citadel/mime_parser.c

   1 /*
   2  * mime_parser.c
   3  *
   4  * This is a really bad attempt at writing a parser to handle MIME-encoded
   5  * messages.
   6  *
   7  * Copyright (c) 1998-1999 by Art Cancro
   8  * This code is distributed under the terms of the GNU General Public License.
   9  *
  10  */
  11
  12 #include <stdlib.h>
  13 #include <unistd.h>
  14 #include <stdio.h>
  15 #include <signal.h>
  16 #include <sys/types.h>
  17 #include <ctype.h>
  18 #include <string.h>
  19 #include "mime_parser.h"
  20
  21
  22
  23 void extract_key(char *target, char *source, char *key) {
  24         int a, b;
  25
  26         strcpy(target, source);
  27         for (a=0; a<strlen(target); ++a) {
  28                 if ((!strncasecmp(&target[a], key, strlen(key)))
  29                    && (target[a+strlen(key)]=='=')) {
  30                         strcpy(target, &target[a+strlen(key)+1]);
  31                         if (target[0]==34) strcpy(target, &target[1]);
  32                         for (b=0; b<strlen(target); ++b)
  33                                 if (target[b]==34) target[b]=0;
  34                         return;
  35                         }
  36                 }
  37         strcpy(target, "");
  38         }
  39
  40
  41
  42         /**** OTHERWISE, HERE'S WHERE WE HANDLE THE STUFF!! *****
  43
  44         CallBack(name, filename, "", content, content_type, length);
  45
  46         **** END OF STUFF-HANDLER ****/
  47
  48
  49 /*
  50  * Utility function to "readline" from memory
  51  * (returns new pointer)
  52  */
  53 char *memreadline(char *start, char *buf, int maxlen) {
  54         char ch;
  55         char *ptr;
  56
  57         ptr = start;
  58         bzero(buf, maxlen);
  59
  60         while(1) {
  61                 ch = *ptr++;
  62                 if ((ch==10)||(ch==0)) {
  63                         if (strlen(buf)>0)
  64                                 if (buf[strlen(buf)-1]==13)
  65                                         buf[strlen(buf)-1] = 0;
  66                         return ptr;
  67                         }
  68                 if (strlen(buf) < (maxlen-1)) {
  69                         buf[strlen(buf)+1] = 0;
  70                         buf[strlen(buf)] = ch;
  71                         }
  72                 }
  73         }
  74
  75
  76
  77 /*
  78  * Break out the components of a multipart message
  79  * (This function expects to be fed HEADERS + CONTENT)
  80  */
  81 void mime_parser(char *content,
  82                 void (*CallBack)
  83                         (char *cbname,
  84                         char *cbfilename,
  85                         char *cbencoding,
  86                         void *cbcontent,
  87                         char *cbtype,
  88                         size_t cblength)
  89                 ) {
  90
  91         char *ptr;
  92         char *part_start, *part_end;
  93         char buf[256];
  94         char header[256];
  95         char boundary[256];
  96         char content_type[256];
  97         char encoding[256];
  98         int content_length;
  99         int i;
 100
 101         ptr = content;
 102         bzero(boundary, sizeof boundary);
 103         bzero(content_type, sizeof content_type);
 104         bzero(encoding, sizeof encoding);
 105         content_length = 0;
 106
 107         /* Learn interesting things from the headers */
 108         strcpy(header, "");
 109         do {
 110                 ptr = memreadline(ptr, buf, sizeof buf);
 111                 for (i=0; i<strlen(buf); ++i)
 112                         if (isspace(buf[i])) buf[i]=' ';
 113                 if (!isspace(buf[0])) {
 114                         if (!strncasecmp(header, "Content-type: ", 14))
 115                                 strcpy(content_type, &header[14]);
 116                         if (!strncasecmp(header, "Content-length: ", 16))
 117                                 content_length = atoi(&header[16]);
 118                         if (!strncasecmp(header,
 119                                 "Content-transfer-encoding: ", 27))
 120                                         strcpy(encoding, &header[27]);
 121                         if (strlen(boundary)==0)
 122                                 extract_key(boundary, header, "boundary");
 123                         strcpy(header, "");
 124                         }
 125                 if ((strlen(header)+strlen(buf)+2)<sizeof(header))
 126                         strcat(header, buf);
 127                 } while ((strlen(buf) > 0) && (*ptr != 0));
 128
 129         cprintf("Content type is <%s>\n", content_type);
 130         cprintf("Encoding is <%s>\n", encoding);
 131         cprintf("Content length is %d\n", content_length);
 132         cprintf("Boundary is <%s>\n", boundary);
 133
 134         if (*ptr == 0) return; /* premature end of message */
 135
 136         /* If this is a multipart message, then recursively process it */
 137         if (strlen(boundary)>0) {
 138                 }
 139
 140
 141         }