lib-src/fakemail.c

   1 /* sendmail-like interface to /bin/mail for system V,
   2    Copyright (C) 1985, 1994, 1999, 2002, 2003, 2004,
   3                  2005, 2006 Free Software Foundation, Inc.
   4
   5 This file is part of GNU Emacs.
   6
   7 GNU Emacs is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GNU Emacs is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU Emacs; see the file COPYING.  If not, write to
  19 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20 Boston, MA 02110-1301, USA.  */
  21
  22 #define NO_SHORTNAMES
  23 #define _XOPEN_SOURCE 500       /* for cuserid */
  24
  25 #ifdef HAVE_CONFIG_H
  26 #include <config.h>
  27 #endif
  28
  29 #if defined (BSD_SYSTEM) && !defined (BSD4_1) && !defined (USE_FAKEMAIL)
  30 /* This program isnot used in BSD, so just avoid loader complaints.  */
  31 int
  32 main ()
  33 {
  34   return 0;
  35 }
  36 #else /* not BSD 4.2 (or newer) */
  37 #ifdef MSDOS
  38 int
  39 main ()
  40 {
  41   return 0;
  42 }
  43 #else /* not MSDOS */
  44 /* This conditional contains all the rest of the file.  */
  45
  46 /* These are defined in config in some versions. */
  47
  48 #ifdef static
  49 #undef static
  50 #endif
  51
  52 #ifdef WINDOWSNT
  53 #include "ntlib.h"
  54 #endif
  55
  56 #include <limits.h>
  57 #include <stdio.h>
  58 #include <string.h>
  59 #include <ctype.h>
  60 #include <time.h>
  61 #include <pwd.h>
  62
  63 /* This is to declare cuserid.  */
  64 #ifdef HAVE_UNISTD_H
  65 #include <unistd.h>
  66 #endif
  67 \f
  68 /* Type definitions */
  69
  70 #define boolean int
  71 #define true 1
  72 #define false 0
  73
  74 /* True if TM_YEAR is a struct tm's tm_year value that is acceptable
  75    to asctime.  Glibc asctime returns a useful string unless TM_YEAR
  76    is nearly INT_MAX, but the C Standard lets C libraries overrun a
  77    buffer if TM_YEAR needs more than 4 bytes.  */
  78 #ifdef __GLIBC__
  79 # define TM_YEAR_IN_ASCTIME_RANGE(tm_year) ((tm_year) <= INT_MAX - 1900)
  80 #else
  81 # define TM_YEAR_IN_ASCTIME_RANGE(tm_year) \
  82     (-999 - 1900 <= (tm_year) && (tm_year) <= 9999 - 1900)
  83 #endif
  84
  85 /* Various lists */
  86
  87 struct line_record
  88 {
  89   char *string;
  90   struct line_record *continuation;
  91 };
  92 typedef struct line_record *line_list;
  93
  94 struct header_record
  95 {
  96   line_list text;
  97   struct header_record *next;
  98   struct header_record *previous;
  99 };
 100 typedef struct header_record *header;
 101
 102 struct stream_record
 103 {
 104   FILE *handle;
 105   int (*action)();
 106   struct stream_record *rest_streams;
 107 };
 108 typedef struct stream_record *stream_list;
 109
 110 /* A `struct linebuffer' is a structure which holds a line of text.
 111  * `readline' reads a line from a stream into a linebuffer
 112  * and works regardless of the length of the line.
 113  */
 114
 115 struct linebuffer
 116 {
 117   long size;
 118   char *buffer;
 119 };
 120
 121 struct linebuffer lb;
 122
 123 #define new_list()                                      \
 124   ((line_list) xmalloc (sizeof (struct line_record)))
 125 #define new_header()                            \
 126   ((header) xmalloc (sizeof (struct header_record)))
 127 #define new_stream()                            \
 128   ((stream_list) xmalloc (sizeof (struct stream_record)))
 129 #define alloc_string(nchars)                            \
 130   ((char *) xmalloc ((nchars) + 1))
 131 \f
 132 /* Global declarations */
 133
 134 #define BUFLEN 1024
 135 #define KEYWORD_SIZE 256
 136 #define FROM_PREFIX "From"
 137 #define MY_NAME "fakemail"
 138 #define NIL ((line_list) NULL)
 139 #define INITIAL_LINE_SIZE 200
 140
 141 #ifndef MAIL_PROGRAM_NAME
 142 #define MAIL_PROGRAM_NAME "/bin/mail"
 143 #endif
 144
 145 static char *my_name;
 146 static char *the_date;
 147 static char *the_user;
 148 static line_list file_preface;
 149 static stream_list the_streams;
 150 static boolean no_problems = true;
 151
 152 extern FILE *popen ();
 153 extern int fclose (), pclose ();
 154
 155 #ifdef CURRENT_USER
 156 extern struct passwd *getpwuid ();
 157 extern unsigned short geteuid ();
 158 static struct passwd *my_entry;
 159 #define cuserid(s)                              \
 160 (my_entry = getpwuid (((int) geteuid ())),      \
 161  my_entry->pw_name)
 162 #endif
 163 \f
 164 /* Utilities */
 165
 166 /* Print error message.  `s1' is printf control string, `s2' is arg for it. */
 167
 168 static void
 169 error (s1, s2)
 170      char *s1, *s2;
 171 {
 172   printf ("%s: ", my_name);
 173   printf (s1, s2);
 174   printf ("\n");
 175   no_problems = false;
 176 }
 177
 178 /* Print error message and exit.  */
 179
 180 static void
 181 fatal (s1, s2)
 182      char *s1, *s2;
 183 {
 184   error (s1, s2);
 185   exit (EXIT_FAILURE);
 186 }
 187
 188 /* Like malloc but get fatal error if memory is exhausted.  */
 189
 190 static long *
 191 xmalloc (size)
 192      int size;
 193 {
 194   long *result = (long *) malloc (((unsigned) size));
 195   if (result == ((long *) NULL))
 196     fatal ("virtual memory exhausted", 0);
 197   return result;
 198 }
 199
 200 static long *
 201 xrealloc (ptr, size)
 202      long *ptr;
 203      int size;
 204 {
 205   long *result = (long *) realloc (ptr, ((unsigned) size));
 206   if (result == ((long *) NULL))
 207     fatal ("virtual memory exhausted");
 208   return result;
 209 }
 210 \f
 211 /* Initialize a linebuffer for use */
 212
 213 void
 214 init_linebuffer (linebuffer)
 215      struct linebuffer *linebuffer;
 216 {
 217   linebuffer->size = INITIAL_LINE_SIZE;
 218   linebuffer->buffer = ((char *) xmalloc (INITIAL_LINE_SIZE));
 219 }
 220
 221 /* Read a line of text from `stream' into `linebuffer'.
 222    Return the length of the line.  */
 223
 224 long
 225 readline (linebuffer, stream)
 226      struct linebuffer *linebuffer;
 227      FILE *stream;
 228 {
 229   char *buffer = linebuffer->buffer;
 230   char *p = linebuffer->buffer;
 231   char *end = p + linebuffer->size;
 232
 233   while (true)
 234     {
 235       int c = getc (stream);
 236       if (p == end)
 237         {
 238           linebuffer->size *= 2;
 239           buffer = ((char *) xrealloc ((long *)buffer, linebuffer->size));
 240           p = buffer + (p - linebuffer->buffer);
 241           end = buffer + linebuffer->size;
 242           linebuffer->buffer = buffer;
 243         }
 244       if (c < 0 || c == '\n')
 245         {
 246           *p = 0;
 247           break;
 248         }
 249       *p++ = c;
 250     }
 251
 252   return p - buffer;
 253 }
 254 \f
 255 /* Extract a colon-terminated keyword from the string FIELD.
 256    Return that keyword as a string stored in a static buffer.
 257    Store the address of the rest of the string into *REST.
 258
 259    If there is no keyword, return NULL and don't alter *REST.  */
 260
 261 char *
 262 get_keyword (field, rest)
 263      register char *field;
 264      char **rest;
 265 {
 266   static char keyword[KEYWORD_SIZE];
 267   register char *ptr;
 268   register int c;
 269
 270   ptr = &keyword[0];
 271   c = (unsigned char) *field++;
 272   if (isspace (c) || c == ':')
 273     return ((char *) NULL);
 274   *ptr++ = (islower (c) ? toupper (c) : c);
 275   while (((c = (unsigned char) *field++) != ':') && ! isspace (c))
 276     *ptr++ = (islower (c) ? toupper (c) : c);
 277   *ptr++ = '\0';
 278   while (isspace (c))
 279     c = (unsigned char) *field++;
 280   if (c != ':')
 281     return ((char *) NULL);
 282   *rest = field;
 283   return &keyword[0];
 284 }
 285
 286 /* Nonzero if the string FIELD starts with a colon-terminated keyword.  */
 287
 288 boolean
 289 has_keyword (field)
 290      char *field;
 291 {
 292   char *ignored;
 293   return (get_keyword (field, &ignored) != ((char *) NULL));
 294 }
 295
 296 /* Store the string FIELD, followed by any lines in THE_LIST,
 297    into the buffer WHERE.
 298    Concatenate lines, putting just a space between them.
 299    Delete everything contained in parentheses.
 300    When a recipient name contains <...>, we discard
 301    everything except what is inside the <...>.
 302
 303    We don't pay attention to overflowing WHERE;
 304    the caller has to make it big enough.  */
 305
 306 char *
 307 add_field (the_list, field, where)
 308      line_list the_list;
 309      register char *field, *where;
 310 {
 311   register char c;
 312   while (true)
 313     {
 314       char *this_recipient_where;
 315       int in_quotes = 0;
 316
 317       *where++ = ' ';
 318       this_recipient_where = where;
 319
 320       while ((c = *field++) != '\0')
 321         {
 322           if (c == '\\')
 323             *where++ = c;
 324           else if (c == '"')
 325             {
 326               in_quotes = ! in_quotes;
 327               *where++ = c;
 328             }
 329           else if (in_quotes)
 330             *where++ = c;
 331           else if (c == '(')
 332             {
 333               while (*field && *field != ')') ++field;
 334               if (! (*field++)) break; /* no close */
 335               continue;
 336             }
 337           else if (c == ',')
 338             {
 339               *where++ = ' ';
 340               /* When we get to the end of one recipient,
 341                  don't discard it if the next one has <...>.  */
 342               this_recipient_where = where;
 343             }
 344           else if (c == '<')
 345             /* Discard everything we got before the `<'.  */
 346             where = this_recipient_where;
 347           else if (c == '>')
 348             /* Discard the rest of this name that follows the `>'.  */
 349             {
 350               while (*field && *field != ',') ++field;
 351               if (! (*field++)) break; /* no comma */
 352               continue;
 353             }
 354           else
 355             *where++ = c;
 356         }
 357       if (the_list == NIL) break;
 358       field = the_list->string;
 359       the_list = the_list->continuation;
 360     }
 361   return where;
 362 }
 363 \f
 364 line_list
 365 make_file_preface ()
 366 {
 367   char *the_string, *temp;
 368   long idiotic_interface;
 369   struct tm *tm;
 370   long prefix_length;
 371   long user_length;
 372   long date_length;
 373   line_list result;
 374
 375   prefix_length = strlen (FROM_PREFIX);
 376   time (&idiotic_interface);
 377   /* Convert to a string, checking for out-of-range time stamps.
 378      Don't use 'ctime', as that might dump core if the hardware clock
 379      is set to a bizarre value.  */
 380   tm = localtime (&idiotic_interface);
 381   if (! (tm && TM_YEAR_IN_ASCTIME_RANGE (tm->tm_year)))
 382     fatal ("current time is out of range", 0);
 383   the_date = asctime (tm);
 384   /* the_date has an unwanted newline at the end */
 385   date_length = strlen (the_date) - 1;
 386   the_date[date_length] = '\0';
 387   temp = cuserid ((char *) NULL);
 388   user_length = strlen (temp);
 389   the_user = alloc_string (user_length + 1);
 390   strcpy (the_user, temp);
 391   the_string = alloc_string (3 + prefix_length
 392                              + user_length
 393                              + date_length);
 394   temp = the_string;
 395   strcpy (temp, FROM_PREFIX);
 396   temp = &temp[prefix_length];
 397   *temp++ = ' ';
 398   strcpy (temp, the_user);
 399   temp = &temp[user_length];
 400   *temp++ = ' ';
 401   strcpy (temp, the_date);
 402   result = new_list ();
 403   result->string = the_string;
 404   result->continuation = ((line_list) NULL);
 405   return result;
 406 }
 407
 408 void
 409 write_line_list (the_list, the_stream)
 410      register line_list the_list;
 411      FILE *the_stream;
 412 {
 413   for ( ;
 414       the_list != ((line_list) NULL) ;
 415       the_list = the_list->continuation)
 416     {
 417       fputs (the_list->string, the_stream);
 418       putc ('\n', the_stream);
 419     }
 420   return;
 421 }
 422 \f
 423 int
 424 close_the_streams ()
 425 {
 426   register stream_list rem;
 427   for (rem = the_streams;
 428        rem != ((stream_list) NULL);
 429        rem = rem->rest_streams)
 430     no_problems = (no_problems &&
 431                    ((*rem->action) (rem->handle) == 0));
 432   the_streams = ((stream_list) NULL);
 433   return (no_problems ? EXIT_SUCCESS : EXIT_FAILURE);
 434 }
 435
 436 void
 437 add_a_stream (the_stream, closing_action)
 438      FILE *the_stream;
 439      int (*closing_action)();
 440 {
 441   stream_list old = the_streams;
 442   the_streams = new_stream ();
 443   the_streams->handle = the_stream;
 444   the_streams->action = closing_action;
 445   the_streams->rest_streams = old;
 446   return;
 447 }
 448
 449 int
 450 my_fclose (the_file)
 451      FILE *the_file;
 452 {
 453   putc ('\n', the_file);
 454   fflush (the_file);
 455   return fclose (the_file);
 456 }
 457
 458 boolean
 459 open_a_file (name)
 460      char *name;
 461 {
 462   FILE *the_stream = fopen (name, "a");
 463   if (the_stream != ((FILE *) NULL))
 464     {
 465       add_a_stream (the_stream, my_fclose);
 466       if (the_user == ((char *) NULL))
 467         file_preface = make_file_preface ();
 468       write_line_list (file_preface, the_stream);
 469       return true;
 470     }
 471   return false;
 472 }
 473
 474 void
 475 put_string (s)
 476      char *s;
 477 {
 478   register stream_list rem;
 479   for (rem = the_streams;
 480        rem != ((stream_list) NULL);
 481        rem = rem->rest_streams)
 482     fputs (s, rem->handle);
 483   return;
 484 }
 485
 486 void
 487 put_line (string)
 488      char *string;
 489 {
 490   register stream_list rem;
 491   for (rem = the_streams;
 492        rem != ((stream_list) NULL);
 493        rem = rem->rest_streams)
 494     {
 495       char *s = string;
 496       int column = 0;
 497
 498       /* Divide STRING into lines.  */
 499       while (*s != 0)
 500         {
 501           char *breakpos;
 502
 503           /* Find the last char that fits.  */
 504           for (breakpos = s; *breakpos && column < 78; ++breakpos)
 505             {
 506               if (*breakpos == '\t')
 507                 column += 8;
 508               else
 509                 column++;
 510             }
 511           /* If we didn't reach end of line, break the line.  */
 512           if (*breakpos)
 513             {
 514               /* Back up to just after the last comma that fits.  */
 515               while (breakpos != s && breakpos[-1] != ',') --breakpos;
 516
 517               if (breakpos == s)
 518                 {
 519                   /* If no comma fits, move past the first address anyway.  */
 520                   while (*breakpos != 0 && *breakpos != ',') ++breakpos;
 521                   if (*breakpos != 0)
 522                     /* Include the comma after it.  */
 523                     ++breakpos;
 524                 }
 525             }
 526           /* Output that much, then break the line.  */
 527           fwrite (s, 1, breakpos - s, rem->handle);
 528           column = 8;
 529
 530           /* Skip whitespace and prepare to print more addresses.  */
 531           s = breakpos;
 532           while (*s == ' ' || *s == '\t') ++s;
 533           if (*s != 0)
 534             fputs ("\n\t", rem->handle);
 535         }
 536       putc ('\n', rem->handle);
 537     }
 538   return;
 539 }
 540 \f
 541 #define mail_error error
 542
 543 /* Handle an FCC field.  FIELD is the text of the first line (after
 544    the header name), and THE_LIST holds the continuation lines if any.
 545    Call open_a_file for each file.  */
 546
 547 void
 548 setup_files (the_list, field)
 549      register line_list the_list;
 550      register char *field;
 551 {
 552   register char *start;
 553   register char c;
 554   while (true)
 555     {
 556       while (((c = *field) != '\0')
 557              && (c == ' '
 558                  || c == '\t'
 559                  || c == ','))
 560         field += 1;
 561       if (c != '\0')
 562         {
 563           start = field;
 564           while (((c = *field) != '\0')
 565                  && c != ' '
 566                  && c != '\t'
 567                  && c != ',')
 568             field += 1;
 569           *field = '\0';
 570           if (!open_a_file (start))
 571             mail_error ("Could not open file %s", start);
 572           *field = c;
 573           if (c != '\0') continue;
 574         }
 575       if (the_list == ((line_list) NULL))
 576         return;
 577       field = the_list->string;
 578       the_list = the_list->continuation;
 579     }
 580 }
 581 \f
 582 /* Compute the total size of all recipient names stored in THE_HEADER.
 583    The result says how big to make the buffer to pass to parse_header.  */
 584
 585 int
 586 args_size (the_header)
 587      header the_header;
 588 {
 589   register header old = the_header;
 590   register line_list rem;
 591   register int size = 0;
 592   do
 593     {
 594       char *field;
 595       register char *keyword = get_keyword (the_header->text->string, &field);
 596       if ((strcmp (keyword, "TO") == 0)
 597           || (strcmp (keyword, "CC") == 0)
 598           || (strcmp (keyword, "BCC") == 0))
 599         {
 600           size += 1 + strlen (field);
 601           for (rem = the_header->text->continuation;
 602                rem != NIL;
 603                rem = rem->continuation)
 604             size += 1 + strlen (rem->string);
 605         }
 606       the_header = the_header->next;
 607     } while (the_header != old);
 608   return size;
 609 }
 610
 611 /* Scan the header described by the lists THE_HEADER,
 612    and put all recipient names into the buffer WHERE.
 613    Precede each recipient name with a space.
 614
 615    Also, if the header has any FCC fields, call setup_files for each one.  */
 616
 617 void
 618 parse_header (the_header, where)
 619      header the_header;
 620      register char *where;
 621 {
 622   register header old = the_header;
 623   do
 624     {
 625       char *field;
 626       register char *keyword = get_keyword (the_header->text->string, &field);
 627       if (strcmp (keyword, "TO") == 0)
 628         where = add_field (the_header->text->continuation, field, where);
 629       else if (strcmp (keyword, "CC") == 0)
 630         where = add_field (the_header->text->continuation, field, where);
 631       else if (strcmp (keyword, "BCC") == 0)
 632         {
 633           where = add_field (the_header->text->continuation, field, where);
 634           the_header->previous->next = the_header->next;
 635           the_header->next->previous = the_header->previous;
 636         }
 637       else if (strcmp (keyword, "FCC") == 0)
 638         setup_files (the_header->text->continuation, field);
 639       the_header = the_header->next;
 640     } while (the_header != old);
 641   *where = '\0';
 642   return;
 643 }
 644 \f
 645 /* Read lines from the input until we get a blank line.
 646    Create a list of `header' objects, one for each header field,
 647    each of which points to a list of `line_list' objects,
 648    one for each line in that field.
 649    Continuation lines are grouped in the headers they continue.  */
 650
 651 header
 652 read_header ()
 653 {
 654   register header the_header = ((header) NULL);
 655   register line_list *next_line = ((line_list *) NULL);
 656
 657   init_linebuffer (&lb);
 658
 659   do
 660     {
 661       long length;
 662       register char *line;
 663
 664       readline (&lb, stdin);
 665       line = lb.buffer;
 666       length = strlen (line);
 667       if (length == 0) break;
 668
 669       if (has_keyword (line))
 670         {
 671           register header old = the_header;
 672           the_header = new_header ();
 673           if (old == ((header) NULL))
 674             {
 675               the_header->next = the_header;
 676               the_header->previous = the_header;
 677             }
 678           else
 679             {
 680               the_header->previous = old;
 681               the_header->next = old->next;
 682               old->next = the_header;
 683             }
 684           next_line = &(the_header->text);
 685         }
 686
 687       if (next_line == ((line_list *) NULL))
 688         {
 689           /* Not a valid header */
 690           exit (EXIT_FAILURE);
 691         }
 692       *next_line = new_list ();
 693       (*next_line)->string = alloc_string (length);
 694       strcpy (((*next_line)->string), line);
 695       next_line = &((*next_line)->continuation);
 696       *next_line = NIL;
 697
 698     } while (true);
 699
 700   return the_header->next;
 701 }
 702 \f
 703 void
 704 write_header (the_header)
 705      header the_header;
 706 {
 707   register header old = the_header;
 708   do
 709     {
 710       register line_list the_list;
 711       for (the_list = the_header->text;
 712            the_list != NIL;
 713            the_list = the_list->continuation)
 714         put_line (the_list->string);
 715       the_header = the_header->next;
 716     } while (the_header != old);
 717   put_line ("");
 718   return;
 719 }
 720 \f
 721 int
 722 main (argc, argv)
 723      int argc;
 724      char **argv;
 725 {
 726   char *command_line;
 727   header the_header;
 728   long name_length;
 729   char *mail_program_name;
 730   char buf[BUFLEN + 1];
 731   register int size;
 732   FILE *the_pipe;
 733
 734   extern char *getenv ();
 735
 736   mail_program_name = getenv ("FAKEMAILER");
 737   if (!(mail_program_name && *mail_program_name))
 738     mail_program_name = MAIL_PROGRAM_NAME;
 739   name_length = strlen (mail_program_name);
 740
 741   my_name = MY_NAME;
 742   the_streams = ((stream_list) NULL);
 743   the_date = ((char *) NULL);
 744   the_user = ((char *) NULL);
 745
 746   the_header = read_header ();
 747   command_line = alloc_string (name_length + args_size (the_header));
 748   strcpy (command_line, mail_program_name);
 749   parse_header (the_header, &command_line[name_length]);
 750
 751   the_pipe = popen (command_line, "w");
 752   if (the_pipe == ((FILE *) NULL))
 753     fatal ("cannot open pipe to real mailer");
 754
 755   add_a_stream (the_pipe, pclose);
 756
 757   write_header (the_header);
 758
 759   /* Dump the message itself */
 760
 761   while (!feof (stdin))
 762     {
 763       size = fread (buf, 1, BUFLEN, stdin);
 764       buf[size] = '\0';
 765       put_string (buf);
 766     }
 767
 768   exit (close_the_streams ());
 769 }
 770
 771 #endif /* not MSDOS */
 772 #endif /* not BSD 4.2 (or newer) */
 773
 774 /* arch-tag: acb0afa6-315a-4c5b-b9e3-def5725c8783
 775    (do not change this comment) */
 776
 777 /* fakemail.c ends here */