XEP-0363: HTTP File Upload

Add initial support for XEP-0363. HTTP uploads can be used when colon
separated values for stdin is enabled:

~~~

u::::<filename>|<size (bytes)>[|<content-type>]

u::::example.png%7C16698

u::::tr.png%7C16698%7Cimage%2Fpng
~~~

The reponse:

~~~
U:upload.example.com:user@example.com/477937350262208314215778:https%3A%2F%2Fexample.com%2Fupload%2F1234%2Fabc%2Fexample.png%7Chttps%3A%2F%2Fexample.com%2Fupload%2F1234%2Fabc%2Fexample.png
~~~

TODO:

* support PUT header elements
* support/test error conditions

Questions:

* save the maximum file size returned by the server and disallow uploads
  larger than the value?

* xmppipe is "pinned" to the upload server returned in the IQ reply (the
  "to" field is ignored)

  * allow other upload servers?
  * error if different upload server is specified in "u:<from>:<to>"?

src/iq.c

@@ -0,0 +1,91 @@
+/* Copyright (c) 2019, Michael Santos <michael.santos@gmail.com>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+#include "xmppipe.h"
+
+int handle_iq(xmpp_conn_t *const conn, xmpp_stanza_t *const stanza,
+              void *const userdata) {
+  xmppipe_state_t *state = userdata;
+  xmpp_stanza_t *slot;
+  xmpp_stanza_t *item;
+
+  const char *from = NULL;
+  const char *to = NULL;
+  const char *get = NULL;
+  const char *put = NULL;
+
+  char *efrom;
+  char *eto;
+  char *eget;
+  char *eput;
+
+  from = xmpp_stanza_get_attribute(stanza, "from");
+
+  if (from == NULL)
+    return 1;
+
+  slot = xmpp_stanza_get_child_by_ns(stanza, "urn:xmpp:http:upload:0");
+
+  /* only handles XEP 0363 */
+  if (slot == NULL)
+    return 1;
+
+  to = xmpp_stanza_get_attribute(stanza, "to");
+
+  if (to == NULL)
+    return 1;
+
+  if (XMPPIPE_STRNEQ(from, state->upload)) {
+    if (state->verbose)
+      (void)fprintf(stderr,
+                    "error: received XEP363 slot from: %s (using: %s)\n", from,
+                    state->upload);
+    return 1;
+  }
+
+  for (item = xmpp_stanza_get_children(slot); item != NULL;
+       item = xmpp_stanza_get_next(item)) {
+    const char *name = xmpp_stanza_get_name(item);
+
+    if (name == NULL)
+      continue;
+
+    if (XMPPIPE_STREQ(name, "get"))
+      get = xmpp_stanza_get_attribute(item, "url");
+
+    if (XMPPIPE_STREQ(name, "put"))
+      put = xmpp_stanza_get_attribute(item, "url");
+  }
+
+  if (get == NULL || put == NULL)
+    return 1;
+
+  efrom = xmppipe_fmt_encode(from);
+  eto = xmppipe_fmt_encode(to);
+
+  eget = xmppipe_fmt_encode(get);
+  eput = xmppipe_fmt_encode(put);
+
+  (void)printf("U:%s:%s:%s:%s%%7c%s\n",
+               state->opt & XMPPIPE_OPT_GROUPCHAT ? "groupchat" : "chat", efrom,
+               eto, eget, eput);
+
+  free(efrom);
+  free(eto);
+
+  free(eget);
+  free(eput);
+
+  return 1;
+}

src/xmppipe.c

@@ -327,6 +327,7 @@ int xmppipe_stream_init(xmppipe_state_t *state) {
   xmpp_handler_add(state->conn, handle_message, NULL, "message", NULL, state);
   xmpp_handler_add(state->conn, handle_version, "jabber:iq:version", "iq", NULL,
                    state);
+  xmpp_handler_add(state->conn, handle_iq, NULL, "iq", "result", state);
   xmpp_id_handler_add(state->conn, handle_ping_reply, "c2s1", state);
 
   /* XXX multiple handlers can be called for each event
@@ -521,6 +522,11 @@ int handle_disco_info(xmpp_conn_t *const conn, xmpp_stanza_t *const stanza,
     if (var == NULL)
       continue;
 
+    if (XMPPIPE_STREQ(var, "urn:xmpp:http:upload:0")) {
+      state->upload = xmppipe_strdup(from);
+      continue;
+    }
+
     if (XMPPIPE_STRNEQ(var, "http://jabber.org/protocol/muc"))
       continue;
 
@@ -533,7 +539,7 @@ int handle_disco_info(xmpp_conn_t *const conn, xmpp_stanza_t *const stanza,
       xmppipe_muc_unlock(state);
     }
 
-    return 0;
+    return 1;
   }
 
   return 1;
@@ -563,7 +569,8 @@ static void usage(xmppipe_state_t *state) {
       "   -S, --subject <subject>             set MUC subject\n"
       "   -a, --address <addr:port>           set XMPP server address (port is "
       "optional)\n"
-      "   -F, --format <text|csv>             stdin is text (default) or colon separated values\n"
+      "   -F, --format <text|csv>             stdin is text (default) or colon "
+      "separated values\n"
 
       "   -d, --discard                       discard stdin when MUC is empty\n"
       "   -D, --discard-to-stdout             discard stdin and print to local "

src/xmppipe.h

@@ -57,7 +57,7 @@ enum {
       1 << 1,                   /* Throw away stdin and send to local stdout */
   XMPPIPE_OPT_EOF = 1 << 2,     /* Keep running on stdin EOF */
   XMPPIPE_OPT_SIGPIPE = 1 << 3, /* Exit if no occupants in MUC */
-  XMPPIPE_OPT_GROUPCHAT = 1 << 4,   /* Use groupchat */
+  XMPPIPE_OPT_GROUPCHAT = 1 << 4, /* Use groupchat */
 };
 
 enum { XMPPIPE_FMT_TEXT = 0, XMPPIPE_FMT_CSV };
@@ -75,6 +75,8 @@ typedef struct {
   char *subject;    /* topic/subject for MUC */
   char *out;        /* room@conference.xmpp.example.com */
 
+  char *upload; /* XEP 0363 upload service */
+
   int status;
   int occupants;
   u_int32_t poll;      /* milliseconds */
@@ -118,6 +120,8 @@ int handle_sm_ack(xmpp_conn_t *const, xmpp_stanza_t *const, void *const);
 int handle_sm_enabled(xmpp_conn_t *const, xmpp_stanza_t *const, void *const);
 int handle_sm_request(xmpp_conn_t *const, xmpp_stanza_t *const, void *const);
 int handle_version(xmpp_conn_t *const, xmpp_stanza_t *const, void *const);
+int handle_iq(xmpp_conn_t *const conn, xmpp_stanza_t *const stanza,
+              void *const userdata);
 
 void xmppipe_muc_join(xmppipe_state_t *);
 void xmppipe_muc_subject(xmppipe_state_t *, char *);

src/xmppipe_send.c

@@ -17,6 +17,9 @@
 void xmppipe_send_oob(xmppipe_state_t *state, char *to, char *type, char *buf,
                       size_t len);
 
+void xmppipe_send_http_upload(xmppipe_state_t *state, char *to, char *type,
+                              char *buf, size_t len);
+
 void xmppipe_send_stanza(xmppipe_state_t *state, char *buf, size_t len) {
   switch (state->format) {
   case XMPPIPE_FMT_TEXT:
@@ -84,7 +87,8 @@ void xmppipe_send_stanza_fmt(xmppipe_state_t *state, char *buf, size_t len) {
 
       switch (start[0]) {
       case 'm': /* message */
-      case 'I': /* message: inline image using oob */
+      case 'I': /* message: iniline image using oob stanza */
+      case 'u': /* iq: http upload slot */
         break;
       case 'p':
       /* unsupported: fall through */
@@ -133,6 +137,9 @@ XMPPIPE_DONE:
     case 'I':
       xmppipe_send_oob(state, to, type, body, strlen(body));
       break;
+    case 'u':
+      xmppipe_send_http_upload(state, to, type, body, strlen(body));
+      break;
     case 'm':
     default:
       xmppipe_send_message(state, to, type, body, strlen(body));
@@ -217,6 +224,87 @@ void xmppipe_send_oob(xmppipe_state_t *state, char *to, char *type, char *buf,
   xmpp_free(state->ctx, id);
 }
 
+void xmppipe_send_http_upload(xmppipe_state_t *state, char *to, char *type,
+                              char *buf, size_t len) {
+  xmpp_stanza_t *iq;
+  xmpp_stanza_t *request;
+  char *id;
+  char *filename = NULL;
+  char *size = NULL;
+  char *content_type = NULL;
+
+  int i;
+  char *start;
+  char *end;
+
+  if (state->upload == NULL) {
+    if (state->verbose)
+      (void)fprintf(stderr, "error: XEP 0363 http upload is not supported\n");
+    return;
+  }
+
+  id = xmpp_uuid_gen(state->ctx);
+
+  if (id == NULL) {
+    errx(EXIT_FAILURE, "unable to allocate message id");
+  }
+
+  start = buf;
+
+  /* <filename>|<size>|<content-type> */
+  for (i = 0; start != NULL; i++) {
+    end = strchr(start, '|');
+    if (end != NULL)
+      *end++ = '\0';
+
+    switch (i) {
+    case 0: /* filename */
+      filename = start;
+      break;
+    case 1: /* size */
+      size = start;
+      break;
+    case 2: /* content-type */
+      content_type = start;
+      break;
+    default:
+      /* invalid */
+      break;
+    }
+
+    start = end;
+  }
+
+  if (filename == NULL || size == NULL) {
+    if (state->verbose)
+      (void)fprintf(stderr, "error: invalid http upload request\n");
+    return;
+  }
+
+  iq = xmppipe_stanza_new(state->ctx);
+  xmppipe_stanza_set_name(iq, "iq");
+  xmppipe_stanza_set_attribute(iq, "id", id);
+  xmppipe_stanza_set_attribute(iq, "type", "get");
+  xmppipe_stanza_set_attribute(iq, "to", state->upload);
+
+  request = xmppipe_stanza_new(state->ctx);
+  xmppipe_stanza_set_name(request, "request");
+  xmppipe_stanza_set_ns(request, "urn:xmpp:http:upload:0");
+  xmppipe_stanza_set_attribute(request, "filename", filename);
+  xmppipe_stanza_set_attribute(request, "size", size);
+
+  if (content_type)
+    xmppipe_stanza_set_attribute(request, "content-type", content_type);
+
+  xmppipe_stanza_add_child(iq, request);
+  (void)xmpp_stanza_release(request);
+
+  xmppipe_send(state, iq);
+
+  (void)xmpp_stanza_release(iq);
+  xmpp_free(state->ctx, id);
+}
+
 void xmppipe_send(xmppipe_state_t *state, xmpp_stanza_t *const stanza) {
   xmpp_stanza_t *r = NULL;