src/modules/mail.c

   1 /*
   2     Copyright (C) 2001-2015 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, const char *rm)
 102 {
 103     static char buf[LINE_MAX];
 104     const 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 const 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(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd,
 157                              0)) == MAP_FAILED) {
 158             warn("%s", "mmap()");
 159             close (fd);
 160             return "!";
 161         }
 162
 163         close(fd);
 164     }
 165
 166     for (i = n = 0; aliasbuf[i]; i++) {
 167         char *last, *name, *tmp;
 168
 169         while (aliasbuf[i] != '\n')
 170             t[n++] = aliasbuf[i++];
 171
 172         t[n] = 0;
 173         n = 0;
 174
 175         if (t[0] == '#' || t[0] == '\0')
 176             continue;
 177
 178         last = t;
 179
 180         if ((name = strsep(&last, ":")) == NULL)
 181             continue;
 182
 183         if (strcmp(user, name) == 0) {
 184             while ((tmp = strsep(&last, ",")) != NULL) {
 185                 tmp = stripstr(tmp, " \n\t");
 186
 187                 safe_strncat(aliases, tmp, sizeof(aliases));
 188                 safe_strncat(aliases, m, sizeof(aliases));
 189             }
 190
 191             continue;
 192         }
 193
 194         while ((tmp = strsep(&last, ",")) != NULL) {
 195             tmp = stripstr(tmp, " \n\t");
 196
 197             if (strcmp(user, tmp) == 0) {
 198                 safe_strncat(aliases, name, sizeof(aliases));
 199                 safe_strncat(aliases, m, sizeof(aliases));
 200             }
 201         }
 202     }
 203
 204     if (aliases[0] == '\0')
 205         return "-";
 206     else
 207         aliases[strlen(aliases) - 1] = '\0';
 208
 209     p = aliases;
 210     return p;
 211 }
 212
 213 /* Returns a string of forward aliases for the user. Reads ~/.forward if it
 214  * exists and is readable. */
 215 static const char *forwards(const char *dir, const int multi)
 216 {
 217     FILE *fp;
 218     char buf[LINE_MAX], *s;
 219     static char buf2[LINE_MAX];
 220     int n = 0;
 221     char m[2] = { multi, '\0' };
 222
 223     snprintf(buf2, sizeof(buf2), "%s/.forward", dir);
 224
 225     if ((fp = fopen(buf2, "r")) == NULL) {
 226         if (errno == ENOENT)
 227             return "-";
 228         else
 229             return "!";
 230     }
 231
 232     buf2[0] = '\0';
 233
 234     while ((s = fgets(buf, sizeof(buf), fp)) != NULL) {
 235         if (buf[0] == '\n')
 236             continue;
 237
 238         if (buf[strlen(buf) - 1] == '\n')
 239             buf[strlen(buf) - 1] = '\0';
 240
 241         if (n++)
 242             safe_strncat(buf2, m, sizeof(buf2));
 243
 244         safe_strncat(buf2, buf, sizeof(buf2));
 245     }
 246
 247     fclose(fp);
 248
 249     if (!n)
 250         return "-";
 251
 252     s = buf2;
 253     return s;
 254 }
 255
 256 /* /var/mail/username folder size in bytes. */
 257 static char *foldersize(struct stat *st)
 258 {
 259     static char str[33], *p;
 260
 261     snprintf(str, sizeof(str), "%lu", (unsigned long) st->st_size);
 262     p = str;
 263     return p;
 264 }
 265
 266 /* This is output if the -h command line option is passed to the main program.
 267  */
 268 void ui_module_help()
 269 {
 270     printf("  Mail information [-M (-%s)]:\n", MAIL_OPTION_ORDER);
 271     printf("\t-f  forwarding addresses\t");
 272     printf("-a  mail aliases\n");
 273     printf("\t-r  folder access (read) time\t");
 274     printf("-m  folder modification time\n");
 275     printf("\t-s  folder size\n\n");
 276 }
 277
 278 /* This is the equivalent to main() only without argc and argv available. */
 279 int ui_module_exec(char ***s, const struct passwd *pw, const int multi_char,
 280               const int verbose, char *tf)
 281 {
 282     char *p = options;
 283     int gotstat = 0;
 284     struct stat st;
 285     char folder[PATH_MAX];
 286
 287     strings = *s;
 288     folder[0] = '\0';
 289     snprintf(folder, sizeof(folder), "%s/%s", _PATH_MAILDIR, pw->pw_name);
 290
 291     if (stat(folder, &st) != -1)
 292         gotstat = 1;
 293
 294     for (; *p; p++) {
 295         switch (*p) {
 296             case 's':
 297                 add_string(&strings, (gotstat) ? foldersize(&st) : "!");
 298                 break;
 299             case 'r':
 300                 add_string(&strings, (gotstat) ? stamp(st.st_atime, tf) : "!");
 301                 break;
 302             case 'm':
 303                 add_string(&strings, (gotstat) ? stamp(st.st_mtime, tf) : "!");
 304                 break;
 305             case 'f':
 306                 add_string(&strings, forwards(pw->pw_dir, multi_char));
 307                 break;
 308             case 'a':
 309                 add_string(&strings, mail_aliases(pw->pw_name, multi_char));
 310                 break;
 311             default:
 312                 break;
 313         }
 314     }
 315
 316     *s = strings;
 317     return EXIT_SUCCESS;
 318 }
 319
 320 const char *ui_module_options_init(char **defaults)
 321 {
 322     *defaults = (char *)"M";
 323     return MAIL_OPTION_STRING;
 324 }
 325
 326 /* Check module option validity. */
 327 int ui_module_options(int argc, char **argv)
 328 {
 329     int opt;
 330     char *p = options;
 331
 332     while ((opt = getopt(argc, argv, MAIL_OPTION_STRING)) != -1) {
 333         switch (opt) {
 334             case 'M':
 335                 strncpy(options, MAIL_OPTION_ORDER, sizeof(options));
 336                 return 0;
 337             case 'f':
 338             case 's':
 339             case 'r':
 340             case 'm':
 341             case 'a':
 342                 break;
 343             case '?':
 344                 warnx("mail: invalid option -- %c", optopt);
 345             default:
 346                 return 1;
 347         }
 348
 349         *p++ = opt;
 350         *p = '\0';
 351     }
 352
 353     return 0;
 354 }