xref: /freebsd/contrib/dma/util.c (revision 716fd348e01c5f2ba125f878a634a753436c2994)
1 /*
2  * Copyright (c) 2008-2014, Simon Schubert <2@0x2c.org>.
3  * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
4  *
5  * This code is derived from software contributed to The DragonFly Project
6  * by Simon Schubert <2@0x2c.org>.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in
16  *    the documentation and/or other materials provided with the
17  *    distribution.
18  * 3. Neither the name of The DragonFly Project nor the names of its
19  *    contributors may be used to endorse or promote products derived
20  *    from this software without specific, prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
26  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/param.h>
37 #include <sys/file.h>
38 
39 #include <ctype.h>
40 #include <errno.h>
41 #include <fcntl.h>
42 #include <netdb.h>
43 #include <pwd.h>
44 #include <setjmp.h>
45 #include <signal.h>
46 #include <stdio.h>
47 #include <strings.h>
48 #include <string.h>
49 #include <syslog.h>
50 #include <unistd.h>
51 
52 #include "dma.h"
53 
54 const char *
55 hostname(void)
56 {
57 #ifndef HOST_NAME_MAX
58 #define HOST_NAME_MAX	255
59 #endif
60 	static char name[HOST_NAME_MAX+1];
61 	static int initialized = 0;
62 	char *s;
63 
64 	if (initialized)
65 		return (name);
66 
67 	if (config.mailname == NULL || !*config.mailname)
68 		goto local;
69 
70 	if (config.mailname[0] == '/') {
71 		/*
72 		 * If the mailname looks like an absolute path,
73 		 * treat it as a file.
74 		 */
75 		FILE *fp;
76 
77 		fp = fopen(config.mailname, "r");
78 		if (fp == NULL)
79 			goto local;
80 
81 		s = fgets(name, sizeof(name), fp);
82 		fclose(fp);
83 		if (s == NULL)
84 			goto local;
85 
86 		for (s = name; *s != 0 && (isalnum(*s) || strchr("_.-", *s)); ++s)
87 			/* NOTHING */;
88 		*s = 0;
89 
90 		if (!*name)
91 			goto local;
92 
93 		initialized = 1;
94 		return (name);
95 	} else {
96 		snprintf(name, sizeof(name), "%s", config.mailname);
97 		initialized = 1;
98 		return (name);
99 	}
100 
101 local:
102 	snprintf(name, sizeof(name), "%s", systemhostname());
103 
104 	initialized = 1;
105 	return (name);
106 }
107 
108 const char *
109 systemhostname(void)
110 {
111 #ifndef HOST_NAME_MAX
112 #define HOST_NAME_MAX	255
113 #endif
114 	static char name[HOST_NAME_MAX+1];
115 	static int initialized = 0;
116 	char *s;
117 
118 	if (initialized)
119 		return (name);
120 
121 	if (gethostname(name, sizeof(name)) != 0)
122 		*name = 0;
123 	/*
124 	 * gethostname() is allowed to truncate name without NUL-termination
125 	 * and at the same time not return an error.
126 	 */
127 	name[sizeof(name) - 1] = 0;
128 
129 	for (s = name; *s != 0 && (isalnum(*s) || strchr("_.-", *s)); ++s)
130 		/* NOTHING */;
131 	*s = 0;
132 
133 	if (!*name)
134 		snprintf(name, sizeof(name), "unknown-hostname");
135 
136 	initialized = 1;
137 	return (name);
138 }
139 
140 void
141 setlogident(const char *fmt, ...)
142 {
143 	static char tag[50];
144 
145 	snprintf(tag, sizeof(tag), "%s", logident_base);
146 	if (fmt != NULL) {
147 		va_list ap;
148 		char sufx[50];
149 
150 		va_start(ap, fmt);
151 		vsnprintf(sufx, sizeof(sufx), fmt, ap);
152 		va_end(ap);
153 		snprintf(tag, sizeof(tag), "%s[%s]", logident_base, sufx);
154 	}
155 	closelog();
156 	openlog(tag, 0, LOG_MAIL);
157 }
158 
159 void
160 errlog(int exitcode, const char *fmt, ...)
161 {
162 	int oerrno = errno;
163 	va_list ap;
164 	char outs[ERRMSG_SIZE];
165 
166 	outs[0] = 0;
167 	if (fmt != NULL) {
168 		va_start(ap, fmt);
169 		vsnprintf(outs, sizeof(outs), fmt, ap);
170 		va_end(ap);
171 	}
172 
173 	errno = oerrno;
174 	if (*outs != 0) {
175 		syslog(LOG_ERR, "%s: %m", outs);
176 		fprintf(stderr, "%s: %s: %s\n", getprogname(), outs, strerror(oerrno));
177 	} else {
178 		syslog(LOG_ERR, "%m");
179 		fprintf(stderr, "%s: %s\n", getprogname(), strerror(oerrno));
180 	}
181 
182 	exit(exitcode);
183 }
184 
185 void
186 errlogx(int exitcode, const char *fmt, ...)
187 {
188 	va_list ap;
189 	char outs[ERRMSG_SIZE];
190 
191 	outs[0] = 0;
192 	if (fmt != NULL) {
193 		va_start(ap, fmt);
194 		vsnprintf(outs, sizeof(outs), fmt, ap);
195 		va_end(ap);
196 	}
197 
198 	if (*outs != 0) {
199 		syslog(LOG_ERR, "%s", outs);
200 		fprintf(stderr, "%s: %s\n", getprogname(), outs);
201 	} else {
202 		syslog(LOG_ERR, "Unknown error");
203 		fprintf(stderr, "%s: Unknown error\n", getprogname());
204 	}
205 
206 	exit(exitcode);
207 }
208 
209 static int
210 check_username(const char *name, uid_t ckuid)
211 {
212 	struct passwd *pwd;
213 
214 	if (name == NULL)
215 		return (0);
216 	pwd = getpwnam(name);
217 	if (pwd == NULL || pwd->pw_uid != ckuid)
218 		return (0);
219 	snprintf(username, sizeof(username), "%s", name);
220 	return (1);
221 }
222 
223 void
224 set_username(void)
225 {
226 	struct passwd *pwd;
227 
228 	useruid = getuid();
229 	if (check_username(getlogin(), useruid))
230 		return;
231 	if (check_username(getenv("LOGNAME"), useruid))
232 		return;
233 	if (check_username(getenv("USER"), useruid))
234 		return;
235 	pwd = getpwuid(useruid);
236 	if (pwd != NULL && pwd->pw_name != NULL && pwd->pw_name[0] != '\0') {
237 		if (check_username(pwd->pw_name, useruid))
238 			return;
239 	}
240 	snprintf(username, sizeof(username), "uid=%ld", (long)useruid);
241 }
242 
243 void
244 deltmp(void)
245 {
246 	struct stritem *t;
247 
248 	SLIST_FOREACH(t, &tmpfs, next) {
249 		unlink(t->str);
250 	}
251 }
252 
253 static sigjmp_buf sigbuf;
254 static int sigbuf_valid;
255 
256 static void
257 sigalrm_handler(int signo)
258 {
259 	(void)signo;	/* so that gcc doesn't complain */
260 	if (sigbuf_valid)
261 		siglongjmp(sigbuf, 1);
262 }
263 
264 int
265 do_timeout(int timeout, int dojmp)
266 {
267 	struct sigaction act;
268 	int ret = 0;
269 
270 	sigemptyset(&act.sa_mask);
271 	act.sa_flags = 0;
272 
273 	if (timeout) {
274 		act.sa_handler = sigalrm_handler;
275 		if (sigaction(SIGALRM, &act, NULL) != 0)
276 			syslog(LOG_WARNING, "can not set signal handler: %m");
277 		if (dojmp) {
278 			ret = sigsetjmp(sigbuf, 1);
279 			if (ret)
280 				goto disable;
281 			/* else just programmed */
282 			sigbuf_valid = 1;
283 		}
284 
285 		alarm(timeout);
286 	} else {
287 disable:
288 		alarm(0);
289 
290 		act.sa_handler = SIG_IGN;
291 		if (sigaction(SIGALRM, &act, NULL) != 0)
292 			syslog(LOG_WARNING, "can not remove signal handler: %m");
293 		sigbuf_valid = 0;
294 	}
295 
296 	return (ret);
297 }
298 
299 int
300 open_locked(const char *fname, int flags, ...)
301 {
302 	int mode = 0;
303 
304 	if (flags & O_CREAT) {
305 		va_list ap;
306 		va_start(ap, flags);
307 		mode = va_arg(ap, int);
308 		va_end(ap);
309 	}
310 
311 #ifndef O_EXLOCK
312 	int fd, save_errno;
313 
314 	fd = open(fname, flags, mode);
315 	if (fd < 0)
316 		return(fd);
317 	if (flock(fd, LOCK_EX|((flags & O_NONBLOCK)? LOCK_NB: 0)) < 0) {
318 		save_errno = errno;
319 		close(fd);
320 		errno = save_errno;
321 		return(-1);
322 	}
323 	return(fd);
324 #else
325 	return(open(fname, flags|O_EXLOCK, mode));
326 #endif
327 }
328 
329 char *
330 rfc822date(void)
331 {
332 	static char str[50];
333 	size_t error;
334 	time_t now;
335 
336 	now = time(NULL);
337 	error = strftime(str, sizeof(str), "%a, %d %b %Y %T %z",
338 		       localtime(&now));
339 	if (error == 0)
340 		strcpy(str, "(date fail)");
341 	return (str);
342 }
343 
344 int
345 strprefixcmp(const char *str, const char *prefix)
346 {
347 	return (strncasecmp(str, prefix, strlen(prefix)));
348 }
349 
350 void
351 init_random(void)
352 {
353 	unsigned int seed;
354 	int rf;
355 
356 	rf = open("/dev/urandom", O_RDONLY);
357 	if (rf == -1)
358 		rf = open("/dev/random", O_RDONLY);
359 
360 	if (!(rf != -1 && read(rf, &seed, sizeof(seed)) == sizeof(seed)))
361 		seed = (time(NULL) ^ getpid()) + (uintptr_t)&seed;
362 
363 	srandom(seed);
364 
365 	if (rf != -1)
366 		close(rf);
367 }
368