libpurple/protocols/bonjour/mdns_common.c

   1 /*
   2  *  This program is free software; you can redistribute it and/or modify
   3  *  it under the terms of the GNU General Public License as published by
   4  *  the Free Software Foundation; either version 2 of the License, or
   5  *  (at your option) any later version.
   6  *
   7  *  This program is distributed in the hope that it will be useful,
   8  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  *  GNU Library General Public License for more details.
  11  *
  12  *  You should have received a copy of the GNU General Public License
  13  *  along with this program; if not, write to the Free Software
  14  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1301, USA.
  15  */
  16
  17 #include <string.h>
  18
  19 #include "internal.h"
  20 #include "debug.h"
  21
  22 #include "mdns_common.h"
  23 #include "mdns_interface.h"
  24 #include "bonjour.h"
  25 #include "buddy.h"
  26
  27
  28 /**
  29  * Allocate space for the dns-sd data.
  30  */
  31 BonjourDnsSd * bonjour_dns_sd_new() {
  32         BonjourDnsSd *data = g_new0(BonjourDnsSd, 1);
  33         return data;
  34 }
  35
  36 /**
  37  * Deallocate the space of the dns-sd data.
  38  */
  39 void bonjour_dns_sd_free(BonjourDnsSd *data) {
  40         g_free(data->first);
  41         g_free(data->last);
  42         g_free(data->phsh);
  43         g_free(data->status);
  44         g_free(data->vc);
  45         g_free(data->msg);
  46         g_free(data);
  47 }
  48
  49 #define MAX_TXT_CONSTITUENT_LEN 255
  50
  51 /* Make sure that the value isn't longer than it is supposed to be */
  52 static const char*
  53 get_max_txt_record_value(const char *key, const char *value)
  54 {
  55         /* "each constituent string of a DNS TXT record is limited to 255 bytes"
  56          * This includes the key and the '='
  57          */
  58         static char buffer[MAX_TXT_CONSTITUENT_LEN + 1];
  59         gchar *end_valid = NULL;
  60         int len = MIN(strlen(value), MAX_TXT_CONSTITUENT_LEN - (strlen(key) + 2));
  61
  62         strncpy(buffer, value, len);
  63
  64         buffer[len] = '\0';
  65
  66         /* If we've cut part of a utf-8 character, kill it */
  67         if (!g_utf8_validate(buffer, -1, (const gchar **)&end_valid))
  68                 *end_valid = '\0';
  69
  70         return buffer;
  71 }
  72
  73 static GSList *generate_presence_txt_records(BonjourDnsSd *data) {
  74         GSList *ret = NULL;
  75         PurpleKeyValuePair *kvp;
  76         char portstring[6];
  77         const char *jid, *aim, *email;
  78
  79         /* Convert the port to a string */
  80         snprintf(portstring, sizeof(portstring), "%d", data->port_p2pj);
  81
  82         jid = purple_account_get_string(data->account, "jid", NULL);
  83         aim = purple_account_get_string(data->account, "AIM", NULL);
  84         email = purple_account_get_string(data->account, "email", NULL);
  85
  86 #define _M_ADD_R(k, v) \
  87         kvp = g_new0(PurpleKeyValuePair, 1); \
  88         kvp->key = g_strdup(k); \
  89         kvp->value = g_strdup(get_max_txt_record_value(k, v)); \
  90         ret = g_slist_prepend(ret, kvp); \
  91
  92         /* We should try to follow XEP-0174, but some clients have "issues", so we humor them.
  93          * See http://telepathy.freedesktop.org/wiki/SalutInteroperability
  94          */
  95
  96         /* Large TXT records are problematic.
  97          * While it is technically possible for this to exceed a standard 512-byte
  98          * DNS message, it shouldn't happen unless we get wacky data entered for
  99          * some of the freeform fields.  It is even less likely to exceed the
 100          * recommended maximum of 1300 bytes.
 101          */
 102
 103         /* Needed by iChat */
 104         _M_ADD_R("txtvers", "1")
 105         /* Needed by Gaim/Pidgin <= 2.0.1 (remove at some point) */
 106         _M_ADD_R("1st", data->first)
 107         /* Needed by Gaim/Pidgin <= 2.0.1 (remove at some point) */
 108         _M_ADD_R("last", data->last)
 109         /* Needed by Adium */
 110         _M_ADD_R("port.p2pj", portstring)
 111         /* Needed by iChat, Gaim/Pidgin <= 2.0.1 */
 112         _M_ADD_R("status", data->status)
 113         _M_ADD_R("node", "libpurple")
 114         _M_ADD_R("ver", VERSION)
 115         /* Currently always set to "!" since we don't support AV and wont ever be in a conference */
 116         _M_ADD_R("vc", data->vc)
 117         if (email != NULL && *email != '\0') {
 118                 _M_ADD_R("email", email)
 119         }
 120         if (jid != NULL && *jid != '\0') {
 121                 _M_ADD_R("jid", jid)
 122         }
 123         /* Nonstandard, but used by iChat */
 124         if (aim != NULL && *aim != '\0') {
 125                 _M_ADD_R("AIM", aim)
 126         }
 127         if (data->msg != NULL && *data->msg != '\0') {
 128                 _M_ADD_R("msg", data->msg)
 129         }
 130         if (data->phsh != NULL && *data->phsh != '\0') {
 131                 _M_ADD_R("phsh", data->phsh)
 132         }
 133
 134         /* TODO: ext, nick */
 135         return ret;
 136 }
 137
 138 static void free_presence_txt_records(GSList *lst) {
 139         PurpleKeyValuePair *kvp;
 140         while(lst) {
 141                 kvp = lst->data;
 142                 g_free(kvp->key);
 143                 g_free(kvp->value);
 144                 g_free(kvp);
 145                 lst = g_slist_remove(lst, lst->data);
 146         }
 147 }
 148
 149 static gboolean publish_presence(BonjourDnsSd *data, PublishType type) {
 150         GSList *txt_records;
 151         gboolean ret;
 152
 153         txt_records = generate_presence_txt_records(data);
 154         ret = _mdns_publish(data, type, txt_records);
 155         free_presence_txt_records(txt_records);
 156
 157         return ret;
 158 }
 159
 160 /**
 161  * Send a new dns-sd packet updating our status.
 162  */
 163 void bonjour_dns_sd_send_status(BonjourDnsSd *data, const char *status, const char *status_message) {
 164         g_free(data->status);
 165         g_free(data->msg);
 166
 167         data->status = g_strdup(status);
 168         data->msg = g_strdup(status_message);
 169
 170         /* Update our text record with the new status */
 171         publish_presence(data, PUBLISH_UPDATE);
 172 }
 173
 174 /**
 175  * Retrieve the buddy icon blob
 176  */
 177 void bonjour_dns_sd_retrieve_buddy_icon(BonjourBuddy* buddy) {
 178         _mdns_retrieve_buddy_icon(buddy);
 179 }
 180
 181 void bonjour_dns_sd_update_buddy_icon(BonjourDnsSd *data) {
 182         PurpleStoredImage *img;
 183
 184         if ((img = purple_buddy_icons_find_account_icon(data->account))) {
 185                 gconstpointer avatar_data;
 186                 gsize avatar_len;
 187
 188                 avatar_data = purple_imgstore_get_data(img);
 189                 avatar_len = purple_imgstore_get_size(img);
 190
 191                 if (_mdns_set_buddy_icon_data(data, avatar_data, avatar_len)) {
 192                         /* The filename is a SHA-1 hash of the data (conveniently what we need) */
 193                         const char *p, *filename = purple_imgstore_get_filename(img);
 194
 195                         g_free(data->phsh);
 196                         data->phsh = NULL;
 197
 198                         /* Get rid of the extension */
 199                         p = strchr(filename, '.');
 200                         if (p)
 201                                 data->phsh = g_strndup(filename, p - filename);
 202                         else
 203                                 purple_debug_error("bonjour", "account buddy icon returned unexpected filename (%s)"
 204                                                                 "; unable to extract hash. Clearing buddy icon\n", filename);
 205
 206                         /* Update our TXT record */
 207                         publish_presence(data, PUBLISH_UPDATE);
 208                 }
 209
 210                 purple_imgstore_unref(img);
 211         } else {
 212                 /* We need to do this regardless of whether data->phsh is set so that we
 213                  * cancel any icons that are currently in the process of being set */
 214                 _mdns_set_buddy_icon_data(data, NULL, 0);
 215                 if (data->phsh != NULL) {
 216                         /* Clear the buddy icon */
 217                         g_free(data->phsh);
 218                         data->phsh = NULL;
 219                         /* Update our TXT record */
 220                         publish_presence(data, PUBLISH_UPDATE);
 221                 }
 222         }
 223 }
 224
 225 /**
 226  * Advertise our presence within the dns-sd daemon and start browsing
 227  * for other bonjour peers.
 228  */
 229 gboolean bonjour_dns_sd_start(BonjourDnsSd *data) {
 230
 231         /* Initialize the dns-sd data and session */
 232         if (!_mdns_init_session(data))
 233                 return FALSE;
 234
 235         /* Publish our bonjour IM client at the mDNS daemon */
 236         if (!publish_presence(data, PUBLISH_START))
 237                 return FALSE;
 238
 239         /* Advise the daemon that we are waiting for connections */
 240         if (!_mdns_browse(data)) {
 241                 purple_debug_error("bonjour", "Unable to get service.\n");
 242                 return FALSE;
 243         }
 244
 245         return TRUE;
 246 }
 247
 248 /**
 249  * Unregister the "_presence._tcp" service at the mDNS daemon.
 250  */
 251
 252 void bonjour_dns_sd_stop(BonjourDnsSd *data) {
 253         _mdns_stop(data);
 254 }