Mon Mar 19 11:30:27 2012

Asterisk developer's documentation


func_dialgroup.c

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Copyright (C) 2007, Tilghman Lesher
00005  *
00006  * Tilghman Lesher <func_dialgroup__200709@the-tilghman.com>
00007  *
00008  * See http://www.asterisk.org for more information about
00009  * the Asterisk project. Please do not directly contact
00010  * any of the maintainers of this project for assistance;
00011  * the project provides a web site, mailing lists and IRC
00012  * channels for your use.
00013  *
00014  * This program is free software, distributed under the terms of
00015  * the GNU General Public License Version 2. See the LICENSE file
00016  * at the top of the source tree.
00017  */
00018 
00019 /*! \file
00020  *
00021  * \brief Dial group dialplan function
00022  *
00023  * \author Tilghman Lesher <func_dialgroup__200709@the-tilghman.com>
00024  *
00025  * \ingroup functions
00026  */
00027 
00028 /*** MODULEINFO
00029    <support_level>core</support_level>
00030  ***/
00031 
00032 #include "asterisk.h"
00033 
00034 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 343336 $")
00035 
00036 #include <sys/stat.h>
00037 
00038 #include "asterisk/module.h"
00039 #include "asterisk/channel.h"
00040 #include "asterisk/pbx.h"
00041 #include "asterisk/utils.h"
00042 #include "asterisk/app.h"
00043 #include "asterisk/astobj2.h"
00044 #include "asterisk/astdb.h"
00045 
00046 /*** DOCUMENTATION
00047    <function name="DIALGROUP" language="en_US">
00048       <synopsis>
00049          Manages a group of users for dialing.
00050       </synopsis>
00051       <syntax>
00052          <parameter name="group" required="true" />
00053          <parameter name="op">
00054             <para>The operation name, possible values are:</para>
00055             <para><literal>add</literal> - add a channel name or interface (write-only)</para>
00056             <para><literal>del</literal> - remove a channel name or interface (write-only)</para>
00057          </parameter>
00058       </syntax>
00059       <description>
00060          <para>Presents an interface meant to be used in concert with the Dial
00061          application, by presenting a list of channels which should be dialled when
00062          referenced.</para>
00063          <para>When DIALGROUP is read from, the argument is interpreted as the particular
00064          <replaceable>group</replaceable> for which a dial should be attempted.  When DIALGROUP is written to
00065          with no arguments, the entire list is replaced with the argument specified.</para>
00066          <para>Functionality is similar to a queue, except that when no interfaces are
00067          available, execution may continue in the dialplan.  This is useful when
00068          you want certain people to be the first to answer any calls, with immediate
00069          fallback to a queue when the front line people are busy or unavailable, but
00070          you still want front line people to log in and out of that group, just like
00071          a queue.</para>
00072          <para>Example:</para>
00073          <para>exten => 1,1,Set(DIALGROUP(mygroup,add)=SIP/10)</para>
00074          <para>exten => 1,n,Set(DIALGROUP(mygroup,add)=SIP/20)</para>
00075          <para>exten => 1,n,Dial(${DIALGROUP(mygroup)})</para>
00076       </description>
00077    </function>
00078  ***/
00079 
00080 static struct ao2_container *group_container = NULL;
00081 
00082 struct group_entry {
00083    char name[AST_CHANNEL_NAME];
00084 };
00085 
00086 struct group {
00087    char name[AST_MAX_EXTENSION];
00088    struct ao2_container *entries;
00089 };
00090 
00091 static void group_destroy(void *vgroup)
00092 {
00093    struct group *group = vgroup;
00094    ao2_ref(group->entries, -1);
00095 }
00096 
00097 static int group_hash_fn(const void *obj, const int flags)
00098 {
00099    const struct group *g = obj;
00100    return ast_str_hash(g->name);
00101 }
00102 
00103 static int group_cmp_fn(void *obj1, void *name2, int flags)
00104 {
00105    struct group *g1 = obj1, *g2 = name2;
00106    char *name = name2;
00107    if (flags & OBJ_POINTER)
00108       return strcmp(g1->name, g2->name) ? 0 : CMP_MATCH | CMP_STOP;
00109    else
00110       return strcmp(g1->name, name) ? 0 : CMP_MATCH | CMP_STOP;
00111 }
00112 
00113 static int entry_hash_fn(const void *obj, const int flags)
00114 {
00115    const struct group_entry *e = obj;
00116    return ast_str_hash(e->name);
00117 }
00118 
00119 static int entry_cmp_fn(void *obj1, void *name2, int flags)
00120 {
00121    struct group_entry *e1 = obj1, *e2 = name2;
00122    char *name = name2;
00123    if (flags & OBJ_POINTER)
00124       return strcmp(e1->name, e2->name) ? 0 : CMP_MATCH | CMP_STOP;
00125    else
00126       return strcmp(e1->name, name) ? 0 : CMP_MATCH | CMP_STOP;
00127 }
00128 
00129 static int dialgroup_read(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
00130 {
00131    struct ao2_iterator i;
00132    struct group *grhead = ao2_find(group_container, data, 0);
00133    struct group_entry *entry;
00134    size_t bufused = 0;
00135    int trunc_warning = 0;
00136    int res = 0;
00137 
00138    if (!grhead) {
00139       if (!ast_strlen_zero(cmd)) {
00140          ast_log(LOG_WARNING, "No such dialgroup '%s'\n", data);
00141       }
00142       return -1;
00143    }
00144 
00145    buf[0] = '\0';
00146 
00147    i = ao2_iterator_init(grhead->entries, 0);
00148    while ((entry = ao2_iterator_next(&i))) {
00149       int tmp = strlen(entry->name);
00150       /* Ensure that we copy only complete names, not partials */
00151       if (len - bufused > tmp + 2) {
00152          if (bufused != 0)
00153             buf[bufused++] = '&';
00154          ast_copy_string(buf + bufused, entry->name, len - bufused);
00155          bufused += tmp;
00156       } else if (trunc_warning++ == 0) {
00157          if (!ast_strlen_zero(cmd)) {
00158             ast_log(LOG_WARNING, "Dialgroup '%s' is too large.  Truncating list.\n", data);
00159          } else {
00160             res = 1;
00161             ao2_ref(entry, -1);
00162             break;
00163          }
00164       }
00165       ao2_ref(entry, -1);
00166    }
00167    ao2_iterator_destroy(&i);
00168 
00169    return res;
00170 }
00171 
00172 static int dialgroup_refreshdb(struct ast_channel *chan, const char *cdialgroup)
00173 {
00174    int len = 500, res = 0;
00175    char *buf = NULL;
00176    char *dialgroup = ast_strdupa(cdialgroup);
00177 
00178    do {
00179       len *= 2;
00180       buf = ast_realloc(buf, len);
00181 
00182       if ((res = dialgroup_read(chan, "", dialgroup, buf, len)) < 0) {
00183          ast_free(buf);
00184          return -1;
00185       }
00186    } while (res == 1);
00187 
00188    if (ast_strlen_zero(buf)) {
00189       ast_db_del("dialgroup", cdialgroup);
00190    } else {
00191       ast_db_put("dialgroup", cdialgroup, buf);
00192    }
00193    ast_free(buf);
00194    return 0;
00195 }
00196 
00197 static int dialgroup_write(struct ast_channel *chan, const char *cmd, char *data, const char *cvalue)
00198 {
00199    struct group *grhead;
00200    struct group_entry *entry;
00201    int j, needrefresh = 1;
00202    AST_DECLARE_APP_ARGS(args,
00203       AST_APP_ARG(group);
00204       AST_APP_ARG(op);
00205    );
00206    AST_DECLARE_APP_ARGS(inter,
00207       AST_APP_ARG(faces)[100];
00208    );
00209    char *value = ast_strdupa(cvalue);
00210 
00211    AST_STANDARD_APP_ARGS(args, data);
00212    AST_NONSTANDARD_APP_ARGS(inter, value, '&');
00213 
00214    if (!(grhead = ao2_find(group_container, args.group, 0))) {
00215       /* Create group */
00216       grhead = ao2_alloc(sizeof(*grhead), group_destroy);
00217       if (!grhead)
00218          return -1;
00219       grhead->entries = ao2_container_alloc(37, entry_hash_fn, entry_cmp_fn);
00220       if (!grhead->entries) {
00221          ao2_ref(grhead, -1);
00222          return -1;
00223       }
00224       ast_copy_string(grhead->name, args.group, sizeof(grhead->name));
00225       ao2_link(group_container, grhead);
00226    }
00227 
00228    if (ast_strlen_zero(args.op)) {
00229       /* Wholesale replacement of the group */
00230       args.op = "add";
00231 
00232       /* Remove all existing */
00233       ao2_ref(grhead->entries, -1);
00234       if (!(grhead->entries = ao2_container_alloc(37, entry_hash_fn, entry_cmp_fn))) {
00235          ao2_unlink(group_container, grhead);
00236          ao2_ref(grhead, -1);
00237          return -1;
00238       }
00239    }
00240 
00241    if (strcasecmp(args.op, "add") == 0) {
00242       for (j = 0; j < inter.argc; j++) {
00243          /* Eliminate duplicates */
00244          if ((entry = ao2_find(grhead->entries, inter.faces[j], 0))) {
00245             ao2_ref(entry, -1);
00246             continue;
00247          }
00248          if ((entry = ao2_alloc(sizeof(*entry), NULL))) {
00249             ast_copy_string(entry->name, inter.faces[j], sizeof(entry->name));
00250             ao2_link(grhead->entries, entry);
00251             ao2_ref(entry, -1);
00252          } else {
00253             ast_log(LOG_WARNING, "Unable to add '%s' to dialgroup '%s'\n", inter.faces[j], grhead->name);
00254          }
00255       }
00256    } else if (strncasecmp(args.op, "del", 3) == 0) {
00257       for (j = 0; j < inter.argc; j++) {
00258          if ((entry = ao2_find(grhead->entries, inter.faces[j], OBJ_UNLINK))) {
00259             ao2_ref(entry, -1);
00260          } else {
00261             ast_log(LOG_WARNING, "Interface '%s' not found in dialgroup '%s'\n", inter.faces[j], grhead->name);
00262          }
00263       }
00264    } else {
00265       ast_log(LOG_ERROR, "Unrecognized operation: %s\n", args.op);
00266       needrefresh = 0;
00267    }
00268    ao2_ref(grhead, -1);
00269 
00270    if (needrefresh) {
00271       dialgroup_refreshdb(chan, args.group);
00272    }
00273 
00274    return 0;
00275 }
00276 
00277 static struct ast_custom_function dialgroup_function = {
00278    .name = "DIALGROUP",
00279    .read = dialgroup_read,
00280    .write = dialgroup_write,
00281 };
00282 
00283 static int unload_module(void)
00284 {
00285    int res = ast_custom_function_unregister(&dialgroup_function);
00286    ao2_ref(group_container, -1);
00287    return res;
00288 }
00289 
00290 static int load_module(void)
00291 {
00292    struct ast_db_entry *dbtree, *tmp;
00293    char groupname[AST_MAX_EXTENSION], *ptr;
00294 
00295    if ((group_container = ao2_container_alloc(37, group_hash_fn, group_cmp_fn))) {
00296       /* Refresh groups from astdb */
00297       if ((dbtree = ast_db_gettree("dialgroup", NULL))) {
00298          for (tmp = dbtree; tmp; tmp = tmp->next) {
00299             ast_copy_string(groupname, tmp->key, sizeof(groupname));
00300             if ((ptr = strrchr(groupname, '/'))) {
00301                ptr++;
00302                dialgroup_write(NULL, "", ptr, tmp->data);
00303             }
00304          }
00305          ast_db_freetree(dbtree);
00306       }
00307       return ast_custom_function_register(&dialgroup_function);
00308    } else {
00309       return AST_MODULE_LOAD_DECLINE;
00310    }
00311 }
00312 
00313 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Dialgroup dialplan function");

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