webcit-ng/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.  It runs great on the
   7 // Linux operating system (and probably elsewhere).  You can use,
   8 // copy, and run it under the terms of the GNU General Public
   9 // License version 3.
  10 //
  11 // This program is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 #include "webcit.h"
  17
  18 // Commands we need to send to Citadel Server before we begin rendering forum view.
  19 // These are common to flat and threaded views.
  20 void setup_for_forum_view(struct ctdlsession *c) {
  21         char buf[1024];
  22         ctdl_printf(c, "MSGP text/html|text/plain");    // Declare the MIME types we know how to render
  23         ctdl_readline(c, buf, sizeof(buf));             // Ignore the response
  24         ctdl_printf(c, "MSGP dont_decode");             // Tell the server we will decode base64/etc client-side
  25         ctdl_readline(c, buf, sizeof(buf));             // Ignore the response
  26 }
  27
  28
  29 // Fetch a single message and return it in JSON format for client-side rendering
  30 void json_render_one_message(struct http_transaction *h, struct ctdlsession *c, long msgnum) {
  31         StrBuf *raw_msg = NULL;
  32         StrBuf *sanitized_msg = NULL;
  33         char buf[1024];
  34         char content_transfer_encoding[1024] = { 0 };
  35         char content_type[1024] = { 0 };
  36         char datetime[128] = { 0 };
  37         char author[1024] = { 0 };
  38         char emailaddr[1024] = { 0 };
  39         int message_originated_locally = 0;
  40
  41         setup_for_forum_view(c);
  42
  43         ctdl_printf(c, "MSG4 %ld", msgnum);
  44         ctdl_readline(c, buf, sizeof(buf));
  45         if (buf[0] != '1') {
  46                 do_404(h);
  47                 return;
  48         }
  49
  50         JsonValue *j = NewJsonObject(HKEY("message"));
  51
  52         while ((ctdl_readline(c, buf, sizeof(buf)) >= 0) && (strcmp(buf, "text")) && (strcmp(buf, "000"))) {
  53
  54                 // citadel header parsing here
  55                 if (!strncasecmp(buf, "from=", 5)) {
  56                         safestrncpy(author, &buf[5], sizeof author);
  57                 }
  58                 else if (!strncasecmp(buf, "rfca=", 5)) {
  59                         safestrncpy(emailaddr, &buf[5], sizeof emailaddr);
  60                 }
  61                 else if (!strncasecmp(buf, "time=", 5)) {
  62                         JsonObjectAppend(j, NewJsonNumber(HKEY("time"), atol(&buf[5])));
  63                 }
  64                 else if (!strncasecmp(buf, "locl=", 5)) {
  65                         message_originated_locally = 1;
  66                 }
  67                 else if (!strncasecmp(buf, "subj=", 5)) {
  68                         JsonObjectAppend(j, NewJsonPlainString(HKEY("subj"), &buf[5], -1));
  69                 }
  70                 else if (!strncasecmp(buf, "msgn=", 5)) {
  71                         JsonObjectAppend(j, NewJsonPlainString(HKEY("msgn"), &buf[5], -1));
  72                 }
  73                 else if (!strncasecmp(buf, "wefw=", 5)) {
  74                         JsonObjectAppend(j, NewJsonPlainString(HKEY("wefw"), &buf[5], -1));
  75                 }
  76         }
  77
  78         if (message_originated_locally) {
  79                 JsonObjectAppend(j, NewJsonPlainString(HKEY("from"), author, -1));
  80         }
  81         else {
  82                 JsonObjectAppend(j, NewJsonPlainString(HKEY("from"), emailaddr, -1));           // FIXME do compound address string
  83         }
  84
  85         if (!strcmp(buf, "text")) {
  86                 while ((ctdl_readline(c, buf, sizeof(buf)) >= 0) && (strcmp(buf, "")) && (strcmp(buf, "000"))) {
  87                         // rfc822 header parsing here
  88                         if (!strncasecmp(buf, "Content-transfer-encoding:", 26)) {
  89                                 strcpy(content_transfer_encoding, &buf[26]);
  90                                 striplt(content_transfer_encoding);
  91                         }
  92                         if (!strncasecmp(buf, "Content-type:", 13)) {
  93                                 strcpy(content_type, &buf[13]);
  94                                 striplt(content_type);
  95                         }
  96                 }
  97                 if (!strcmp(buf, "000")) {              // if we have an empty message, don't try to read further
  98                         raw_msg = NULL;
  99                 }
 100                 else {
 101                         raw_msg = ctdl_readtextmsg(c);
 102                 }
 103         }
 104         else {
 105                 raw_msg = NULL;
 106         }
 107
 108         if (raw_msg) {
 109                 // These are the encodings we know how to handle.  Decode in-place.
 110
 111                 if (!strcasecmp(content_transfer_encoding, "base64")) {
 112                         StrBufDecodeBase64(raw_msg);
 113                 }
 114                 if (!strcasecmp(content_transfer_encoding, "quoted-printable")) {
 115                         StrBufDecodeQP(raw_msg);
 116                 }
 117
 118                 // At this point, raw_msg contains the decoded message.
 119                 // Now run through the renderers we have available.
 120
 121                 if (!strncasecmp(content_type, "text/html", 9)) {
 122                         sanitized_msg = html2html("UTF-8", 0, c->room, msgnum, raw_msg);
 123                 }
 124                 else if (!strncasecmp(content_type, "text/plain", 10)) {
 125                         sanitized_msg = text2html("UTF-8", 0, c->room, msgnum, raw_msg);
 126                 }
 127                 else if (!strncasecmp(content_type, "text/x-citadel-variformat", 25)) {
 128                         sanitized_msg = variformat2html(raw_msg);
 129                 }
 130                 else {
 131                         sanitized_msg = NewStrBufPlain(HKEY("<i>No renderer for this content type</i><br>"));
 132                         syslog(LOG_WARNING, "forum_view: no renderer for content type %s", content_type);
 133                 }
 134                 FreeStrBuf(&raw_msg);
 135
 136                 // If sanitized_msg is not NULL, we have rendered the message and can output it.
 137                 if (sanitized_msg) {
 138                         JsonObjectAppend(j, NewJsonString(HKEY("text"), sanitized_msg, NEWJSONSTRING_SMASHBUF));
 139                 }
 140                 else {
 141                         syslog(LOG_WARNING, "forum_view: message %ld of content type %s converted to NULL", msgnum, content_type);
 142                 }
 143         }
 144
 145         StrBuf *sj = NewStrBuf();
 146         SerializeJson(sj, j, 1);        // '1' == free the source object
 147
 148         add_response_header(h, strdup("Content-type"), strdup("application/json"));
 149         h->response_code = 200;
 150         h->response_string = strdup("OK");
 151         h->response_body_length = StrLength(sj);
 152         h->response_body = SmashStrBuf(&sj);
 153 }