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c49b3069 | 1 | /* Quagga signal handling functions. |
2 | * Copyright (C) 2004 Paul Jakma, | |
3 | * | |
4 | * This file is part of Quagga. | |
5 | * | |
6 | * Quagga is free software; you can redistribute it and/or modify it | |
7 | * under the terms of the GNU General Public License as published by the | |
8 | * Free Software Foundation; either version 2, or (at your option) any | |
9 | * later version. | |
10 | * | |
11 | * Quagga is distributed in the hope that it will be useful, but | |
12 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | * General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with Quagga; see the file COPYING. If not, write to the Free | |
18 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA | |
19 | * 02111-1307, USA. | |
20 | */ | |
21 | ||
22 | #include <zebra.h> | |
23 | #include <sigevent.h> | |
24 | #include <log.h> | |
837d16cc | 25 | #include <memory.h> |
c49b3069 | 26 | |
31364274 | 27 | #ifdef SA_SIGINFO |
40abf239 | 28 | #ifdef HAVE_UCONTEXT_H |
29 | #ifdef GNU_LINUX | |
30 | /* get REG_EIP from ucontext.h */ | |
67bf16c0 | 31 | #ifndef __USE_GNU |
40abf239 | 32 | #define __USE_GNU |
67bf16c0 | 33 | #endif /* __USE_GNU */ |
40abf239 | 34 | #endif /* GNU_LINUX */ |
35 | #include <ucontext.h> | |
36 | #endif /* HAVE_UCONTEXT_H */ | |
31364274 | 37 | #endif /* SA_SIGINFO */ |
40abf239 | 38 | |
39 | ||
05c447dd | 40 | /* master signals descriptor struct */ |
c49b3069 | 41 | struct quagga_sigevent_master_t |
42 | { | |
c49b3069 | 43 | struct thread *t; |
44 | ||
05c447dd | 45 | struct quagga_signal_t *signals; |
c49b3069 | 46 | int sigc; |
05c447dd | 47 | |
48 | volatile sig_atomic_t caught; | |
49 | } sigmaster; | |
c49b3069 | 50 | |
51 | /* Generic signal handler | |
52 | * Schedules signal event thread | |
53 | */ | |
59a06a91 | 54 | static void |
c49b3069 | 55 | quagga_signal_handler (int signo) |
56 | { | |
57 | int i; | |
58 | struct quagga_signal_t *sig; | |
59 | ||
60 | for (i = 0; i < sigmaster.sigc; i++) | |
61 | { | |
62 | sig = &(sigmaster.signals[i]); | |
63 | ||
64 | if (sig->signal == signo) | |
05c447dd | 65 | sig->caught = 1; |
c49b3069 | 66 | } |
05c447dd | 67 | |
68 | sigmaster.caught = 1; | |
c49b3069 | 69 | } |
70 | ||
05c447dd | 71 | /* check if signals have been caught and run appropriate handlers */ |
c49b3069 | 72 | int |
05c447dd | 73 | quagga_sigevent_process (void) |
c49b3069 | 74 | { |
c49b3069 | 75 | struct quagga_signal_t *sig; |
76 | int i; | |
05c447dd | 77 | #ifdef SIGEVENT_BLOCK_SIGNALS |
78 | /* shouldnt need to block signals, but potentially may be needed */ | |
79 | sigset_t newmask, oldmask; | |
c49b3069 | 80 | |
b7797131 | 81 | /* |
82 | * Block most signals, but be careful not to defer SIGTRAP because | |
83 | * doing so breaks gdb, at least on NetBSD 2.0. Avoid asking to | |
84 | * block SIGKILL, just because we shouldn't be able to do so. | |
85 | */ | |
c49b3069 | 86 | sigfillset (&newmask); |
b7797131 | 87 | sigdelset (&newmask, SIGTRAP); |
88 | sigdelset (&newmask, SIGKILL); | |
05c447dd | 89 | |
c49b3069 | 90 | if ( (sigprocmask (SIG_BLOCK, &newmask, &oldmask)) < 0) |
91 | { | |
92 | zlog_err ("quagga_signal_timer: couldnt block signals!"); | |
c49b3069 | 93 | return -1; |
94 | } | |
05c447dd | 95 | #endif /* SIGEVENT_BLOCK_SIGNALS */ |
96 | ||
97 | if (sigmaster.caught > 0) | |
c49b3069 | 98 | { |
05c447dd | 99 | sigmaster.caught = 0; |
100 | /* must not read or set sigmaster.caught after here, | |
101 | * race condition with per-sig caught flags if one does | |
102 | */ | |
103 | ||
104 | for (i = 0; i < sigmaster.sigc; i++) | |
c49b3069 | 105 | { |
05c447dd | 106 | sig = &(sigmaster.signals[i]); |
107 | ||
108 | if (sig->caught > 0) | |
109 | { | |
110 | sig->caught = 0; | |
111 | sig->handler (); | |
112 | } | |
c49b3069 | 113 | } |
114 | } | |
c49b3069 | 115 | |
05c447dd | 116 | #ifdef SIGEVENT_BLOCK_SIGNALS |
c49b3069 | 117 | if ( sigprocmask (SIG_UNBLOCK, &oldmask, NULL) < 0 ); |
118 | return -1; | |
05c447dd | 119 | #endif /* SIGEVENT_BLOCK_SIGNALS */ |
120 | ||
c49b3069 | 121 | return 0; |
122 | } | |
123 | ||
05c447dd | 124 | #ifdef SIGEVENT_SCHEDULE_THREAD |
125 | /* timer thread to check signals. Shouldnt be needed */ | |
126 | int | |
127 | quagga_signal_timer (struct thread *t) | |
128 | { | |
129 | struct quagga_sigevent_master_t *sigm; | |
130 | struct quagga_signal_t *sig; | |
131 | int i; | |
132 | ||
133 | sigm = THREAD_ARG (t); | |
134 | sigm->t = thread_add_timer (sigm->t->master, quagga_signal_timer, &sigmaster, | |
135 | QUAGGA_SIGNAL_TIMER_INTERVAL); | |
136 | return quagga_sigevent_process (); | |
137 | } | |
138 | #endif /* SIGEVENT_SCHEDULE_THREAD */ | |
139 | ||
c49b3069 | 140 | /* Initialization of signal handles. */ |
40abf239 | 141 | /* Signal wrapper. */ |
59a06a91 | 142 | static int |
c49b3069 | 143 | signal_set (int signo) |
144 | { | |
145 | int ret; | |
146 | struct sigaction sig; | |
147 | struct sigaction osig; | |
148 | ||
149 | sig.sa_handler = &quagga_signal_handler; | |
150 | sigfillset (&sig.sa_mask); | |
151 | sig.sa_flags = 0; | |
152 | if (signo == SIGALRM) { | |
153 | #ifdef SA_INTERRUPT | |
154 | sig.sa_flags |= SA_INTERRUPT; /* SunOS */ | |
155 | #endif | |
156 | } else { | |
157 | #ifdef SA_RESTART | |
158 | sig.sa_flags |= SA_RESTART; | |
159 | #endif /* SA_RESTART */ | |
160 | } | |
161 | ||
162 | ret = sigaction (signo, &sig, &osig); | |
163 | if (ret < 0) | |
164 | return ret; | |
165 | else | |
166 | return 0; | |
167 | } | |
168 | ||
31364274 | 169 | #ifdef SA_SIGINFO |
170 | ||
40abf239 | 171 | /* XXX This function should be enhanced to support more platforms |
172 | (it currently works only on Linux/x86). */ | |
173 | static void * | |
174 | program_counter(void *context) | |
175 | { | |
176 | #ifdef HAVE_UCONTEXT_H | |
177 | #ifdef GNU_LINUX | |
bccbd141 JT |
178 | /* these are from GNU libc, rather than Linux, strictly speaking */ |
179 | # if defined(REG_EIP) | |
180 | # define REG_INDEX REG_EIP | |
181 | # elif defined(REG_RIP) | |
182 | # define REG_INDEX REG_RIP | |
183 | # elif defined(__powerpc__) | |
184 | # define REG_INDEX 32 | |
185 | # endif | |
186 | #elif defined(SUNOS_5) /* !GNU_LINUX */ | |
187 | # define REG_INDEX REG_PC | |
40abf239 | 188 | #endif /* GNU_LINUX */ |
bccbd141 JT |
189 | |
190 | #ifdef REG_INDEX | |
191 | # ifdef HAVE_UCONTEXT_T_UC_MCONTEXT_GREGS | |
192 | # define REGS gregs[REG_INDEX] | |
193 | # elif defined(HAVE_UCONTEXT_T_UC_MCONTEXT_UC_REGS) | |
194 | # define REGS uc_regs->gregs[REG_INDEX] | |
195 | # endif /* HAVE_UCONTEXT_T_UC_MCONTEXT_GREGS */ | |
196 | #endif /* REG_INDEX */ | |
197 | ||
198 | #ifdef REGS | |
199 | if (context) | |
200 | return (void *)(((ucontext_t *)context)->uc_mcontext.REGS); | |
201 | #elif defined(HAVE_UCONTEXT_T_UC_MCONTEXT_REGS__NIP) | |
202 | /* older Linux / struct pt_regs ? */ | |
203 | if (context) | |
204 | return (void *)(((ucontext_t *)context)->uc_mcontext.regs->nip); | |
205 | #endif /* REGS */ | |
206 | ||
40abf239 | 207 | #endif /* HAVE_UCONTEXT_H */ |
208 | return NULL; | |
209 | } | |
210 | ||
31364274 | 211 | #endif /* SA_SIGINFO */ |
212 | ||
8cc4198f | 213 | static void __attribute__ ((noreturn)) |
31364274 | 214 | exit_handler(int signo |
215 | #ifdef SA_SIGINFO | |
216 | , siginfo_t *siginfo, void *context | |
217 | #endif | |
218 | ) | |
59a06a91 | 219 | { |
31364274 | 220 | zlog_signal(signo, "exiting..." |
221 | #ifdef SA_SIGINFO | |
222 | , siginfo, program_counter(context) | |
223 | #endif | |
224 | ); | |
59a06a91 | 225 | _exit(128+signo); |
226 | } | |
227 | ||
8cc4198f | 228 | static void __attribute__ ((noreturn)) |
31364274 | 229 | core_handler(int signo |
230 | #ifdef SA_SIGINFO | |
231 | , siginfo_t *siginfo, void *context | |
232 | #endif | |
233 | ) | |
59a06a91 | 234 | { |
31364274 | 235 | zlog_signal(signo, "aborting..." |
236 | #ifdef SA_SIGINFO | |
237 | , siginfo, program_counter(context) | |
238 | #endif | |
239 | ); | |
59a06a91 | 240 | abort(); |
241 | } | |
242 | ||
243 | static void | |
244 | trap_default_signals(void) | |
245 | { | |
246 | static const int core_signals[] = { | |
247 | SIGQUIT, | |
248 | SIGILL, | |
249 | #ifdef SIGEMT | |
250 | SIGEMT, | |
251 | #endif | |
252 | SIGFPE, | |
253 | SIGBUS, | |
254 | SIGSEGV, | |
255 | #ifdef SIGSYS | |
256 | SIGSYS, | |
257 | #endif | |
258 | #ifdef SIGXCPU | |
259 | SIGXCPU, | |
260 | #endif | |
261 | #ifdef SIGXFSZ | |
262 | SIGXFSZ, | |
263 | #endif | |
264 | }; | |
265 | static const int exit_signals[] = { | |
266 | SIGHUP, | |
267 | SIGINT, | |
59a06a91 | 268 | SIGALRM, |
269 | SIGTERM, | |
270 | SIGUSR1, | |
271 | SIGUSR2, | |
272 | #ifdef SIGPOLL | |
273 | SIGPOLL, | |
274 | #endif | |
275 | #ifdef SIGVTALRM | |
276 | SIGVTALRM, | |
277 | #endif | |
278 | #ifdef SIGSTKFLT | |
279 | SIGSTKFLT, | |
280 | #endif | |
281 | }; | |
81fc57ca | 282 | static const int ignore_signals[] = { |
283 | SIGPIPE, | |
284 | }; | |
59a06a91 | 285 | static const struct { |
286 | const int *sigs; | |
81fc57ca | 287 | u_int nsigs; |
31364274 | 288 | void (*handler)(int signo |
289 | #ifdef SA_SIGINFO | |
290 | , siginfo_t *info, void *context | |
291 | #endif | |
292 | ); | |
81fc57ca | 293 | } sigmap[] = { |
837d16cc B |
294 | { core_signals, array_size(core_signals), core_handler}, |
295 | { exit_signals, array_size(exit_signals), exit_handler}, | |
296 | { ignore_signals, array_size(ignore_signals), NULL}, | |
59a06a91 | 297 | }; |
81fc57ca | 298 | u_int i; |
59a06a91 | 299 | |
837d16cc | 300 | for (i = 0; i < array_size(sigmap); i++) |
59a06a91 | 301 | { |
81fc57ca | 302 | u_int j; |
59a06a91 | 303 | |
304 | for (j = 0; j < sigmap[i].nsigs; j++) | |
305 | { | |
306 | struct sigaction oact; | |
307 | if ((sigaction(sigmap[i].sigs[j],NULL,&oact) == 0) && | |
308 | (oact.sa_handler == SIG_DFL)) | |
309 | { | |
310 | struct sigaction act; | |
59a06a91 | 311 | sigfillset (&act.sa_mask); |
40abf239 | 312 | if (sigmap[i].handler == NULL) |
313 | { | |
314 | act.sa_handler = SIG_IGN; | |
315 | act.sa_flags = 0; | |
316 | } | |
317 | else | |
318 | { | |
31364274 | 319 | #ifdef SA_SIGINFO |
40abf239 | 320 | /* Request extra arguments to signal handler. */ |
321 | act.sa_sigaction = sigmap[i].handler; | |
322 | act.sa_flags = SA_SIGINFO; | |
31364274 | 323 | #else |
324 | act.sa_handler = sigmap[i].handler; | |
325 | act.sa_flags = 0; | |
326 | #endif | |
40abf239 | 327 | } |
59a06a91 | 328 | if (sigaction(sigmap[i].sigs[j],&act,NULL) < 0) |
329 | zlog_warn("Unable to set signal handler for signal %d: %s", | |
330 | sigmap[i].sigs[j],safe_strerror(errno)); | |
331 | ||
332 | } | |
333 | } | |
334 | } | |
335 | } | |
336 | ||
c49b3069 | 337 | void |
05c447dd | 338 | signal_init (struct thread_master *m, int sigc, |
339 | struct quagga_signal_t signals[]) | |
c49b3069 | 340 | { |
341 | ||
342 | int i = 0; | |
343 | struct quagga_signal_t *sig; | |
59a06a91 | 344 | |
345 | /* First establish some default handlers that can be overridden by | |
346 | the application. */ | |
347 | trap_default_signals(); | |
c49b3069 | 348 | |
349 | while (i < sigc) | |
350 | { | |
351 | sig = &signals[i]; | |
352 | if ( signal_set (sig->signal) < 0 ) | |
353 | exit (-1); | |
354 | i++; | |
355 | } | |
356 | ||
357 | sigmaster.sigc = sigc; | |
358 | sigmaster.signals = signals; | |
05c447dd | 359 | |
360 | #ifdef SIGEVENT_SCHEDULE_THREAD | |
c49b3069 | 361 | sigmaster.t = |
362 | thread_add_timer (m, quagga_signal_timer, &sigmaster, | |
363 | QUAGGA_SIGNAL_TIMER_INTERVAL); | |
05c447dd | 364 | #endif /* SIGEVENT_SCHEDULE_THREAD */ |
c49b3069 | 365 | } |