src/modules/mail.c

   1 /*
   2     Copyright (C) 2001-2013 Ben Kibbey <bjk@luxsci.net>
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02110-1301  USA
  17 */
  18 #ifdef HAVE_CONFIG_H
  19 #include <config.h>
  20 #endif
  21
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <unistd.h>
  25 #include <sys/types.h>
  26 #include <sys/stat.h>
  27 #include <errno.h>
  28 #include <pwd.h>
  29
  30 #ifdef HAVE_FCNTL_H
  31 #include <fcntl.h>
  32 #endif
  33
  34 #ifdef HAVE_STRING_H
  35 #include <string.h>
  36 #endif
  37
  38 #ifdef HAVE_LIMITS_H
  39 #include <limits.h>
  40 #ifndef LINE_MAX
  41 #ifdef _POSIX2_LINE_MAX
  42 #define LINE_MAX _POSIX2_LINE_MAX
  43 #else
  44 #define LINE_MAX 2048
  45 #endif
  46 #endif
  47 #endif
  48
  49 #ifdef HAVE_SYS_MMAN_H
  50 #include <sys/mman.h>
  51 #endif
  52
  53 #ifdef HAVE_ERR_H
  54 #include <err.h>
  55 #endif
  56
  57 #ifdef HAVE_PATHS_H
  58 #include <paths.h>
  59 #endif
  60 #ifndef _PATH_MAILDIR
  61 #define _PATH_MAILDIR           "/var/mail"
  62 #endif
  63
  64 #ifndef HAVE_ERR_H
  65 #include "../err.c"
  66 #endif
  67
  68 #ifndef HAVE_STRSEP
  69 #include "../strsep.c"
  70 #endif
  71
  72 #ifdef WITH_DMALLOC
  73 #include <dmalloc.h>
  74 #endif
  75
  76 #define MAIL_OPTION_ORDER       "smrfa"
  77 #define MAIL_OPTION_STRING      "Mfrsam"
  78
  79 static char options[6];         /* NULL terminated. */
  80 static char *aliasbuf;
  81 static char **strings;
  82
  83 void add_string(char ***, const char *);
  84 char *stamp(time_t, const char *);
  85 char *safe_strncat(char *, const char *, size_t);
  86
  87 void ui_module_init(int *chainable)
  88 {
  89     *chainable = 0;
  90 }
  91
  92 void ui_module_exit()
  93 {
  94     if (aliasbuf)
  95         munmap(aliasbuf, strlen(aliasbuf));
  96
  97     aliasbuf = NULL;
  98 }
  99
 100 /* Remove characters (rm) from string (str). */
 101 static char *stripstr(char *str, char *rm)
 102 {
 103     static char buf[LINE_MAX];
 104     char *orm;
 105     int i = 0;
 106
 107     if (rm == NULL || str == NULL)
 108         return str;
 109
 110     while (*str) {
 111         orm = rm;
 112
 113         while (*orm) {
 114             if (*str == *orm) {
 115                 str++;
 116                 continue;
 117             }
 118
 119             orm++;
 120         }
 121
 122         buf[i++] = *str++;
 123     }
 124
 125     buf[i] = '\0';
 126     return buf;
 127 }
 128
 129 /* Return a string of mail aliases for the user. Looks in /etc/aliases (or
 130  * whatever was specified at compile-time). The file is read into a buffer
 131  * only once (mmap(2)). */
 132 static char *mail_aliases(const char *user, const int multi)
 133 {
 134     char t[LINE_MAX];
 135     static char aliases[LINE_MAX], *p;
 136     static int firstrun;
 137     int i, n;
 138     struct stat st;
 139     char m[2] = { multi, '\0' };
 140     int fd;
 141
 142     aliases[0] = '\0';
 143
 144     if ((!aliasbuf && firstrun) || aliasbuf == MAP_FAILED)
 145         return "!";
 146
 147     if (!aliasbuf) {
 148         firstrun = 1;
 149
 150         if (stat(ALIAS_FILE, &st) == -1)
 151             return "!";
 152
 153         if ((fd = open(ALIAS_FILE, O_RDONLY)) == -1)
 154             return "!";
 155
 156         if ((aliasbuf = mmap(0, st.st_size, PROT_READ, MAP_PRIVATE, fd,
 157                              0)) == MAP_FAILED) {
 158             warn("%s", "mmap()");
 159             return "!";
 160         }
 161
 162         close(fd);
 163     }
 164
 165     for (i = n = 0; aliasbuf[i]; i++) {
 166         char *last, *name, *tmp;
 167
 168         while (aliasbuf[i] != '\n')
 169             t[n++] = aliasbuf[i++];
 170
 171         t[n] = 0;
 172         n = 0;
 173
 174         if (t[0] == '#' || t[0] == '\0')
 175             continue;
 176
 177         last = t;
 178
 179         if ((name = strsep(&last, ":")) == NULL)
 180             continue;
 181
 182         if (strcmp(user, name) == 0) {
 183             while ((tmp = strsep(&last, ",")) != NULL) {
 184                 tmp = stripstr(tmp, " \n\t");
 185
 186                 safe_strncat(aliases, tmp, sizeof(aliases));
 187                 safe_strncat(aliases, m, sizeof(aliases));
 188             }
 189
 190             continue;
 191         }
 192
 193         while ((tmp = strsep(&last, ",")) != NULL) {
 194             tmp = stripstr(tmp, " \n\t");
 195
 196             if (strcmp(user, tmp) == 0) {
 197                 safe_strncat(aliases, name, sizeof(aliases));
 198                 safe_strncat(aliases, m, sizeof(aliases));
 199             }
 200         }
 201     }
 202
 203     if (aliases[0] == '\0')
 204         return "-";
 205     else
 206         aliases[strlen(aliases) - 1] = '\0';
 207
 208     p = aliases;
 209     return p;
 210 }
 211
 212 /* Returns a string of forward aliases for the user. Reads ~/.forward if it
 213  * exists and is readable. */
 214 static char *forwards(const char *dir, const int multi)
 215 {
 216     FILE *fp;
 217     char buf[LINE_MAX], *s;
 218     static char buf2[LINE_MAX];
 219     int n = 0;
 220     char m[2] = { multi, '\0' };
 221
 222     snprintf(buf2, sizeof(buf2), "%s/.forward", dir);
 223
 224     if ((fp = fopen(buf2, "r")) == NULL) {
 225         if (errno == ENOENT)
 226             return "-";
 227         else
 228             return "!";
 229     }
 230
 231     buf2[0] = '\0';
 232
 233     while ((s = fgets(buf, sizeof(buf), fp)) != NULL) {
 234         if (buf[0] == '\n')
 235             continue;
 236
 237         if (buf[strlen(buf) - 1] == '\n')
 238             buf[strlen(buf) - 1] = '\0';
 239
 240         if (n++)
 241             safe_strncat(buf2, m, sizeof(buf2));
 242
 243         safe_strncat(buf2, buf, sizeof(buf2));
 244     }
 245
 246     fclose(fp);
 247
 248     if (!n)
 249         return "-";
 250
 251     s = buf2;
 252     return s;
 253 }
 254
 255 /* /var/mail/username folder size in bytes. */
 256 static char *foldersize(struct stat st)
 257 {
 258     static char str[33], *p;
 259
 260     snprintf(str, sizeof(str), "%lu", (unsigned long) st.st_size);
 261     p = str;
 262     return p;
 263 }
 264
 265 /* This is output if the -h command line option is passed to the main program.
 266  */
 267 void ui_module_help()
 268 {
 269     printf("  Mail information [-M (-%s)]:\n", MAIL_OPTION_ORDER);
 270     printf("\t-f  forwarding addresses\t");
 271     printf("-a  mail aliases\n");
 272     printf("\t-r  folder access (read) time\t");
 273     printf("-m  folder modification time\n");
 274     printf("\t-s  folder size\n\n");
 275 }
 276
 277 /* This is the equivalent to main() only without argc and argv available. */
 278 int ui_module_exec(char ***s, const struct passwd *pw, const int multi_char,
 279               const int verbose, char *tf)
 280 {
 281     char *p = options;
 282     int gotstat = 0;
 283     struct stat st;
 284     char folder[PATH_MAX];
 285
 286     strings = *s;
 287     folder[0] = '\0';
 288     snprintf(folder, sizeof(folder), "%s/%s", _PATH_MAILDIR, pw->pw_name);
 289
 290     if (stat(folder, &st) != -1)
 291         gotstat = 1;
 292
 293     for (; *p; p++) {
 294         switch (*p) {
 295             case 's':
 296                 add_string(&strings, (gotstat) ? foldersize(st) : "!");
 297                 break;
 298             case 'r':
 299                 add_string(&strings, (gotstat) ? stamp(st.st_atime, tf) : "!");
 300                 break;
 301             case 'm':
 302                 add_string(&strings, (gotstat) ? stamp(st.st_mtime, tf) : "!");
 303                 break;
 304             case 'f':
 305                 add_string(&strings, forwards(pw->pw_dir, multi_char));
 306                 break;
 307             case 'a':
 308                 add_string(&strings, mail_aliases(pw->pw_name, multi_char));
 309                 break;
 310             default:
 311                 break;
 312         }
 313     }
 314
 315     *s = strings;
 316     return EXIT_SUCCESS;
 317 }
 318
 319 char *ui_module_options_init(char **defaults)
 320 {
 321     *defaults = "M";
 322     return MAIL_OPTION_STRING;
 323 }
 324
 325 /* Check module option validity. */
 326 int ui_module_options(int argc, char **argv)
 327 {
 328     int opt;
 329     char *p = options;
 330
 331     while ((opt = getopt(argc, argv, MAIL_OPTION_STRING)) != -1) {
 332         switch (opt) {
 333             case 'M':
 334                 strncpy(options, MAIL_OPTION_ORDER, sizeof(options));
 335                 return 0;
 336             case 'f':
 337             case 's':
 338             case 'r':
 339             case 'm':
 340             case 'a':
 341                 break;
 342             case '?':
 343                 warnx("mail: invalid option -- %c", optopt);
 344             default:
 345                 return 1;
 346         }
 347
 348         *p++ = opt;
 349         *p = '\0';
 350     }
 351
 352     return 0;
 353 }