util.c

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