webcit-ng/server/forum_view.c

   1 // The code in here feeds messages out as JSON to the client browser.  It is currently being used
   2 // for the forum view, but as we implement other views we'll probably reuse a lot of what's here.
   3 //
   4 // Copyright (c) 1996-2022 by the citadel.org team
   5 //
   6 // This program is open source software.  Use, duplication, or
   7 // disclosure are subject to the GNU General Public License v3.
   8
   9 #include "webcit.h"
  10
  11 // Commands we need to send to Citadel Server before we begin rendering forum view.
  12 // These are common to flat and threaded views.
  13 void setup_for_forum_view(struct ctdlsession *c) {
  14         char buf[1024];
  15         ctdl_printf(c, "MSGP text/html|text/plain");    // Declare the MIME types we know how to render
  16         ctdl_readline(c, buf, sizeof(buf));             // Ignore the response
  17         ctdl_printf(c, "MSGP dont_decode");             // Tell the server we will decode base64/etc client-side
  18         ctdl_readline(c, buf, sizeof(buf));             // Ignore the response
  19 }
  20
  21
  22 // Fetch a single message and return it in JSON format for client-side rendering
  23 void json_render_one_message(struct http_transaction *h, struct ctdlsession *c, long msgnum) {
  24         StrBuf *raw_msg = NULL;
  25         StrBuf *sanitized_msg = NULL;
  26         char buf[1024];
  27         char content_transfer_encoding[1024] = { 0 };
  28         char content_type[1024] = { 0 };
  29         char datetime[128] = { 0 };
  30         int message_originated_locally = 0;
  31
  32         setup_for_forum_view(c);
  33
  34         ctdl_printf(c, "MSG4 %ld", msgnum);
  35         ctdl_readline(c, buf, sizeof(buf));
  36         if (buf[0] != '1') {
  37                 do_404(h);
  38                 return;
  39         }
  40
  41         JsonValue *j = NewJsonObject(HKEY("message"));
  42         JsonObjectAppend(j, NewJsonNumber(HKEY("msgnum"), msgnum));
  43
  44         while ((ctdl_readline(c, buf, sizeof(buf)) >= 0) && (strcmp(buf, "text")) && (strcmp(buf, "000"))) {
  45                 utf8ify_rfc822_string(&buf[5]);
  46
  47                 // citadel header parsing here
  48                 if (!strncasecmp(buf, "from=", 5)) {
  49                         JsonObjectAppend(j, NewJsonPlainString(HKEY("from"), &buf[5], -1));
  50                 }
  51                 else if (!strncasecmp(buf, "rfca=", 5)) {
  52                         JsonObjectAppend(j, NewJsonPlainString(HKEY("rfca"), &buf[5], -1));
  53                 }
  54                 else if (!strncasecmp(buf, "time=", 5)) {
  55                         JsonObjectAppend(j, NewJsonNumber(HKEY("time"), atol(&buf[5])));
  56                 }
  57                 else if (!strncasecmp(buf, "locl=", 5)) {
  58                         message_originated_locally = 1;
  59                 }
  60                 else if (!strncasecmp(buf, "subj=", 5)) {
  61                         JsonObjectAppend(j, NewJsonPlainString(HKEY("subj"), &buf[5], -1));
  62                 }
  63                 else if (!strncasecmp(buf, "msgn=", 5)) {
  64                         JsonObjectAppend(j, NewJsonPlainString(HKEY("msgn"), &buf[5], -1));
  65                 }
  66                 else if (!strncasecmp(buf, "wefw=", 5)) {
  67                         JsonObjectAppend(j, NewJsonPlainString(HKEY("wefw"), &buf[5], -1));
  68                 }
  69         }
  70
  71         JsonObjectAppend(j, NewJsonNumber(HKEY("locl"), message_originated_locally));
  72
  73         if (!strcmp(buf, "text")) {
  74                 while ((ctdl_readline(c, buf, sizeof(buf)) >= 0) && (strcmp(buf, "")) && (strcmp(buf, "000"))) {
  75                         // rfc822 header parsing here
  76                         if (!strncasecmp(buf, "Content-transfer-encoding:", 26)) {
  77                                 strcpy(content_transfer_encoding, &buf[26]);
  78                                 striplt(content_transfer_encoding);
  79                         }
  80                         if (!strncasecmp(buf, "Content-type:", 13)) {
  81                                 strcpy(content_type, &buf[13]);
  82                                 striplt(content_type);
  83                         }
  84                 }
  85                 if (!strcmp(buf, "000")) {              // if we have an empty message, don't try to read further
  86                         raw_msg = NULL;
  87                 }
  88                 else {
  89                         raw_msg = ctdl_readtextmsg(c);
  90                 }
  91         }
  92         else {
  93                 raw_msg = NULL;
  94         }
  95
  96         if (raw_msg) {
  97                 // These are the encodings we know how to handle.  Decode in-place.
  98
  99                 if (!strcasecmp(content_transfer_encoding, "base64")) {
 100                         StrBufDecodeBase64(raw_msg);
 101                 }
 102                 if (!strcasecmp(content_transfer_encoding, "quoted-printable")) {
 103                         StrBufDecodeQP(raw_msg);
 104                 }
 105
 106                 // At this point, raw_msg contains the decoded message.
 107                 // Now run through the renderers we have available.
 108
 109                 if (!strncasecmp(content_type, "text/html", 9)) {
 110                         sanitized_msg = html2html("UTF-8", 0, c->room, msgnum, raw_msg);
 111                 }
 112                 else if (!strncasecmp(content_type, "text/plain", 10)) {
 113                         sanitized_msg = text2html("UTF-8", 0, c->room, msgnum, raw_msg);
 114                 }
 115                 else if (!strncasecmp(content_type, "text/x-citadel-variformat", 25)) {
 116                         sanitized_msg = variformat2html(raw_msg);
 117                 }
 118                 else {
 119                         sanitized_msg = NewStrBufPlain(HKEY("<i>No renderer for this content type</i><br>"));
 120                         syslog(LOG_WARNING, "forum_view: no renderer for content type %s", content_type);
 121                 }
 122                 FreeStrBuf(&raw_msg);
 123
 124                 // If sanitized_msg is not NULL, we have rendered the message and can output it.
 125                 if (sanitized_msg) {
 126                         JsonObjectAppend(j, NewJsonString(HKEY("text"), sanitized_msg, NEWJSONSTRING_SMASHBUF));
 127                 }
 128                 else {
 129                         syslog(LOG_WARNING, "forum_view: message %ld of content type %s converted to NULL", msgnum, content_type);
 130                 }
 131         }
 132
 133         StrBuf *sj = NewStrBuf();
 134         SerializeJson(sj, j, 1);        // '1' == free the source object
 135
 136         add_response_header(h, strdup("Content-type"), strdup("application/json"));
 137         h->response_code = 200;
 138         h->response_string = strdup("OK");
 139         h->response_body_length = StrLength(sj);
 140         h->response_body = SmashStrBuf(&sj);
 141 }