lib-src/fakemail.c

   1 /* sendmail-like interface to /bin/mail for system V,
   2    Copyright (C) 1985, 1994, 1999, 2001-2011  Free Software Foundation, Inc.
   3
   4 Author: Bill Rozas <jinx@martigny.ai.mit.edu>
   5 (according to ack.texi)
   6
   7 This file is part of GNU Emacs.
   8
   9 GNU Emacs is free software: you can redistribute it and/or modify
  10 it under the terms of the GNU General Public License as published by
  11 the Free Software Foundation, either version 3 of the License, or
  12 (at your option) any later version.
  13
  14 GNU Emacs is distributed in the hope that it will be useful,
  15 but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 GNU General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22
  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 (USE_FAKEMAIL)
  30 /* This program isnot used in BSD, so just avoid loader complaints.  */
  31 int
  32 main (void)
  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 <stdio.h>
  57 #include <string.h>
  58 #include <ctype.h>
  59 #include <time.h>
  60 #include <pwd.h>
  61 #include <stdlib.h>
  62
  63 /* This is to declare cuserid.  */
  64 #include <unistd.h>
  65 \f
  66 /* Type definitions */
  67
  68 #define boolean int
  69 #define true 1
  70 #define false 0
  71
  72 #define TM_YEAR_BASE 1900
  73
  74 /* Nonzero if TM_YEAR is a struct tm's tm_year value that causes
  75    asctime to have well-defined behavior.  */
  76 #ifndef TM_YEAR_IN_ASCTIME_RANGE
  77 # define TM_YEAR_IN_ASCTIME_RANGE(tm_year) \
  78     (1000 - TM_YEAR_BASE <= (tm_year) && (tm_year) <= 9999 - TM_YEAR_BASE)
  79 #endif
  80
  81 /* Various lists */
  82
  83 struct line_record
  84 {
  85   char *string;
  86   struct line_record *continuation;
  87 };
  88 typedef struct line_record *line_list;
  89
  90 struct header_record
  91 {
  92   line_list text;
  93   struct header_record *next;
  94   struct header_record *previous;
  95 };
  96 typedef struct header_record *header;
  97
  98 struct stream_record
  99 {
 100   FILE *handle;
 101   int (*action)(FILE *);
 102   struct stream_record *rest_streams;
 103 };
 104 typedef struct stream_record *stream_list;
 105
 106 /* A `struct linebuffer' is a structure which holds a line of text.
 107  * `readline' reads a line from a stream into a linebuffer
 108  * and works regardless of the length of the line.
 109  */
 110
 111 struct linebuffer
 112 {
 113   long size;
 114   char *buffer;
 115 };
 116
 117 struct linebuffer lb;
 118
 119 #define new_list()                                      \
 120   ((line_list) xmalloc (sizeof (struct line_record)))
 121 #define new_header()                            \
 122   ((header) xmalloc (sizeof (struct header_record)))
 123 #define new_stream()                            \
 124   ((stream_list) xmalloc (sizeof (struct stream_record)))
 125 #define alloc_string(nchars)                            \
 126   ((char *) xmalloc ((nchars) + 1))
 127 \f
 128 /* Global declarations */
 129
 130 #define BUFLEN 1024
 131 #define KEYWORD_SIZE 256
 132 #define FROM_PREFIX "From"
 133 #define MY_NAME "fakemail"
 134 #define NIL ((line_list) NULL)
 135 #define INITIAL_LINE_SIZE 200
 136
 137 #ifndef MAIL_PROGRAM_NAME
 138 #define MAIL_PROGRAM_NAME "/bin/mail"
 139 #endif
 140
 141 static const char *my_name;
 142 static char *the_date;
 143 static char *the_user;
 144 static line_list file_preface;
 145 static stream_list the_streams;
 146 static boolean no_problems = true;
 147
 148 static void fatal (const char *s1) NO_RETURN;
 149
 150 #ifdef CURRENT_USER
 151 static struct passwd *my_entry;
 152 #define cuserid(s)                              \
 153 (my_entry = getpwuid (((int) geteuid ())),      \
 154  my_entry->pw_name)
 155 #endif
 156 \f
 157 /* Utilities */
 158
 159 /* Print error message.  `s1' is printf control string, `s2' is arg for it. */
 160
 161 static void
 162 error (const char *s1, const char *s2)
 163 {
 164   printf ("%s: ", my_name);
 165   printf (s1, s2);
 166   printf ("\n");
 167   no_problems = false;
 168 }
 169
 170 /* Print error message and exit.  */
 171
 172 static void
 173 fatal (const char *s1)
 174 {
 175   error ("%s", s1);
 176   exit (EXIT_FAILURE);
 177 }
 178
 179 /* Like malloc but get fatal error if memory is exhausted.  */
 180
 181 static void *
 182 xmalloc (size_t size)
 183 {
 184   void *result = malloc (size);
 185   if (! result)
 186     fatal ("virtual memory exhausted");
 187   return result;
 188 }
 189
 190 static void *
 191 xrealloc (void *ptr, size_t size)
 192 {
 193   void *result = realloc (ptr, size);
 194   if (! result)
 195     fatal ("virtual memory exhausted");
 196   return result;
 197 }
 198 \f
 199 /* Initialize a linebuffer for use */
 200
 201 static void
 202 init_linebuffer (struct linebuffer *linebuffer)
 203 {
 204   linebuffer->size = INITIAL_LINE_SIZE;
 205   linebuffer->buffer = ((char *) xmalloc (INITIAL_LINE_SIZE));
 206 }
 207
 208 /* Read a line of text from `stream' into `linebuffer'.
 209    Return the length of the line.  */
 210
 211 static long
 212 readline (struct linebuffer *linebuffer, FILE *stream)
 213 {
 214   char *buffer = linebuffer->buffer;
 215   char *p = linebuffer->buffer;
 216   char *end = p + linebuffer->size;
 217
 218   while (true)
 219     {
 220       int c = getc (stream);
 221       if (p == end)
 222         {
 223           linebuffer->size *= 2;
 224           buffer = (char *) xrealloc (buffer, linebuffer->size);
 225           p = buffer + (p - linebuffer->buffer);
 226           end = buffer + linebuffer->size;
 227           linebuffer->buffer = buffer;
 228         }
 229       if (c < 0 || c == '\n')
 230         {
 231           *p = 0;
 232           break;
 233         }
 234       *p++ = c;
 235     }
 236
 237   return p - buffer;
 238 }
 239 \f
 240 /* Extract a colon-terminated keyword from the string FIELD.
 241    Return that keyword as a string stored in a static buffer.
 242    Store the address of the rest of the string into *REST.
 243
 244    If there is no keyword, return NULL and don't alter *REST.  */
 245
 246 static char *
 247 get_keyword (register char *field, char **rest)
 248 {
 249   static char keyword[KEYWORD_SIZE];
 250   register char *ptr;
 251   register int c;
 252
 253   ptr = &keyword[0];
 254   c = (unsigned char) *field++;
 255   if (isspace (c) || c == ':')
 256     return ((char *) NULL);
 257   *ptr++ = (islower (c) ? toupper (c) : c);
 258   while (((c = (unsigned char) *field++) != ':') && ! isspace (c))
 259     *ptr++ = (islower (c) ? toupper (c) : c);
 260   *ptr++ = '\0';
 261   while (isspace (c))
 262     c = (unsigned char) *field++;
 263   if (c != ':')
 264     return ((char *) NULL);
 265   *rest = field;
 266   return &keyword[0];
 267 }
 268
 269 /* Nonzero if the string FIELD starts with a colon-terminated keyword.  */
 270
 271 static boolean
 272 has_keyword (char *field)
 273 {
 274   char *ignored;
 275   return (get_keyword (field, &ignored) != ((char *) NULL));
 276 }
 277
 278 /* Store the string FIELD, followed by any lines in THE_LIST,
 279    into the buffer WHERE.
 280    Concatenate lines, putting just a space between them.
 281    Delete everything contained in parentheses.
 282    When a recipient name contains <...>, we discard
 283    everything except what is inside the <...>.
 284
 285    We don't pay attention to overflowing WHERE;
 286    the caller has to make it big enough.  */
 287
 288 static char *
 289 add_field (line_list the_list, register char *field, register char *where)
 290 {
 291   register char c;
 292   while (true)
 293     {
 294       char *this_recipient_where;
 295       int in_quotes = 0;
 296
 297       *where++ = ' ';
 298       this_recipient_where = where;
 299
 300       while ((c = *field++) != '\0')
 301         {
 302           if (c == '\\')
 303             *where++ = c;
 304           else if (c == '"')
 305             {
 306               in_quotes = ! in_quotes;
 307               *where++ = c;
 308             }
 309           else if (in_quotes)
 310             *where++ = c;
 311           else if (c == '(')
 312             {
 313               while (*field && *field != ')') ++field;
 314               if (! (*field++)) break; /* no close */
 315               continue;
 316             }
 317           else if (c == ',')
 318             {
 319               *where++ = ' ';
 320               /* When we get to the end of one recipient,
 321                  don't discard it if the next one has <...>.  */
 322               this_recipient_where = where;
 323             }
 324           else if (c == '<')
 325             /* Discard everything we got before the `<'.  */
 326             where = this_recipient_where;
 327           else if (c == '>')
 328             /* Discard the rest of this name that follows the `>'.  */
 329             {
 330               while (*field && *field != ',') ++field;
 331               if (! (*field++)) break; /* no comma */
 332               continue;
 333             }
 334           else
 335             *where++ = c;
 336         }
 337       if (the_list == NIL) break;
 338       field = the_list->string;
 339       the_list = the_list->continuation;
 340     }
 341   return where;
 342 }
 343 \f
 344 static line_list
 345 make_file_preface (void)
 346 {
 347   char *the_string, *temp;
 348   long idiotic_interface;
 349   struct tm *tm;
 350   long prefix_length;
 351   long user_length;
 352   long date_length;
 353   line_list result;
 354
 355   prefix_length = strlen (FROM_PREFIX);
 356   time (&idiotic_interface);
 357   /* Convert to a string, checking for out-of-range time stamps.
 358      Don't use 'ctime', as that might dump core if the hardware clock
 359      is set to a bizarre value.  */
 360   tm = localtime (&idiotic_interface);
 361   if (! (tm && TM_YEAR_IN_ASCTIME_RANGE (tm->tm_year)
 362          && (the_date = asctime (tm))))
 363     fatal ("current time is out of range");
 364   /* the_date has an unwanted newline at the end */
 365   date_length = strlen (the_date) - 1;
 366   the_date[date_length] = '\0';
 367   temp = cuserid ((char *) NULL);
 368   user_length = strlen (temp);
 369   the_user = alloc_string (user_length + 1);
 370   strcpy (the_user, temp);
 371   the_string = alloc_string (3 + prefix_length
 372                              + user_length
 373                              + date_length);
 374   temp = the_string;
 375   strcpy (temp, FROM_PREFIX);
 376   temp = &temp[prefix_length];
 377   *temp++ = ' ';
 378   strcpy (temp, the_user);
 379   temp = &temp[user_length];
 380   *temp++ = ' ';
 381   strcpy (temp, the_date);
 382   result = new_list ();
 383   result->string = the_string;
 384   result->continuation = ((line_list) NULL);
 385   return result;
 386 }
 387
 388 static void
 389 write_line_list (register line_list the_list, FILE *the_stream)
 390 {
 391   for ( ;
 392       the_list != ((line_list) NULL) ;
 393       the_list = the_list->continuation)
 394     {
 395       fputs (the_list->string, the_stream);
 396       putc ('\n', the_stream);
 397     }
 398   return;
 399 }
 400 \f
 401 static int
 402 close_the_streams (void)
 403 {
 404   register stream_list rem;
 405   for (rem = the_streams;
 406        rem != ((stream_list) NULL);
 407        rem = rem->rest_streams)
 408     if (no_problems && (*rem->action) (rem->handle) != 0)
 409       error ("output error", NULL);
 410   the_streams = ((stream_list) NULL);
 411   return (no_problems ? EXIT_SUCCESS : EXIT_FAILURE);
 412 }
 413
 414 static void
 415 add_a_stream (FILE *the_stream, int (*closing_action) (FILE *))
 416 {
 417   stream_list old = the_streams;
 418   the_streams = new_stream ();
 419   the_streams->handle = the_stream;
 420   the_streams->action = closing_action;
 421   the_streams->rest_streams = old;
 422   return;
 423 }
 424
 425 static int
 426 my_fclose (FILE *the_file)
 427 {
 428   putc ('\n', the_file);
 429   fflush (the_file);
 430   if (ferror (the_file))
 431     return EOF;
 432   return fclose (the_file);
 433 }
 434
 435 static boolean
 436 open_a_file (char *name)
 437 {
 438   FILE *the_stream = fopen (name, "a");
 439   if (the_stream != ((FILE *) NULL))
 440     {
 441       add_a_stream (the_stream, my_fclose);
 442       if (the_user == ((char *) NULL))
 443         file_preface = make_file_preface ();
 444       write_line_list (file_preface, the_stream);
 445       return true;
 446     }
 447   return false;
 448 }
 449
 450 static void
 451 put_string (char *s)
 452 {
 453   register stream_list rem;
 454   for (rem = the_streams;
 455        rem != ((stream_list) NULL);
 456        rem = rem->rest_streams)
 457     fputs (s, rem->handle);
 458   return;
 459 }
 460
 461 static void
 462 put_line (const char *string)
 463 {
 464   register stream_list rem;
 465   for (rem = the_streams;
 466        rem != ((stream_list) NULL);
 467        rem = rem->rest_streams)
 468     {
 469       const char *s = string;
 470       int column = 0;
 471
 472       /* Divide STRING into lines.  */
 473       while (*s != 0)
 474         {
 475           const char *breakpos;
 476
 477           /* Find the last char that fits.  */
 478           for (breakpos = s; *breakpos && column < 78; ++breakpos)
 479             {
 480               if (*breakpos == '\t')
 481                 column += 8;
 482               else
 483                 column++;
 484             }
 485           /* If we didn't reach end of line, break the line.  */
 486           if (*breakpos)
 487             {
 488               /* Back up to just after the last comma that fits.  */
 489               while (breakpos != s && breakpos[-1] != ',') --breakpos;
 490
 491               if (breakpos == s)
 492                 {
 493                   /* If no comma fits, move past the first address anyway.  */
 494                   while (*breakpos != 0 && *breakpos != ',') ++breakpos;
 495                   if (*breakpos != 0)
 496                     /* Include the comma after it.  */
 497                     ++breakpos;
 498                 }
 499             }
 500           /* Output that much, then break the line.  */
 501           fwrite (s, 1, breakpos - s, rem->handle);
 502           column = 8;
 503
 504           /* Skip whitespace and prepare to print more addresses.  */
 505           s = breakpos;
 506           while (*s == ' ' || *s == '\t') ++s;
 507           if (*s != 0)
 508             fputs ("\n\t", rem->handle);
 509         }
 510       putc ('\n', rem->handle);
 511     }
 512   return;
 513 }
 514 \f
 515 #define mail_error error
 516
 517 /* Handle an FCC field.  FIELD is the text of the first line (after
 518    the header name), and THE_LIST holds the continuation lines if any.
 519    Call open_a_file for each file.  */
 520
 521 static void
 522 setup_files (register line_list the_list, register char *field)
 523 {
 524   register char *start;
 525   register char c;
 526   while (true)
 527     {
 528       while (((c = *field) != '\0')
 529              && (c == ' '
 530                  || c == '\t'
 531                  || c == ','))
 532         field += 1;
 533       if (c != '\0')
 534         {
 535           start = field;
 536           while (((c = *field) != '\0')
 537                  && c != ' '
 538                  && c != '\t'
 539                  && c != ',')
 540             field += 1;
 541           *field = '\0';
 542           if (!open_a_file (start))
 543             mail_error ("Could not open file %s", start);
 544           *field = c;
 545           if (c != '\0') continue;
 546         }
 547       if (the_list == ((line_list) NULL))
 548         return;
 549       field = the_list->string;
 550       the_list = the_list->continuation;
 551     }
 552 }
 553 \f
 554 /* Compute the total size of all recipient names stored in THE_HEADER.
 555    The result says how big to make the buffer to pass to parse_header.  */
 556
 557 static int
 558 args_size (header the_header)
 559 {
 560   register header old = the_header;
 561   register line_list rem;
 562   register int size = 0;
 563   do
 564     {
 565       char *field;
 566       register char *keyword = get_keyword (the_header->text->string, &field);
 567       if ((strcmp (keyword, "TO") == 0)
 568           || (strcmp (keyword, "CC") == 0)
 569           || (strcmp (keyword, "BCC") == 0))
 570         {
 571           size += 1 + strlen (field);
 572           for (rem = the_header->text->continuation;
 573                rem != NIL;
 574                rem = rem->continuation)
 575             size += 1 + strlen (rem->string);
 576         }
 577       the_header = the_header->next;
 578     } while (the_header != old);
 579   return size;
 580 }
 581
 582 /* Scan the header described by the lists THE_HEADER,
 583    and put all recipient names into the buffer WHERE.
 584    Precede each recipient name with a space.
 585
 586    Also, if the header has any FCC fields, call setup_files for each one.  */
 587
 588 static void
 589 parse_header (header the_header, register char *where)
 590 {
 591   register header old = the_header;
 592   do
 593     {
 594       char *field;
 595       register char *keyword = get_keyword (the_header->text->string, &field);
 596       if (strcmp (keyword, "TO") == 0)
 597         where = add_field (the_header->text->continuation, field, where);
 598       else if (strcmp (keyword, "CC") == 0)
 599         where = add_field (the_header->text->continuation, field, where);
 600       else if (strcmp (keyword, "BCC") == 0)
 601         {
 602           where = add_field (the_header->text->continuation, field, where);
 603           the_header->previous->next = the_header->next;
 604           the_header->next->previous = the_header->previous;
 605         }
 606       else if (strcmp (keyword, "FCC") == 0)
 607         setup_files (the_header->text->continuation, field);
 608       the_header = the_header->next;
 609     } while (the_header != old);
 610   *where = '\0';
 611   return;
 612 }
 613 \f
 614 /* Read lines from the input until we get a blank line.
 615    Create a list of `header' objects, one for each header field,
 616    each of which points to a list of `line_list' objects,
 617    one for each line in that field.
 618    Continuation lines are grouped in the headers they continue.  */
 619
 620 static header
 621 read_header (void)
 622 {
 623   register header the_header = ((header) NULL);
 624   register line_list *next_line = ((line_list *) NULL);
 625
 626   init_linebuffer (&lb);
 627
 628   do
 629     {
 630       long length;
 631       register char *line;
 632
 633       readline (&lb, stdin);
 634       line = lb.buffer;
 635       length = strlen (line);
 636       if (length == 0) break;
 637
 638       if (has_keyword (line))
 639         {
 640           register header old = the_header;
 641           the_header = new_header ();
 642           if (old == ((header) NULL))
 643             {
 644               the_header->next = the_header;
 645               the_header->previous = the_header;
 646             }
 647           else
 648             {
 649               the_header->previous = old;
 650               the_header->next = old->next;
 651               old->next = the_header;
 652             }
 653           next_line = &(the_header->text);
 654         }
 655
 656       if (next_line == ((line_list *) NULL))
 657         {
 658           /* Not a valid header */
 659           exit (EXIT_FAILURE);
 660         }
 661       *next_line = new_list ();
 662       (*next_line)->string = alloc_string (length);
 663       strcpy (((*next_line)->string), line);
 664       next_line = &((*next_line)->continuation);
 665       *next_line = NIL;
 666
 667     } while (true);
 668
 669   if (! the_header)
 670     fatal ("input message has no header");
 671   return the_header->next;
 672 }
 673 \f
 674 static void
 675 write_header (header the_header)
 676 {
 677   register header old = the_header;
 678   do
 679     {
 680       register line_list the_list;
 681       for (the_list = the_header->text;
 682            the_list != NIL;
 683            the_list = the_list->continuation)
 684         put_line (the_list->string);
 685       the_header = the_header->next;
 686     } while (the_header != old);
 687   put_line ("");
 688   return;
 689 }
 690 \f
 691 int
 692 main (int argc, char **argv)
 693 {
 694   char *command_line;
 695   header the_header;
 696   long name_length;
 697   const char *mail_program_name;
 698   char buf[BUFLEN + 1];
 699   register int size;
 700   FILE *the_pipe;
 701
 702   mail_program_name = getenv ("FAKEMAILER");
 703   if (!(mail_program_name && *mail_program_name))
 704     mail_program_name = MAIL_PROGRAM_NAME;
 705   name_length = strlen (mail_program_name);
 706
 707   my_name = MY_NAME;
 708   the_streams = ((stream_list) NULL);
 709   the_date = ((char *) NULL);
 710   the_user = ((char *) NULL);
 711
 712   the_header = read_header ();
 713   command_line = alloc_string (name_length + args_size (the_header));
 714   strcpy (command_line, mail_program_name);
 715   parse_header (the_header, &command_line[name_length]);
 716
 717   the_pipe = popen (command_line, "w");
 718   if (the_pipe == ((FILE *) NULL))
 719     fatal ("cannot open pipe to real mailer");
 720
 721   add_a_stream (the_pipe, pclose);
 722
 723   write_header (the_header);
 724
 725   /* Dump the message itself */
 726
 727   while (!feof (stdin))
 728     {
 729       size = fread (buf, 1, BUFLEN, stdin);
 730       buf[size] = '\0';
 731       put_string (buf);
 732     }
 733
 734   if (no_problems && (ferror (stdin) || fclose (stdin) != 0))
 735     error ("input error", NULL);
 736
 737   exit (close_the_streams ());
 738 }
 739
 740 #endif /* not MSDOS */
 741 #endif /* not BSD 4.2 (or newer) */
 742
 743
 744 /* fakemail.c ends here */