jabberd2  2.2.16
sx/ack.c
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00001 /*
00002  * jabberd - Jabber Open Source Server
00003  * Copyright (c) 2007 Tomasz Sterna
00004  *
00005  * This program is free software; you can redistribute it and/or modify
00006  * it under the terms of the GNU General Public License as published by
00007  * the Free Software Foundation; version 2 of the License
00008  *
00009  * This program is distributed in the hope that it will be useful,
00010  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00011  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
00012  * GNU General Public License for more details.
00013  *
00014  * You should have received a copy of the GNU General Public License
00015  * along with this program; if not, write to the Free Software
00016  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA02111-1307USA
00017  */
00018 
00019 /*
00020  * this sx plugin implements stanza acknowledgements
00021  * as described in XEP-0198: Stanza Acknowledgements
00022  */
00023 
00024 #include "sx.h"
00025 
00026 #define STREAM_ACK_NS_DECL      " xmlns:ack='" uri_ACK "'"
00027 
00028 static void _sx_ack_header(sx_t s, sx_plugin_t p, sx_buf_t buf) {
00029 
00030     log_debug(ZONE, "hacking ack namespace decl onto stream header");
00031 
00032     /* get enough space */
00033     _sx_buffer_alloc_margin(buf, 0, strlen(STREAM_ACK_NS_DECL) + 2);
00034 
00035     /* overwrite the trailing ">" with a decl followed by a new ">" */
00036     memcpy(&buf->data[buf->len - 1], STREAM_ACK_NS_DECL ">", strlen(STREAM_ACK_NS_DECL)+1);
00037     buf->len += strlen(STREAM_ACK_NS_DECL);
00038 }
00039 
00041 static void _sx_ack_features(sx_t s, sx_plugin_t p, nad_t nad) {
00042     /* offer feature only when authenticated and not enabled yet */
00043     if(s->state == state_OPEN && s->plugin_data[p->index] == NULL)
00044         nad_append_elem(nad, -1, "ack:ack", 1);
00045 }
00046 
00048 static int _sx_ack_process(sx_t s, sx_plugin_t p, nad_t nad) {
00049     int attr;
00050 
00051     /* not interested if we're not a server */
00052     if(s->type != type_SERVER)
00053         return 1;
00054 
00055     /* only want ack packets */
00056     if((NAD_ENS(nad, 0) < 0 || NAD_NURI_L(nad, NAD_ENS(nad, 0)) != strlen(uri_ACK) || strncmp(NAD_NURI(nad, NAD_ENS(nad, 0)), uri_ACK, strlen(uri_ACK)) != 0))
00057         return 1;
00058 
00059     /* pings */
00060     if(NAD_ENAME_L(nad, 0) == 4 && strncmp(NAD_ENAME(nad, 0), "ping", 4) == 0) {
00061         jqueue_push(s->wbufq, _sx_buffer_new("<ack:pong/>", 11, NULL, NULL), 0);
00062         s->want_write = 1;
00063 
00064         /* handled the packet */
00065         nad_free(nad);
00066         return 0;
00067     }
00068 
00069     /* enable only when authenticated */
00070     if(s->state == state_OPEN && NAD_ENAME_L(nad, 0) == 6 && strncmp(NAD_ENAME(nad, 0), "enable", 6) == 0) {
00071         jqueue_push(s->wbufq, _sx_buffer_new("<ack:enabled/>", 14, NULL, NULL), 254);
00072         s->want_write = 1;
00073 
00074         s->plugin_data[p->index] = (void *) 1;
00075 
00076         /* handled the packet */
00077         nad_free(nad);
00078         return 0;
00079     }
00080 
00081     /* 'r' or 'a' when enabled */
00082     if(s->plugin_data[p->index] != NULL && NAD_ENAME_L(nad, 0) == 1 && (strncmp(NAD_ENAME(nad, 0), "r", 1) == 0 || strncmp(NAD_ENAME(nad, 0), "a", 1) == 0) ) {
00083         attr = nad_find_attr(nad, 0, -1, "c", NULL);
00084         if(attr >= 0) {
00085             char *buf = (char *) malloc(sizeof(char) * (NAD_AVAL_L(nad, attr) + 13 + 1));
00086             snprintf(buf, NAD_AVAL_L(nad, attr) + 13 + 1, "<ack:a b='%.*s'/>", NAD_AVAL_L(nad, attr), NAD_AVAL(nad, attr));
00087             jqueue_push(s->wbufq, _sx_buffer_new(buf, NAD_AVAL_L(nad, attr) + 13, NULL, NULL), 255);
00088             free(buf);
00089             s->want_write = 1;
00090         }
00091         
00092         /* handled the packet */
00093         nad_free(nad);
00094         return 0;
00095     }
00096 
00097     _sx_debug(ZONE, "unhandled ack namespace element '%.*s', dropping packet", NAD_ENAME_L(nad, 0), NAD_ENAME(nad, 0));
00098     nad_free(nad);
00099     return 0;
00100 }
00101 
00103 int sx_ack_init(sx_env_t env, sx_plugin_t p, va_list args) {
00104     log_debug(ZONE, "initialising stanza acknowledgements sx plugin");
00105 
00106     p->header = _sx_ack_header;
00107     p->features = _sx_ack_features;
00108     p->process = _sx_ack_process;
00109 
00110     return 0;
00111 }