lib-src/fakemail.c

   1 /* sendmail-like interface to /bin/mail for system V,
   2    Copyright (C) 1985, 1994, 1999, 2001, 2002, 2003, 2004,
   3                  2005, 2006, 2007, 2008, 2009, 2010, 2011  Free Software Foundation, Inc.
   4
   5 Author: Bill Rozas <jinx@martigny.ai.mit.edu>
   6 (according to ack.texi)
   7
   8 This file is part of GNU Emacs.
   9
  10 GNU Emacs is free software: you can redistribute it and/or modify
  11 it under the terms of the GNU General Public License as published by
  12 the Free Software Foundation, either version 3 of the License, or
  13 (at your option) any later version.
  14
  15 GNU Emacs is distributed in the hope that it will be useful,
  16 but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 GNU General Public License for more details.
  19
  20 You should have received a copy of the GNU General Public License
  21 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  22
  23
  24 #define _XOPEN_SOURCE 500       /* for cuserid */
  25
  26 #ifdef HAVE_CONFIG_H
  27 #include <config.h>
  28 #endif
  29
  30 #if defined (BSD_SYSTEM) && !defined (USE_FAKEMAIL)
  31 /* This program isnot used in BSD, so just avoid loader complaints.  */
  32 int
  33 main (void)
  34 {
  35   return 0;
  36 }
  37 #else /* not BSD 4.2 (or newer) */
  38 #ifdef MSDOS
  39 int
  40 main ()
  41 {
  42   return 0;
  43 }
  44 #else /* not MSDOS */
  45 /* This conditional contains all the rest of the file.  */
  46
  47 /* These are defined in config in some versions. */
  48
  49 #ifdef static
  50 #undef static
  51 #endif
  52
  53 #ifdef WINDOWSNT
  54 #include "ntlib.h"
  55 #endif
  56
  57 #include <stdio.h>
  58 #include <string.h>
  59 #include <ctype.h>
  60 #include <time.h>
  61 #include <pwd.h>
  62 #include <stdlib.h>
  63
  64 /* This is to declare cuserid.  */
  65 #include <unistd.h>
  66 \f
  67 /* Type definitions */
  68
  69 #define boolean int
  70 #define true 1
  71 #define false 0
  72
  73 #define TM_YEAR_BASE 1900
  74
  75 /* Nonzero if TM_YEAR is a struct tm's tm_year value that causes
  76    asctime to have well-defined behavior.  */
  77 #ifndef TM_YEAR_IN_ASCTIME_RANGE
  78 # define TM_YEAR_IN_ASCTIME_RANGE(tm_year) \
  79     (1000 - TM_YEAR_BASE <= (tm_year) && (tm_year) <= 9999 - TM_YEAR_BASE)
  80 #endif
  81
  82 /* Various lists */
  83
  84 struct line_record
  85 {
  86   char *string;
  87   struct line_record *continuation;
  88 };
  89 typedef struct line_record *line_list;
  90
  91 struct header_record
  92 {
  93   line_list text;
  94   struct header_record *next;
  95   struct header_record *previous;
  96 };
  97 typedef struct header_record *header;
  98
  99 struct stream_record
 100 {
 101   FILE *handle;
 102   int (*action)(FILE *);
 103   struct stream_record *rest_streams;
 104 };
 105 typedef struct stream_record *stream_list;
 106
 107 /* A `struct linebuffer' is a structure which holds a line of text.
 108  * `readline' reads a line from a stream into a linebuffer
 109  * and works regardless of the length of the line.
 110  */
 111
 112 struct linebuffer
 113 {
 114   long size;
 115   char *buffer;
 116 };
 117
 118 struct linebuffer lb;
 119
 120 #define new_list()                                      \
 121   ((line_list) xmalloc (sizeof (struct line_record)))
 122 #define new_header()                            \
 123   ((header) xmalloc (sizeof (struct header_record)))
 124 #define new_stream()                            \
 125   ((stream_list) xmalloc (sizeof (struct stream_record)))
 126 #define alloc_string(nchars)                            \
 127   ((char *) xmalloc ((nchars) + 1))
 128 \f
 129 /* Global declarations */
 130
 131 #define BUFLEN 1024
 132 #define KEYWORD_SIZE 256
 133 #define FROM_PREFIX "From"
 134 #define MY_NAME "fakemail"
 135 #define NIL ((line_list) NULL)
 136 #define INITIAL_LINE_SIZE 200
 137
 138 #ifndef MAIL_PROGRAM_NAME
 139 #define MAIL_PROGRAM_NAME "/bin/mail"
 140 #endif
 141
 142 static const char *my_name;
 143 static char *the_date;
 144 static char *the_user;
 145 static line_list file_preface;
 146 static stream_list the_streams;
 147 static boolean no_problems = true;
 148
 149 static void fatal (const char *s1) NO_RETURN;
 150
 151 #ifdef CURRENT_USER
 152 static struct passwd *my_entry;
 153 #define cuserid(s)                              \
 154 (my_entry = getpwuid (((int) geteuid ())),      \
 155  my_entry->pw_name)
 156 #endif
 157 \f
 158 /* Utilities */
 159
 160 /* Print error message.  `s1' is printf control string, `s2' is arg for it. */
 161
 162 static void
 163 error (const char *s1, const char *s2)
 164 {
 165   printf ("%s: ", my_name);
 166   printf (s1, s2);
 167   printf ("\n");
 168   no_problems = false;
 169 }
 170
 171 /* Print error message and exit.  */
 172
 173 static void
 174 fatal (const char *s1)
 175 {
 176   error ("%s", s1);
 177   exit (EXIT_FAILURE);
 178 }
 179
 180 /* Like malloc but get fatal error if memory is exhausted.  */
 181
 182 static long *
 183 xmalloc (int size)
 184 {
 185   long *result = (long *) malloc (((unsigned) size));
 186   if (result == ((long *) NULL))
 187     fatal ("virtual memory exhausted");
 188   return result;
 189 }
 190
 191 static long *
 192 xrealloc (long int *ptr, int size)
 193 {
 194   long *result = (long *) realloc (ptr, ((unsigned) size));
 195   if (result == ((long *) NULL))
 196     fatal ("virtual memory exhausted");
 197   return result;
 198 }
 199 \f
 200 /* Initialize a linebuffer for use */
 201
 202 void
 203 init_linebuffer (struct linebuffer *linebuffer)
 204 {
 205   linebuffer->size = INITIAL_LINE_SIZE;
 206   linebuffer->buffer = ((char *) xmalloc (INITIAL_LINE_SIZE));
 207 }
 208
 209 /* Read a line of text from `stream' into `linebuffer'.
 210    Return the length of the line.  */
 211
 212 long
 213 readline (struct linebuffer *linebuffer, FILE *stream)
 214 {
 215   char *buffer = linebuffer->buffer;
 216   char *p = linebuffer->buffer;
 217   char *end = p + linebuffer->size;
 218
 219   while (true)
 220     {
 221       int c = getc (stream);
 222       if (p == end)
 223         {
 224           linebuffer->size *= 2;
 225           buffer = ((char *) xrealloc ((long *)buffer, linebuffer->size));
 226           p = buffer + (p - linebuffer->buffer);
 227           end = buffer + linebuffer->size;
 228           linebuffer->buffer = buffer;
 229         }
 230       if (c < 0 || c == '\n')
 231         {
 232           *p = 0;
 233           break;
 234         }
 235       *p++ = c;
 236     }
 237
 238   return p - buffer;
 239 }
 240 \f
 241 /* Extract a colon-terminated keyword from the string FIELD.
 242    Return that keyword as a string stored in a static buffer.
 243    Store the address of the rest of the string into *REST.
 244
 245    If there is no keyword, return NULL and don't alter *REST.  */
 246
 247 char *
 248 get_keyword (register char *field, char **rest)
 249 {
 250   static char keyword[KEYWORD_SIZE];
 251   register char *ptr;
 252   register int c;
 253
 254   ptr = &keyword[0];
 255   c = (unsigned char) *field++;
 256   if (isspace (c) || c == ':')
 257     return ((char *) NULL);
 258   *ptr++ = (islower (c) ? toupper (c) : c);
 259   while (((c = (unsigned char) *field++) != ':') && ! isspace (c))
 260     *ptr++ = (islower (c) ? toupper (c) : c);
 261   *ptr++ = '\0';
 262   while (isspace (c))
 263     c = (unsigned char) *field++;
 264   if (c != ':')
 265     return ((char *) NULL);
 266   *rest = field;
 267   return &keyword[0];
 268 }
 269
 270 /* Nonzero if the string FIELD starts with a colon-terminated keyword.  */
 271
 272 boolean
 273 has_keyword (char *field)
 274 {
 275   char *ignored;
 276   return (get_keyword (field, &ignored) != ((char *) NULL));
 277 }
 278
 279 /* Store the string FIELD, followed by any lines in THE_LIST,
 280    into the buffer WHERE.
 281    Concatenate lines, putting just a space between them.
 282    Delete everything contained in parentheses.
 283    When a recipient name contains <...>, we discard
 284    everything except what is inside the <...>.
 285
 286    We don't pay attention to overflowing WHERE;
 287    the caller has to make it big enough.  */
 288
 289 char *
 290 add_field (line_list the_list, register char *field, register char *where)
 291 {
 292   register char c;
 293   while (true)
 294     {
 295       char *this_recipient_where;
 296       int in_quotes = 0;
 297
 298       *where++ = ' ';
 299       this_recipient_where = where;
 300
 301       while ((c = *field++) != '\0')
 302         {
 303           if (c == '\\')
 304             *where++ = c;
 305           else if (c == '"')
 306             {
 307               in_quotes = ! in_quotes;
 308               *where++ = c;
 309             }
 310           else if (in_quotes)
 311             *where++ = c;
 312           else if (c == '(')
 313             {
 314               while (*field && *field != ')') ++field;
 315               if (! (*field++)) break; /* no close */
 316               continue;
 317             }
 318           else if (c == ',')
 319             {
 320               *where++ = ' ';
 321               /* When we get to the end of one recipient,
 322                  don't discard it if the next one has <...>.  */
 323               this_recipient_where = where;
 324             }
 325           else if (c == '<')
 326             /* Discard everything we got before the `<'.  */
 327             where = this_recipient_where;
 328           else if (c == '>')
 329             /* Discard the rest of this name that follows the `>'.  */
 330             {
 331               while (*field && *field != ',') ++field;
 332               if (! (*field++)) break; /* no comma */
 333               continue;
 334             }
 335           else
 336             *where++ = c;
 337         }
 338       if (the_list == NIL) break;
 339       field = the_list->string;
 340       the_list = the_list->continuation;
 341     }
 342   return where;
 343 }
 344 \f
 345 line_list
 346 make_file_preface (void)
 347 {
 348   char *the_string, *temp;
 349   long idiotic_interface;
 350   struct tm *tm;
 351   long prefix_length;
 352   long user_length;
 353   long date_length;
 354   line_list result;
 355
 356   prefix_length = strlen (FROM_PREFIX);
 357   time (&idiotic_interface);
 358   /* Convert to a string, checking for out-of-range time stamps.
 359      Don't use 'ctime', as that might dump core if the hardware clock
 360      is set to a bizarre value.  */
 361   tm = localtime (&idiotic_interface);
 362   if (! (tm && TM_YEAR_IN_ASCTIME_RANGE (tm->tm_year)
 363          && (the_date = asctime (tm))))
 364     fatal ("current time is out of range");
 365   /* the_date has an unwanted newline at the end */
 366   date_length = strlen (the_date) - 1;
 367   the_date[date_length] = '\0';
 368   temp = cuserid ((char *) NULL);
 369   user_length = strlen (temp);
 370   the_user = alloc_string (user_length + 1);
 371   strcpy (the_user, temp);
 372   the_string = alloc_string (3 + prefix_length
 373                              + user_length
 374                              + date_length);
 375   temp = the_string;
 376   strcpy (temp, FROM_PREFIX);
 377   temp = &temp[prefix_length];
 378   *temp++ = ' ';
 379   strcpy (temp, the_user);
 380   temp = &temp[user_length];
 381   *temp++ = ' ';
 382   strcpy (temp, the_date);
 383   result = new_list ();
 384   result->string = the_string;
 385   result->continuation = ((line_list) NULL);
 386   return result;
 387 }
 388
 389 void
 390 write_line_list (register line_list the_list, FILE *the_stream)
 391 {
 392   for ( ;
 393       the_list != ((line_list) NULL) ;
 394       the_list = the_list->continuation)
 395     {
 396       fputs (the_list->string, the_stream);
 397       putc ('\n', the_stream);
 398     }
 399   return;
 400 }
 401 \f
 402 int
 403 close_the_streams (void)
 404 {
 405   register stream_list rem;
 406   for (rem = the_streams;
 407        rem != ((stream_list) NULL);
 408        rem = rem->rest_streams)
 409     no_problems = (no_problems &&
 410                    ((*rem->action) (rem->handle) == 0));
 411   the_streams = ((stream_list) NULL);
 412   return (no_problems ? EXIT_SUCCESS : EXIT_FAILURE);
 413 }
 414
 415 void
 416 add_a_stream (FILE *the_stream, int (*closing_action) (FILE *))
 417 {
 418   stream_list old = the_streams;
 419   the_streams = new_stream ();
 420   the_streams->handle = the_stream;
 421   the_streams->action = closing_action;
 422   the_streams->rest_streams = old;
 423   return;
 424 }
 425
 426 int
 427 my_fclose (FILE *the_file)
 428 {
 429   putc ('\n', the_file);
 430   fflush (the_file);
 431   return fclose (the_file);
 432 }
 433
 434 boolean
 435 open_a_file (char *name)
 436 {
 437   FILE *the_stream = fopen (name, "a");
 438   if (the_stream != ((FILE *) NULL))
 439     {
 440       add_a_stream (the_stream, my_fclose);
 441       if (the_user == ((char *) NULL))
 442         file_preface = make_file_preface ();
 443       write_line_list (file_preface, the_stream);
 444       return true;
 445     }
 446   return false;
 447 }
 448
 449 void
 450 put_string (char *s)
 451 {
 452   register stream_list rem;
 453   for (rem = the_streams;
 454        rem != ((stream_list) NULL);
 455        rem = rem->rest_streams)
 456     fputs (s, rem->handle);
 457   return;
 458 }
 459
 460 void
 461 put_line (const char *string)
 462 {
 463   register stream_list rem;
 464   for (rem = the_streams;
 465        rem != ((stream_list) NULL);
 466        rem = rem->rest_streams)
 467     {
 468       const char *s = string;
 469       int column = 0;
 470
 471       /* Divide STRING into lines.  */
 472       while (*s != 0)
 473         {
 474           const char *breakpos;
 475
 476           /* Find the last char that fits.  */
 477           for (breakpos = s; *breakpos && column < 78; ++breakpos)
 478             {
 479               if (*breakpos == '\t')
 480                 column += 8;
 481               else
 482                 column++;
 483             }
 484           /* If we didn't reach end of line, break the line.  */
 485           if (*breakpos)
 486             {
 487               /* Back up to just after the last comma that fits.  */
 488               while (breakpos != s && breakpos[-1] != ',') --breakpos;
 489
 490               if (breakpos == s)
 491                 {
 492                   /* If no comma fits, move past the first address anyway.  */
 493                   while (*breakpos != 0 && *breakpos != ',') ++breakpos;
 494                   if (*breakpos != 0)
 495                     /* Include the comma after it.  */
 496                     ++breakpos;
 497                 }
 498             }
 499           /* Output that much, then break the line.  */
 500           fwrite (s, 1, breakpos - s, rem->handle);
 501           column = 8;
 502
 503           /* Skip whitespace and prepare to print more addresses.  */
 504           s = breakpos;
 505           while (*s == ' ' || *s == '\t') ++s;
 506           if (*s != 0)
 507             fputs ("\n\t", rem->handle);
 508         }
 509       putc ('\n', rem->handle);
 510     }
 511   return;
 512 }
 513 \f
 514 #define mail_error error
 515
 516 /* Handle an FCC field.  FIELD is the text of the first line (after
 517    the header name), and THE_LIST holds the continuation lines if any.
 518    Call open_a_file for each file.  */
 519
 520 void
 521 setup_files (register line_list the_list, register char *field)
 522 {
 523   register char *start;
 524   register char c;
 525   while (true)
 526     {
 527       while (((c = *field) != '\0')
 528              && (c == ' '
 529                  || c == '\t'
 530                  || c == ','))
 531         field += 1;
 532       if (c != '\0')
 533         {
 534           start = field;
 535           while (((c = *field) != '\0')
 536                  && c != ' '
 537                  && c != '\t'
 538                  && c != ',')
 539             field += 1;
 540           *field = '\0';
 541           if (!open_a_file (start))
 542             mail_error ("Could not open file %s", start);
 543           *field = c;
 544           if (c != '\0') continue;
 545         }
 546       if (the_list == ((line_list) NULL))
 547         return;
 548       field = the_list->string;
 549       the_list = the_list->continuation;
 550     }
 551 }
 552 \f
 553 /* Compute the total size of all recipient names stored in THE_HEADER.
 554    The result says how big to make the buffer to pass to parse_header.  */
 555
 556 int
 557 args_size (header the_header)
 558 {
 559   register header old = the_header;
 560   register line_list rem;
 561   register int size = 0;
 562   do
 563     {
 564       char *field;
 565       register char *keyword = get_keyword (the_header->text->string, &field);
 566       if ((strcmp (keyword, "TO") == 0)
 567           || (strcmp (keyword, "CC") == 0)
 568           || (strcmp (keyword, "BCC") == 0))
 569         {
 570           size += 1 + strlen (field);
 571           for (rem = the_header->text->continuation;
 572                rem != NIL;
 573                rem = rem->continuation)
 574             size += 1 + strlen (rem->string);
 575         }
 576       the_header = the_header->next;
 577     } while (the_header != old);
 578   return size;
 579 }
 580
 581 /* Scan the header described by the lists THE_HEADER,
 582    and put all recipient names into the buffer WHERE.
 583    Precede each recipient name with a space.
 584
 585    Also, if the header has any FCC fields, call setup_files for each one.  */
 586
 587 void
 588 parse_header (header the_header, register char *where)
 589 {
 590   register header old = the_header;
 591   do
 592     {
 593       char *field;
 594       register char *keyword = get_keyword (the_header->text->string, &field);
 595       if (strcmp (keyword, "TO") == 0)
 596         where = add_field (the_header->text->continuation, field, where);
 597       else if (strcmp (keyword, "CC") == 0)
 598         where = add_field (the_header->text->continuation, field, where);
 599       else if (strcmp (keyword, "BCC") == 0)
 600         {
 601           where = add_field (the_header->text->continuation, field, where);
 602           the_header->previous->next = the_header->next;
 603           the_header->next->previous = the_header->previous;
 604         }
 605       else if (strcmp (keyword, "FCC") == 0)
 606         setup_files (the_header->text->continuation, field);
 607       the_header = the_header->next;
 608     } while (the_header != old);
 609   *where = '\0';
 610   return;
 611 }
 612 \f
 613 /* Read lines from the input until we get a blank line.
 614    Create a list of `header' objects, one for each header field,
 615    each of which points to a list of `line_list' objects,
 616    one for each line in that field.
 617    Continuation lines are grouped in the headers they continue.  */
 618
 619 header
 620 read_header (void)
 621 {
 622   register header the_header = ((header) NULL);
 623   register line_list *next_line = ((line_list *) NULL);
 624
 625   init_linebuffer (&lb);
 626
 627   do
 628     {
 629       long length;
 630       register char *line;
 631
 632       readline (&lb, stdin);
 633       line = lb.buffer;
 634       length = strlen (line);
 635       if (length == 0) break;
 636
 637       if (has_keyword (line))
 638         {
 639           register header old = the_header;
 640           the_header = new_header ();
 641           if (old == ((header) NULL))
 642             {
 643               the_header->next = the_header;
 644               the_header->previous = the_header;
 645             }
 646           else
 647             {
 648               the_header->previous = old;
 649               the_header->next = old->next;
 650               old->next = the_header;
 651             }
 652           next_line = &(the_header->text);
 653         }
 654
 655       if (next_line == ((line_list *) NULL))
 656         {
 657           /* Not a valid header */
 658           exit (EXIT_FAILURE);
 659         }
 660       *next_line = new_list ();
 661       (*next_line)->string = alloc_string (length);
 662       strcpy (((*next_line)->string), line);
 663       next_line = &((*next_line)->continuation);
 664       *next_line = NIL;
 665
 666     } while (true);
 667
 668   if (! the_header)
 669     fatal ("input message has no header");
 670   return the_header->next;
 671 }
 672 \f
 673 void
 674 write_header (header the_header)
 675 {
 676   register header old = the_header;
 677   do
 678     {
 679       register line_list the_list;
 680       for (the_list = the_header->text;
 681            the_list != NIL;
 682            the_list = the_list->continuation)
 683         put_line (the_list->string);
 684       the_header = the_header->next;
 685     } while (the_header != old);
 686   put_line ("");
 687   return;
 688 }
 689 \f
 690 int
 691 main (int argc, char **argv)
 692 {
 693   char *command_line;
 694   header the_header;
 695   long name_length;
 696   const char *mail_program_name;
 697   char buf[BUFLEN + 1];
 698   register int size;
 699   FILE *the_pipe;
 700
 701   mail_program_name = getenv ("FAKEMAILER");
 702   if (!(mail_program_name && *mail_program_name))
 703     mail_program_name = MAIL_PROGRAM_NAME;
 704   name_length = strlen (mail_program_name);
 705
 706   my_name = MY_NAME;
 707   the_streams = ((stream_list) NULL);
 708   the_date = ((char *) NULL);
 709   the_user = ((char *) NULL);
 710
 711   the_header = read_header ();
 712   command_line = alloc_string (name_length + args_size (the_header));
 713   strcpy (command_line, mail_program_name);
 714   parse_header (the_header, &command_line[name_length]);
 715
 716   the_pipe = popen (command_line, "w");
 717   if (the_pipe == ((FILE *) NULL))
 718     fatal ("cannot open pipe to real mailer");
 719
 720   add_a_stream (the_pipe, pclose);
 721
 722   write_header (the_header);
 723
 724   /* Dump the message itself */
 725
 726   while (!feof (stdin))
 727     {
 728       size = fread (buf, 1, BUFLEN, stdin);
 729       buf[size] = '\0';
 730       put_string (buf);
 731     }
 732
 733   exit (close_the_streams ());
 734 }
 735
 736 #endif /* not MSDOS */
 737 #endif /* not BSD 4.2 (or newer) */
 738
 739
 740 /* fakemail.c ends here */