
8 | * This is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation; either version 2 of the License, or | |
11 | * (at your option) any later version. | |
12 | * | |
13 | * This is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License | |
19 | * along with this program. If not, see <https://www.gnu.org/licenses/>. | |
20 | */ | |
21 | ||
22 | #include <config.h> | |
23 | #include <compat.h> | |
24 | ||
25 | #include <sys/types.h> | |
26 | #include <sys/wait.h> | |
27 | ||
28 | #include <errno.h> | |
29 | #include <string.h> | |
30 | #include <signal.h> | |
31 | #include <unistd.h> | |
32 | #include <stdlib.h> | |
33 | #include <stdio.h> | |
34 | ||
35 | #include <dpkg/i18n.h> | |
36 | #include <dpkg/dpkg.h> | |
37 | #include <dpkg/subproc.h> | |
38 | ||
39 | static int signo_ignores[] = { SIGQUIT, SIGINT }; | |
40 | static struct sigaction sa_save[array_count(signo_ignores)]; | |
41 | ||
42 | static void | |
43 | subproc_reset_signal(int sig, struct sigaction *sa_old) | |
44 | { | |
45 | if (sigaction(sig, sa_old, NULL)) { | |
46 | fprintf(stderr, _("error un-catching signal %s: %s\n"), | |
47 | strsignal(sig), strerror(errno)); | |
48 | onerr_abort++; | |
49 | } | |
50 | } | |
51 | ||
52 | static void | |
53 | subproc_set_signal(int sig, struct sigaction *sa, struct sigaction *sa_old, | |
54 | const char *name) | |
55 | { | |
56 | if (sigaction(sig, sa, sa_old)) | |
57 | ohshite(_("unable to ignore signal %s before running %.250s"), | |
58 | strsignal(sig), name); | |
59 | } | |
60 | ||
61 | void | |
62 | subproc_signals_ignore(const char *name) | |
63 | { | |
64 | struct sigaction sa; | |
65 | size_t i; | |
66 | ||
67 | onerr_abort++; | |
68 | memset(&sa, 0, sizeof(sa)); | |
69 | sigemptyset(&sa.sa_mask); | |
70 | sa.sa_handler = SIG_IGN; | |
71 | sa.sa_flags = 0; | |
72 | ||
73 | for (i = 0; i < array_count(signo_ignores); i++) | |
74 | subproc_set_signal(signo_ignores[i], &sa, &sa_save[i], name); | |
75 | ||
76 | push_cleanup(subproc_signals_cleanup, ~0, NULL, 0, 0); | |
77 | onerr_abort--; | |
78 | } | |
79 | ||
80 | void | |
81 | subproc_signals_cleanup(int argc, void **argv) | |
82 | { | |
83 | size_t i; | |
84 | ||
85 | for (i = 0; i < array_count(signo_ignores); i++) | |
86 | subproc_reset_signal(signo_ignores[i], &sa_save[i]); | |
87 | } | |
88 | ||
89 | void | |
90 | subproc_signals_restore(void) | |
91 | { | |
92 | pop_cleanup(ehflag_normaltidy); | |
93 | } | |
94 | ||
95 | static void | |
96 | print_subproc_error(const char *emsg, const void *data) | |
97 | { | |
98 | fprintf(stderr, _("%s (subprocess): %s\n"), dpkg_get_progname(), emsg); | |
99 | } | |
100 | ||
101 | pid_t | |
102 | subproc_fork(void) | |
103 | { | |
104 | pid_t pid; | |
105 | ||
106 | pid = fork(); | |
107 | if (pid == -1) { | |
108 | onerr_abort++; | |
109 | ohshite(_("fork failed")); | |
110 | } | |
111 | if (pid > 0) | |
112 | return pid; | |
113 | ||
114 | /* Push a new error context, so that we don't do the other cleanups, | |
115 | * because they'll be done by/in the parent process. */ | |
116 | push_error_context_func(catch_fatal_error, print_subproc_error, NULL); | |
117 | ||
118 | return pid; | |
119 | } | |
120 | ||
121 | static int | |
122 | subproc_check(int status, const char *desc, enum subproc_flags flags) | |
123 | { | |
124 | void (*out)(const char *fmt, ...) DPKG_ATTR_PRINTF(1); | |
125 | int n; | |
126 | ||
127 | if (flags & SUBPROC_WARN) | |
128 | out = warning; | |
129 | else | |
130 | out = ohshit; | |
131 | ||
132 | if (WIFEXITED(status)) { | |
133 | n = WEXITSTATUS(status); | |
134 | if (!n) | |
135 | return 0; | |
136 | if (flags & SUBPROC_RETERROR) | |
137 | return n; | |
138 | ||
139 | out(_("subprocess %s returned error exit status %d"), desc, n); | |
140 | } else if (WIFSIGNALED(status)) { | |
141 | n = WTERMSIG(status); | |
142 | if (!n) | |
143 | return 0; | |
144 | if ((flags & SUBPROC_NOPIPE) && n == SIGPIPE) | |
145 | return 0; | |
146 | if (flags & SUBPROC_RETSIGNO) | |
147 | return n; | |
148 | ||
149 | if (n == SIGINT) | |
150 | out(_("subprocess %s was interrupted"), desc); | |
151 | else | |
152 | out(_("subprocess %s was killed by signal (%s)%s"), | |
153 | desc, strsignal(n), | |
154 | WCOREDUMP(status) ? _(", core dumped") : ""); | |
155 | } else { | |
156 | if (flags & SUBPROC_RETERROR) | |
157 | return -1; | |
158 | ||
159 | out(_("subprocess %s failed with wait status code %d"), desc, | |
160 | status); | |
161 | } | |
162 | ||
163 | return -1; | |
164 | } | |
165 | ||
166 | static int | |
167 | subproc_wait(pid_t pid, const char *desc) | |
168 | { | |
169 | pid_t dead_pid; | |
170 | int status; | |
171 | ||
172 | while ((dead_pid = waitpid(pid, &status, 0)) == -1 && errno == EINTR) ; | |
173 | ||
174 | if (dead_pid != pid) { | |
175 | onerr_abort++; | |
176 | ohshite(_("wait for subprocess %s failed"), desc); | |
177 | } | |
178 | ||
179 | return status; | |
180 | } | |
181 | ||
182 | int | |
183 | subproc_reap(pid_t pid, const char *desc, enum subproc_flags flags) | |
184 | { | |
185 | int status, rc; | |
186 | ||
187 | status = subproc_wait(pid, desc); | |
188 | ||
189 | if (flags & SUBPROC_NOCHECK) | |
190 | rc = status; | |
191 | else | |
192 | rc = subproc_check(status, desc, flags); | |
193 | ||
194 | return rc; | |
195 | } |