webcit/html2html.c

   1 /*
   2  * $Id$
   3  */
   4 /**
   5  * \defgroup HTML2HTML Output an HTML message, modifying it slightly to make sure it plays nice
   6  * with the rest of our web framework.
   7  *
   8  */
   9 /*@{*/
  10 #include "webcit.h"
  11 #include "vcard.h"
  12 #include "webserver.h"
  13
  14
  15 /**
  16  * \brief Sanitize and enhance an HTML message for display.
  17  * Also convert weird character sets to UTF-8 if necessary.
  18  * \param charset the input charset
  19  */
  20 void output_html(char *charset) {
  21         char buf[SIZ];
  22         char *msg;
  23         char *ptr;
  24         char *msgstart;
  25         char *msgend;
  26         char *converted_msg;
  27         int buffer_length = 1;
  28         int line_length = 0;
  29         int content_length = 0;
  30         int output_length = 0;
  31         char new_window[SIZ];
  32         int brak = 0;
  33         int alevel = 0;
  34         int i;
  35         int linklen;
  36 #ifdef HAVE_ICONV
  37         iconv_t ic = (iconv_t)(-1) ;
  38         char *ibuf;                   /**< Buffer of characters to be converted */
  39         char *obuf;                   /**< Buffer for converted characters      */
  40         size_t ibuflen;               /**< Length of input buffer               */
  41         size_t obuflen;               /**< Length of output buffer              */
  42         char *osav;                   /**< Saved pointer to output buffer       */
  43 #endif
  44
  45         msg = strdup("");
  46         sprintf(new_window, "<a target=\"%s\" href=", TARGET);
  47
  48         while (serv_getln(buf, sizeof buf), strcmp(buf, "000")) {
  49                 line_length = strlen(buf);
  50                 buffer_length = content_length + line_length + 2;
  51                 msg = realloc(msg, buffer_length);
  52                 if (msg == NULL) {
  53                         wprintf("<b>");
  54                         wprintf(_("realloc() error! couldn't get %d bytes: %s"),
  55                                 buffer_length + 1,
  56                                 strerror(errno));
  57                         wprintf("</b><br /><br />\n");
  58                         return;
  59                 }
  60                 strcpy(&msg[content_length], buf);
  61                 content_length += line_length;
  62                 strcpy(&msg[content_length], "\n");
  63                 content_length += 1;
  64         }
  65
  66 #ifdef HAVE_ICONV
  67         if ( (strcasecmp(charset, "us-ascii"))
  68            && (strcasecmp(charset, "UTF-8"))
  69            && (strcasecmp(charset, ""))
  70         ) {
  71                 ic = iconv_open("UTF-8", charset);
  72                 if (ic == (iconv_t)(-1) ) {
  73                         lprintf(5, "%s:%d iconv_open() failed: %s\n",
  74                                 __FILE__, __LINE__, strerror(errno));
  75                 }
  76         }
  77         if (ic != (iconv_t)(-1) ) {
  78                 ibuf = msg;
  79                 ibuflen = content_length;
  80                 obuflen = content_length + (content_length / 2) ;
  81                 obuf = (char *) malloc(obuflen);
  82                 osav = obuf;
  83                 iconv(ic, &ibuf, &ibuflen, &obuf, &obuflen);
  84                 content_length = content_length + (content_length / 2) - obuflen;
  85                 osav[content_length] = 0;
  86                 free(msg);
  87                 msg = osav;
  88                 iconv_close(ic);
  89         }
  90 #endif
  91
  92         ptr = msg;
  93         msgstart = msg;
  94         msgend = &msg[content_length];
  95
  96         while (ptr < msgend) {
  97
  98                 /** Advance to next tag */
  99                 ptr = strchr(ptr, '<');
 100                 if ((ptr == NULL) || (ptr >= msgend)) break;
 101                 ++ptr;
 102                 if ((ptr == NULL) || (ptr >= msgend)) break;
 103
 104                 /**
 105                  * Any of these tags cause everything up to and including
 106                  * the tag to be removed.
 107                  */
 108                 if ( (!strncasecmp(ptr, "HTML", 4))
 109                    ||(!strncasecmp(ptr, "HEAD", 4))
 110                    ||(!strncasecmp(ptr, "/HEAD", 5))
 111                    ||(!strncasecmp(ptr, "BODY", 4)) ) {
 112                         ptr = strchr(ptr, '>');
 113                         if ((ptr == NULL) || (ptr >= msgend)) break;
 114                         ++ptr;
 115                         if ((ptr == NULL) || (ptr >= msgend)) break;
 116                         msgstart = ptr;
 117                 }
 118
 119                 /**
 120                  * Any of these tags cause everything including and following
 121                  * the tag to be removed.
 122                  */
 123                 if ( (!strncasecmp(ptr, "/HTML", 5))
 124                    ||(!strncasecmp(ptr, "/BODY", 5)) ) {
 125                         --ptr;
 126                         msgend = ptr;
 127                         strcpy(ptr, "");
 128
 129                 }
 130
 131                 ++ptr;
 132         }
 133
 134         converted_msg = malloc(content_length);
 135         strcpy(converted_msg, "");
 136         ptr = msgstart;
 137         while (ptr < msgend) {
 138                 /**
 139                  * Change mailto: links to WebCit mail, by replacing the
 140                  * link with one that points back to our mail room.  Due to
 141                  * the way we parse URL's, it'll even handle mailto: links
 142                  * that have "?subject=" in them.
 143                  */
 144                 if (!strncasecmp(ptr, "<a href=\"mailto:", 16)) {
 145                         content_length += 64;
 146                         converted_msg = realloc(converted_msg, content_length);
 147                         sprintf(&converted_msg[output_length],
 148                                 "<a href=\"display_enter"
 149                                 "?force_room=_MAIL_&recp=");
 150                         output_length += 47;
 151                         ptr = &ptr[16];
 152                         ++alevel;
 153                 }
 154                 /** Make links open in a separate window */
 155                 else if (!strncasecmp(ptr, "<a href=", 8)) {
 156                         content_length += 64;
 157                         converted_msg = realloc(converted_msg, content_length);
 158                         sprintf(&converted_msg[output_length], new_window);
 159                         output_length += strlen(new_window);
 160                         ptr = &ptr[8];
 161                         ++alevel;
 162                 }
 163                 /**
 164                  * Turn anything that looks like a URL into a real link, as long
 165                  * as it's not inside a tag already
 166                  */
 167                 else if ( (brak == 0) && (alevel == 0)
 168                      && (!strncasecmp(ptr, "http://", 7))) {
 169                                 linklen = 0;
 170                                 /** Find the end of the link */
 171                                 for (i=0; i<=strlen(ptr); ++i) {
 172                                         if ((ptr[i]==0)
 173                                            ||(isspace(ptr[i]))
 174                                            ||(ptr[i]==10)
 175                                            ||(ptr[i]==13)
 176                                            ||(ptr[i]=='(')
 177                                            ||(ptr[i]==')')
 178                                            ||(ptr[i]=='<')
 179                                            ||(ptr[i]=='>')
 180                                            ||(ptr[i]=='[')
 181                                            ||(ptr[i]==']')
 182                                         ) linklen = i;
 183                                         if (linklen > 0) break;
 184                                 }
 185                                 if (linklen > 0) {
 186                                         content_length += (32 + linklen);
 187                                         converted_msg = realloc(converted_msg, content_length);
 188                                         sprintf(&converted_msg[output_length], new_window);
 189                                         output_length += strlen(new_window);
 190                                         converted_msg[output_length] = '\"';
 191                                         converted_msg[++output_length] = 0;
 192                                         for (i=0; i<linklen; ++i) {
 193                                                 converted_msg[output_length] = ptr[i];
 194                                                 converted_msg[++output_length] = 0;
 195                                         }
 196                                         sprintf(&converted_msg[output_length], "\">");
 197                                         output_length += 2;
 198                                         for (i=0; i<linklen; ++i) {
 199                                                 converted_msg[output_length] = *ptr++;
 200                                                 converted_msg[++output_length] = 0;
 201                                         }
 202                                         sprintf(&converted_msg[output_length], "</A>");
 203                                         output_length += 4;
 204                                 }
 205                 }
 206                 else {
 207                         /**
 208                          * We need to know when we're inside a tag,
 209                          * so we don't turn things that look like URL's into
 210                          * links, when they're already links - or image sources.
 211                          */
 212                         if (*ptr == '<') ++brak;
 213                         if (*ptr == '>') --brak;
 214                         if (!strncasecmp(ptr, "</A>", 3)) --alevel;
 215                         converted_msg[output_length] = *ptr++;
 216                         converted_msg[++output_length] = 0;
 217                 }
 218         }
 219
 220         /** Output our big pile of markup */
 221         client_write(converted_msg, output_length);
 222
 223         /** A little trailing vertical whitespace... */
 224         wprintf("<br /><br />\n");
 225
 226         /** Now give back the memory */
 227         free(converted_msg);
 228         free(msg);
 229 }
 230
 231 /*@}*/