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  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 #ifdef HAVE_UNISTD_H
  66 #include <unistd.h>
  67 #endif
  68 \f
  69 /* Type definitions */
  70
  71 #define boolean int
  72 #define true 1
  73 #define false 0
  74
  75 #define TM_YEAR_BASE 1900
  76
  77 /* Nonzero if TM_YEAR is a struct tm's tm_year value that causes
  78    asctime to have well-defined behavior.  */
  79 #ifndef TM_YEAR_IN_ASCTIME_RANGE
  80 # define TM_YEAR_IN_ASCTIME_RANGE(tm_year) \
  81     (1000 - TM_YEAR_BASE <= (tm_year) && (tm_year) <= 9999 - TM_YEAR_BASE)
  82 #endif
  83
  84 /* Various lists */
  85
  86 struct line_record
  87 {
  88   char *string;
  89   struct line_record *continuation;
  90 };
  91 typedef struct line_record *line_list;
  92
  93 struct header_record
  94 {
  95   line_list text;
  96   struct header_record *next;
  97   struct header_record *previous;
  98 };
  99 typedef struct header_record *header;
 100
 101 struct stream_record
 102 {
 103   FILE *handle;
 104   int (*action)(FILE *);
 105   struct stream_record *rest_streams;
 106 };
 107 typedef struct stream_record *stream_list;
 108
 109 /* A `struct linebuffer' is a structure which holds a line of text.
 110  * `readline' reads a line from a stream into a linebuffer
 111  * and works regardless of the length of the line.
 112  */
 113
 114 struct linebuffer
 115 {
 116   long size;
 117   char *buffer;
 118 };
 119
 120 struct linebuffer lb;
 121
 122 #define new_list()                                      \
 123   ((line_list) xmalloc (sizeof (struct line_record)))
 124 #define new_header()                            \
 125   ((header) xmalloc (sizeof (struct header_record)))
 126 #define new_stream()                            \
 127   ((stream_list) xmalloc (sizeof (struct stream_record)))
 128 #define alloc_string(nchars)                            \
 129   ((char *) xmalloc ((nchars) + 1))
 130 \f
 131 /* Global declarations */
 132
 133 #define BUFLEN 1024
 134 #define KEYWORD_SIZE 256
 135 #define FROM_PREFIX "From"
 136 #define MY_NAME "fakemail"
 137 #define NIL ((line_list) NULL)
 138 #define INITIAL_LINE_SIZE 200
 139
 140 #ifndef MAIL_PROGRAM_NAME
 141 #define MAIL_PROGRAM_NAME "/bin/mail"
 142 #endif
 143
 144 static const char *my_name;
 145 static char *the_date;
 146 static char *the_user;
 147 static line_list file_preface;
 148 static stream_list the_streams;
 149 static boolean no_problems = true;
 150
 151 static void fatal (const char *s1) NO_RETURN;
 152
 153 #ifdef CURRENT_USER
 154 static struct passwd *my_entry;
 155 #define cuserid(s)                              \
 156 (my_entry = getpwuid (((int) geteuid ())),      \
 157  my_entry->pw_name)
 158 #endif
 159 \f
 160 /* Utilities */
 161
 162 /* Print error message.  `s1' is printf control string, `s2' is arg for it. */
 163
 164 static void
 165 error (const char *s1, const char *s2)
 166 {
 167   printf ("%s: ", my_name);
 168   printf (s1, s2);
 169   printf ("\n");
 170   no_problems = false;
 171 }
 172
 173 /* Print error message and exit.  */
 174
 175 static void
 176 fatal (const char *s1)
 177 {
 178   error ("%s", s1);
 179   exit (EXIT_FAILURE);
 180 }
 181
 182 /* Like malloc but get fatal error if memory is exhausted.  */
 183
 184 static long *
 185 xmalloc (int size)
 186 {
 187   long *result = (long *) malloc (((unsigned) size));
 188   if (result == ((long *) NULL))
 189     fatal ("virtual memory exhausted");
 190   return result;
 191 }
 192
 193 static long *
 194 xrealloc (long int *ptr, int size)
 195 {
 196   long *result = (long *) realloc (ptr, ((unsigned) size));
 197   if (result == ((long *) NULL))
 198     fatal ("virtual memory exhausted");
 199   return result;
 200 }
 201 \f
 202 /* Initialize a linebuffer for use */
 203
 204 void
 205 init_linebuffer (struct linebuffer *linebuffer)
 206 {
 207   linebuffer->size = INITIAL_LINE_SIZE;
 208   linebuffer->buffer = ((char *) xmalloc (INITIAL_LINE_SIZE));
 209 }
 210
 211 /* Read a line of text from `stream' into `linebuffer'.
 212    Return the length of the line.  */
 213
 214 long
 215 readline (struct linebuffer *linebuffer, FILE *stream)
 216 {
 217   char *buffer = linebuffer->buffer;
 218   char *p = linebuffer->buffer;
 219   char *end = p + linebuffer->size;
 220
 221   while (true)
 222     {
 223       int c = getc (stream);
 224       if (p == end)
 225         {
 226           linebuffer->size *= 2;
 227           buffer = ((char *) xrealloc ((long *)buffer, linebuffer->size));
 228           p = buffer + (p - linebuffer->buffer);
 229           end = buffer + linebuffer->size;
 230           linebuffer->buffer = buffer;
 231         }
 232       if (c < 0 || c == '\n')
 233         {
 234           *p = 0;
 235           break;
 236         }
 237       *p++ = c;
 238     }
 239
 240   return p - buffer;
 241 }
 242 \f
 243 /* Extract a colon-terminated keyword from the string FIELD.
 244    Return that keyword as a string stored in a static buffer.
 245    Store the address of the rest of the string into *REST.
 246
 247    If there is no keyword, return NULL and don't alter *REST.  */
 248
 249 char *
 250 get_keyword (register char *field, char **rest)
 251 {
 252   static char keyword[KEYWORD_SIZE];
 253   register char *ptr;
 254   register int c;
 255
 256   ptr = &keyword[0];
 257   c = (unsigned char) *field++;
 258   if (isspace (c) || c == ':')
 259     return ((char *) NULL);
 260   *ptr++ = (islower (c) ? toupper (c) : c);
 261   while (((c = (unsigned char) *field++) != ':') && ! isspace (c))
 262     *ptr++ = (islower (c) ? toupper (c) : c);
 263   *ptr++ = '\0';
 264   while (isspace (c))
 265     c = (unsigned char) *field++;
 266   if (c != ':')
 267     return ((char *) NULL);
 268   *rest = field;
 269   return &keyword[0];
 270 }
 271
 272 /* Nonzero if the string FIELD starts with a colon-terminated keyword.  */
 273
 274 boolean
 275 has_keyword (char *field)
 276 {
 277   char *ignored;
 278   return (get_keyword (field, &ignored) != ((char *) NULL));
 279 }
 280
 281 /* Store the string FIELD, followed by any lines in THE_LIST,
 282    into the buffer WHERE.
 283    Concatenate lines, putting just a space between them.
 284    Delete everything contained in parentheses.
 285    When a recipient name contains <...>, we discard
 286    everything except what is inside the <...>.
 287
 288    We don't pay attention to overflowing WHERE;
 289    the caller has to make it big enough.  */
 290
 291 char *
 292 add_field (line_list the_list, register char *field, register char *where)
 293 {
 294   register char c;
 295   while (true)
 296     {
 297       char *this_recipient_where;
 298       int in_quotes = 0;
 299
 300       *where++ = ' ';
 301       this_recipient_where = where;
 302
 303       while ((c = *field++) != '\0')
 304         {
 305           if (c == '\\')
 306             *where++ = c;
 307           else if (c == '"')
 308             {
 309               in_quotes = ! in_quotes;
 310               *where++ = c;
 311             }
 312           else if (in_quotes)
 313             *where++ = c;
 314           else if (c == '(')
 315             {
 316               while (*field && *field != ')') ++field;
 317               if (! (*field++)) break; /* no close */
 318               continue;
 319             }
 320           else if (c == ',')
 321             {
 322               *where++ = ' ';
 323               /* When we get to the end of one recipient,
 324                  don't discard it if the next one has <...>.  */
 325               this_recipient_where = where;
 326             }
 327           else if (c == '<')
 328             /* Discard everything we got before the `<'.  */
 329             where = this_recipient_where;
 330           else if (c == '>')
 331             /* Discard the rest of this name that follows the `>'.  */
 332             {
 333               while (*field && *field != ',') ++field;
 334               if (! (*field++)) break; /* no comma */
 335               continue;
 336             }
 337           else
 338             *where++ = c;
 339         }
 340       if (the_list == NIL) break;
 341       field = the_list->string;
 342       the_list = the_list->continuation;
 343     }
 344   return where;
 345 }
 346 \f
 347 line_list
 348 make_file_preface (void)
 349 {
 350   char *the_string, *temp;
 351   long idiotic_interface;
 352   struct tm *tm;
 353   long prefix_length;
 354   long user_length;
 355   long date_length;
 356   line_list result;
 357
 358   prefix_length = strlen (FROM_PREFIX);
 359   time (&idiotic_interface);
 360   /* Convert to a string, checking for out-of-range time stamps.
 361      Don't use 'ctime', as that might dump core if the hardware clock
 362      is set to a bizarre value.  */
 363   tm = localtime (&idiotic_interface);
 364   if (! (tm && TM_YEAR_IN_ASCTIME_RANGE (tm->tm_year)
 365          && (the_date = asctime (tm))))
 366     fatal ("current time is out of range");
 367   /* the_date has an unwanted newline at the end */
 368   date_length = strlen (the_date) - 1;
 369   the_date[date_length] = '\0';
 370   temp = cuserid ((char *) NULL);
 371   user_length = strlen (temp);
 372   the_user = alloc_string (user_length + 1);
 373   strcpy (the_user, temp);
 374   the_string = alloc_string (3 + prefix_length
 375                              + user_length
 376                              + date_length);
 377   temp = the_string;
 378   strcpy (temp, FROM_PREFIX);
 379   temp = &temp[prefix_length];
 380   *temp++ = ' ';
 381   strcpy (temp, the_user);
 382   temp = &temp[user_length];
 383   *temp++ = ' ';
 384   strcpy (temp, the_date);
 385   result = new_list ();
 386   result->string = the_string;
 387   result->continuation = ((line_list) NULL);
 388   return result;
 389 }
 390
 391 void
 392 write_line_list (register line_list the_list, FILE *the_stream)
 393 {
 394   for ( ;
 395       the_list != ((line_list) NULL) ;
 396       the_list = the_list->continuation)
 397     {
 398       fputs (the_list->string, the_stream);
 399       putc ('\n', the_stream);
 400     }
 401   return;
 402 }
 403 \f
 404 int
 405 close_the_streams (void)
 406 {
 407   register stream_list rem;
 408   for (rem = the_streams;
 409        rem != ((stream_list) NULL);
 410        rem = rem->rest_streams)
 411     no_problems = (no_problems &&
 412                    ((*rem->action) (rem->handle) == 0));
 413   the_streams = ((stream_list) NULL);
 414   return (no_problems ? EXIT_SUCCESS : EXIT_FAILURE);
 415 }
 416
 417 void
 418 add_a_stream (FILE *the_stream, int (*closing_action) (FILE *))
 419 {
 420   stream_list old = the_streams;
 421   the_streams = new_stream ();
 422   the_streams->handle = the_stream;
 423   the_streams->action = closing_action;
 424   the_streams->rest_streams = old;
 425   return;
 426 }
 427
 428 int
 429 my_fclose (FILE *the_file)
 430 {
 431   putc ('\n', the_file);
 432   fflush (the_file);
 433   return fclose (the_file);
 434 }
 435
 436 boolean
 437 open_a_file (char *name)
 438 {
 439   FILE *the_stream = fopen (name, "a");
 440   if (the_stream != ((FILE *) NULL))
 441     {
 442       add_a_stream (the_stream, my_fclose);
 443       if (the_user == ((char *) NULL))
 444         file_preface = make_file_preface ();
 445       write_line_list (file_preface, the_stream);
 446       return true;
 447     }
 448   return false;
 449 }
 450
 451 void
 452 put_string (char *s)
 453 {
 454   register stream_list rem;
 455   for (rem = the_streams;
 456        rem != ((stream_list) NULL);
 457        rem = rem->rest_streams)
 458     fputs (s, rem->handle);
 459   return;
 460 }
 461
 462 void
 463 put_line (const char *string)
 464 {
 465   register stream_list rem;
 466   for (rem = the_streams;
 467        rem != ((stream_list) NULL);
 468        rem = rem->rest_streams)
 469     {
 470       const char *s = string;
 471       int column = 0;
 472
 473       /* Divide STRING into lines.  */
 474       while (*s != 0)
 475         {
 476           const char *breakpos;
 477
 478           /* Find the last char that fits.  */
 479           for (breakpos = s; *breakpos && column < 78; ++breakpos)
 480             {
 481               if (*breakpos == '\t')
 482                 column += 8;
 483               else
 484                 column++;
 485             }
 486           /* If we didn't reach end of line, break the line.  */
 487           if (*breakpos)
 488             {
 489               /* Back up to just after the last comma that fits.  */
 490               while (breakpos != s && breakpos[-1] != ',') --breakpos;
 491
 492               if (breakpos == s)
 493                 {
 494                   /* If no comma fits, move past the first address anyway.  */
 495                   while (*breakpos != 0 && *breakpos != ',') ++breakpos;
 496                   if (*breakpos != 0)
 497                     /* Include the comma after it.  */
 498                     ++breakpos;
 499                 }
 500             }
 501           /* Output that much, then break the line.  */
 502           fwrite (s, 1, breakpos - s, rem->handle);
 503           column = 8;
 504
 505           /* Skip whitespace and prepare to print more addresses.  */
 506           s = breakpos;
 507           while (*s == ' ' || *s == '\t') ++s;
 508           if (*s != 0)
 509             fputs ("\n\t", rem->handle);
 510         }
 511       putc ('\n', rem->handle);
 512     }
 513   return;
 514 }
 515 \f
 516 #define mail_error error
 517
 518 /* Handle an FCC field.  FIELD is the text of the first line (after
 519    the header name), and THE_LIST holds the continuation lines if any.
 520    Call open_a_file for each file.  */
 521
 522 void
 523 setup_files (register line_list the_list, register char *field)
 524 {
 525   register char *start;
 526   register char c;
 527   while (true)
 528     {
 529       while (((c = *field) != '\0')
 530              && (c == ' '
 531                  || c == '\t'
 532                  || c == ','))
 533         field += 1;
 534       if (c != '\0')
 535         {
 536           start = field;
 537           while (((c = *field) != '\0')
 538                  && c != ' '
 539                  && c != '\t'
 540                  && c != ',')
 541             field += 1;
 542           *field = '\0';
 543           if (!open_a_file (start))
 544             mail_error ("Could not open file %s", start);
 545           *field = c;
 546           if (c != '\0') continue;
 547         }
 548       if (the_list == ((line_list) NULL))
 549         return;
 550       field = the_list->string;
 551       the_list = the_list->continuation;
 552     }
 553 }
 554 \f
 555 /* Compute the total size of all recipient names stored in THE_HEADER.
 556    The result says how big to make the buffer to pass to parse_header.  */
 557
 558 int
 559 args_size (header the_header)
 560 {
 561   register header old = the_header;
 562   register line_list rem;
 563   register int size = 0;
 564   do
 565     {
 566       char *field;
 567       register char *keyword = get_keyword (the_header->text->string, &field);
 568       if ((strcmp (keyword, "TO") == 0)
 569           || (strcmp (keyword, "CC") == 0)
 570           || (strcmp (keyword, "BCC") == 0))
 571         {
 572           size += 1 + strlen (field);
 573           for (rem = the_header->text->continuation;
 574                rem != NIL;
 575                rem = rem->continuation)
 576             size += 1 + strlen (rem->string);
 577         }
 578       the_header = the_header->next;
 579     } while (the_header != old);
 580   return size;
 581 }
 582
 583 /* Scan the header described by the lists THE_HEADER,
 584    and put all recipient names into the buffer WHERE.
 585    Precede each recipient name with a space.
 586
 587    Also, if the header has any FCC fields, call setup_files for each one.  */
 588
 589 void
 590 parse_header (header the_header, register char *where)
 591 {
 592   register header old = the_header;
 593   do
 594     {
 595       char *field;
 596       register char *keyword = get_keyword (the_header->text->string, &field);
 597       if (strcmp (keyword, "TO") == 0)
 598         where = add_field (the_header->text->continuation, field, where);
 599       else if (strcmp (keyword, "CC") == 0)
 600         where = add_field (the_header->text->continuation, field, where);
 601       else if (strcmp (keyword, "BCC") == 0)
 602         {
 603           where = add_field (the_header->text->continuation, field, where);
 604           the_header->previous->next = the_header->next;
 605           the_header->next->previous = the_header->previous;
 606         }
 607       else if (strcmp (keyword, "FCC") == 0)
 608         setup_files (the_header->text->continuation, field);
 609       the_header = the_header->next;
 610     } while (the_header != old);
 611   *where = '\0';
 612   return;
 613 }
 614 \f
 615 /* Read lines from the input until we get a blank line.
 616    Create a list of `header' objects, one for each header field,
 617    each of which points to a list of `line_list' objects,
 618    one for each line in that field.
 619    Continuation lines are grouped in the headers they continue.  */
 620
 621 header
 622 read_header (void)
 623 {
 624   register header the_header = ((header) NULL);
 625   register line_list *next_line = ((line_list *) NULL);
 626
 627   init_linebuffer (&lb);
 628
 629   do
 630     {
 631       long length;
 632       register char *line;
 633
 634       readline (&lb, stdin);
 635       line = lb.buffer;
 636       length = strlen (line);
 637       if (length == 0) break;
 638
 639       if (has_keyword (line))
 640         {
 641           register header old = the_header;
 642           the_header = new_header ();
 643           if (old == ((header) NULL))
 644             {
 645               the_header->next = the_header;
 646               the_header->previous = the_header;
 647             }
 648           else
 649             {
 650               the_header->previous = old;
 651               the_header->next = old->next;
 652               old->next = the_header;
 653             }
 654           next_line = &(the_header->text);
 655         }
 656
 657       if (next_line == ((line_list *) NULL))
 658         {
 659           /* Not a valid header */
 660           exit (EXIT_FAILURE);
 661         }
 662       *next_line = new_list ();
 663       (*next_line)->string = alloc_string (length);
 664       strcpy (((*next_line)->string), line);
 665       next_line = &((*next_line)->continuation);
 666       *next_line = NIL;
 667
 668     } while (true);
 669
 670   if (! the_header)
 671     fatal ("input message has no header");
 672   return the_header->next;
 673 }
 674 \f
 675 void
 676 write_header (header the_header)
 677 {
 678   register header old = the_header;
 679   do
 680     {
 681       register line_list the_list;
 682       for (the_list = the_header->text;
 683            the_list != NIL;
 684            the_list = the_list->continuation)
 685         put_line (the_list->string);
 686       the_header = the_header->next;
 687     } while (the_header != old);
 688   put_line ("");
 689   return;
 690 }
 691 \f
 692 int
 693 main (int argc, char **argv)
 694 {
 695   char *command_line;
 696   header the_header;
 697   long name_length;
 698   const char *mail_program_name;
 699   char buf[BUFLEN + 1];
 700   register int size;
 701   FILE *the_pipe;
 702
 703   mail_program_name = getenv ("FAKEMAILER");
 704   if (!(mail_program_name && *mail_program_name))
 705     mail_program_name = MAIL_PROGRAM_NAME;
 706   name_length = strlen (mail_program_name);
 707
 708   my_name = MY_NAME;
 709   the_streams = ((stream_list) NULL);
 710   the_date = ((char *) NULL);
 711   the_user = ((char *) NULL);
 712
 713   the_header = read_header ();
 714   command_line = alloc_string (name_length + args_size (the_header));
 715   strcpy (command_line, mail_program_name);
 716   parse_header (the_header, &command_line[name_length]);
 717
 718   the_pipe = popen (command_line, "w");
 719   if (the_pipe == ((FILE *) NULL))
 720     fatal ("cannot open pipe to real mailer");
 721
 722   add_a_stream (the_pipe, pclose);
 723
 724   write_header (the_header);
 725
 726   /* Dump the message itself */
 727
 728   while (!feof (stdin))
 729     {
 730       size = fread (buf, 1, BUFLEN, stdin);
 731       buf[size] = '\0';
 732       put_string (buf);
 733     }
 734
 735   exit (close_the_streams ());
 736 }
 737
 738 #endif /* not MSDOS */
 739 #endif /* not BSD 4.2 (or newer) */
 740
 741 /* arch-tag: acb0afa6-315a-4c5b-b9e3-def5725c8783
 742    (do not change this comment) */
 743
 744 /* fakemail.c ends here */