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[HOST_NAME_MAX+1];
  55         static int initialized = 0;
  56         char *s;
  57
  58         if (initialized)
  59                 return (name);
  60
  61         if (config.mailname == NULL || !*config.mailname)
  62                 goto local;
  63
  64         if (config.mailname[0] == '/') {
  65                 /*
  66                  * If the mailname looks like an absolute path,
  67                  * treat it as a file.
  68                  */
  69                 FILE *fp;
  70
  71                 fp = fopen(config.mailname, "r");
  72                 if (fp == NULL)
  73                         goto local;
  74
  75                 s = fgets(name, sizeof(name), fp);
  76                 fclose(fp);
  77                 if (s == NULL)
  78                         goto local;
  79
  80                 for (s = name; *s != 0 && (isalnum(*s) || strchr("_.-", *s)); ++s)
  81                         /* NOTHING */;
  82                 *s = 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                 *name = 0;
  98         /*
  99          * gethostname() is allowed to truncate name without NUL-termination
 100          * and at the same time not return an error.
 101          */
 102         name[sizeof(name) - 1] = 0;
 103
 104         for (s = name; *s != 0 && (isalnum(*s) || strchr("_.-", *s)); ++s)
 105                 /* NOTHING */;
 106         *s = 0;
 107
 108         if (!*name)
 109                 snprintf(name, sizeof(name), "unknown-hostname");
 110
 111         initialized = 1;
 112         return (name);
 113 }
 114
 115 void
 116 setlogident(const char *fmt, ...)
 117 {
 118         static char tag[50];
 119
 120         snprintf(tag, sizeof(tag), "%s", logident_base);
 121         if (fmt != NULL) {
 122                 va_list ap;
 123                 char sufx[50];
 124
 125                 va_start(ap, fmt);
 126                 vsnprintf(sufx, sizeof(sufx), fmt, ap);
 127                 va_end(ap);
 128                 snprintf(tag, sizeof(tag), "%s[%s]", logident_base, sufx);
 129         }
 130         closelog();
 131         openlog(tag, 0, LOG_MAIL);
 132 }
 133
 134 void
 135 errlog(int exitcode, const char *fmt, ...)
 136 {
 137         int oerrno = errno;
 138         va_list ap;
 139         char outs[ERRMSG_SIZE];
 140
 141         outs[0] = 0;
 142         if (fmt != NULL) {
 143                 va_start(ap, fmt);
 144                 vsnprintf(outs, sizeof(outs), fmt, ap);
 145                 va_end(ap);
 146         }
 147
 148         errno = oerrno;
 149         if (*outs != 0) {
 150                 syslog(LOG_ERR, "%s: %m", outs);
 151                 fprintf(stderr, "%s: %s: %s\n", getprogname(), outs, strerror(oerrno));
 152         } else {
 153                 syslog(LOG_ERR, "%m");
 154                 fprintf(stderr, "%s: %s\n", getprogname(), strerror(oerrno));
 155         }
 156
 157         exit(exitcode);
 158 }
 159
 160 void
 161 errlogx(int exitcode, const char *fmt, ...)
 162 {
 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         if (*outs != 0) {
 174                 syslog(LOG_ERR, "%s", outs);
 175                 fprintf(stderr, "%s: %s\n", getprogname(), outs);
 176         } else {
 177                 syslog(LOG_ERR, "Unknown error");
 178                 fprintf(stderr, "%s: Unknown error\n", getprogname());
 179         }
 180
 181         exit(exitcode);
 182 }
 183
 184 static int
 185 check_username(const char *name, uid_t ckuid)
 186 {
 187         struct passwd *pwd;
 188
 189         if (name == NULL)
 190                 return (0);
 191         pwd = getpwnam(name);
 192         if (pwd == NULL || pwd->pw_uid != ckuid)
 193                 return (0);
 194         snprintf(username, sizeof(username), "%s", name);
 195         return (1);
 196 }
 197
 198 void
 199 set_username(void)
 200 {
 201         struct passwd *pwd;
 202
 203         useruid = getuid();
 204         if (check_username(getlogin(), useruid))
 205                 return;
 206         if (check_username(getenv("LOGNAME"), useruid))
 207                 return;
 208         if (check_username(getenv("USER"), useruid))
 209                 return;
 210         pwd = getpwuid(useruid);
 211         if (pwd != NULL && pwd->pw_name != NULL && pwd->pw_name[0] != '\0') {
 212                 if (check_username(pwd->pw_name, useruid))
 213                         return;
 214         }
 215         snprintf(username, sizeof(username), "uid=%ld", (long)useruid);
 216 }
 217
 218 void
 219 deltmp(void)
 220 {
 221         struct stritem *t;
 222
 223         SLIST_FOREACH(t, &tmpfs, next) {
 224                 unlink(t->str);
 225         }
 226 }
 227
 228 static sigjmp_buf sigbuf;
 229 static int sigbuf_valid;
 230
 231 static void
 232 sigalrm_handler(int signo)
 233 {
 234         (void)signo;    /* so that gcc doesn't complain */
 235         if (sigbuf_valid)
 236                 siglongjmp(sigbuf, 1);
 237 }
 238
 239 int
 240 do_timeout(int timeout, int dojmp)
 241 {
 242         struct sigaction act;
 243         int ret = 0;
 244
 245         sigemptyset(&act.sa_mask);
 246         act.sa_flags = 0;
 247
 248         if (timeout) {
 249                 act.sa_handler = sigalrm_handler;
 250                 if (sigaction(SIGALRM, &act, NULL) != 0)
 251                         syslog(LOG_WARNING, "can not set signal handler: %m");
 252                 if (dojmp) {
 253                         ret = sigsetjmp(sigbuf, 1);
 254                         if (ret)
 255                                 goto disable;
 256                         /* else just programmed */
 257                         sigbuf_valid = 1;
 258                 }
 259
 260                 alarm(timeout);
 261         } else {
 262 disable:
 263                 alarm(0);
 264
 265                 act.sa_handler = SIG_IGN;
 266                 if (sigaction(SIGALRM, &act, NULL) != 0)
 267                         syslog(LOG_WARNING, "can not remove signal handler: %m");
 268                 sigbuf_valid = 0;
 269         }
 270
 271         return (ret);
 272 }
 273
 274 int
 275 open_locked(const char *fname, int flags, ...)
 276 {
 277         int mode = 0;
 278
 279         if (flags & O_CREAT) {
 280                 va_list ap;
 281                 va_start(ap, flags);
 282                 mode = va_arg(ap, int);
 283                 va_end(ap);
 284         }
 285
 286 #ifndef O_EXLOCK
 287         int fd, save_errno;
 288
 289         fd = open(fname, flags, mode);
 290         if (fd < 0)
 291                 return(fd);
 292         if (flock(fd, LOCK_EX|((flags & O_NONBLOCK)? LOCK_NB: 0)) < 0) {
 293                 save_errno = errno;
 294                 close(fd);
 295                 errno = save_errno;
 296                 return(-1);
 297         }
 298         return(fd);
 299 #else
 300         return(open(fname, flags|O_EXLOCK, mode));
 301 #endif
 302 }
 303
 304 char *
 305 rfc822date(void)
 306 {
 307         static char str[50];
 308         size_t error;
 309         time_t now;
 310
 311         now = time(NULL);
 312         error = strftime(str, sizeof(str), "%a, %d %b %Y %T %z",
 313                        localtime(&now));
 314         if (error == 0)
 315                 strcpy(str, "(date fail)");
 316         return (str);
 317 }
 318
 319 int
 320 strprefixcmp(const char *str, const char *prefix)
 321 {
 322         return (strncasecmp(str, prefix, strlen(prefix)));
 323 }
 324
 325 void
 326 init_random(void)
 327 {
 328         unsigned int seed;
 329         int rf;
 330
 331         rf = open("/dev/urandom", O_RDONLY);
 332         if (rf == -1)
 333                 rf = open("/dev/random", O_RDONLY);
 334
 335         if (!(rf != -1 && read(rf, &seed, sizeof(seed)) == sizeof(seed)))
 336                 seed = (time(NULL) ^ getpid()) + (uintptr_t)&seed;
 337
 338         srandom(seed);
 339
 340         if (rf != -1)
 341                 close(rf);
 342 }