file.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2006, Digium, Inc.
 *
 * Mark Spencer <markster@digium.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */
 
/*! \file
 *
 * \brief Generic File Format Support.
 *
 * \author Mark Spencer <markster@digium.com>
 */
 
/*** MODULEINFO
    <support_level>core</support_level>
 ***/
 
#include "asterisk.h"
 
#include <dirent.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <math.h>
 
#include "asterisk/_private.h"  /* declare ast_file_init() */
#include "asterisk/paths.h" /* use ast_config_AST_DATA_DIR */
#include "asterisk/mod_format.h"
#include "asterisk/cli.h"
#include "asterisk/channel.h"
#include "asterisk/sched.h"
#include "asterisk/translate.h"
#include "asterisk/utils.h"
#include "asterisk/lock.h"
#include "asterisk/app.h"
#include "asterisk/pbx.h"
#include "asterisk/linkedlists.h"
#include "asterisk/module.h"
#include "asterisk/astobj2.h"
#include "asterisk/test.h"
#include "asterisk/stasis.h"
#include "asterisk/json.h"
#include "asterisk/stasis_system.h"
#include "asterisk/media_cache.h"
 
/*! \brief
 * The following variable controls the layout of localized sound files.
 * If 0, use the historical layout with prefix just before the filename
 * (i.e. digits/en/1.gsm , digits/it/1.gsm or default to digits/1.gsm),
 * if 1 put the prefix at the beginning of the filename
 * (i.e. en/digits/1.gsm, it/digits/1.gsm or default to digits/1.gsm).
 * The latter permits a language to be entirely in one directory.
 *
 * This is settable in asterisk.conf.
 */
int ast_language_is_prefix = 1;
 
static AST_RWLIST_HEAD_STATIC(formats, ast_format_def);
 
STASIS_MESSAGE_TYPE_DEFN(ast_format_register_type);
STASIS_MESSAGE_TYPE_DEFN(ast_format_unregister_type);
 
static struct ast_json *json_array_from_list(const char *list, const char *sep)
{
    RAII_VAR(struct ast_json *, array, ast_json_array_create(), ast_json_unref);
    char *stringp, *ext;
 
    stringp = ast_strdupa(list);    /* this is in the stack so does not need to be freed */
    if (!array || !stringp) {
        return NULL;
    }
 
    while ((ext = strsep(&stringp, sep))) {
        if (ast_json_array_append(array, ast_json_string_create(ext))) {
            return NULL;
        }
    }
 
    return ast_json_ref(array);
}
 
static int publish_format_update(const struct ast_format_def *f, struct stasis_message_type *type)
{
    RAII_VAR(struct stasis_message *, msg, NULL, ao2_cleanup);
    RAII_VAR(struct ast_json_payload *, json_payload, NULL, ao2_cleanup);
    RAII_VAR(struct ast_json *, json_object, NULL, ast_json_unref);
 
    if (!type) {
        return -1;
    }
 
    json_object = ast_json_pack("{s: s, s: o}",
        "format", f->name,
        "extensions", json_array_from_list(f->exts, "|"));
    if (!json_object) {
        return -1;
    }
 
    json_payload = ast_json_payload_create(json_object);
    if (!json_payload) {
        return -1;
    }
 
    msg = stasis_message_create(type, json_payload);
    if (!msg) {
        return -1;
    }
 
    stasis_publish(ast_system_topic(), msg);
    return 0;
}
 
int __ast_format_def_register(const struct ast_format_def *f, struct ast_module *mod)
{
    struct ast_format_def *tmp;
 
    AST_RWLIST_WRLOCK(&formats);
    AST_RWLIST_TRAVERSE(&formats, tmp, list) {
        if (!strcasecmp(f->name, tmp->name)) {
            AST_RWLIST_UNLOCK(&formats);
            ast_log(LOG_WARNING, "Tried to register '%s' format, already registered\n", f->name);
            return -1;
        }
    }
    if (!(tmp = ast_calloc(1, sizeof(*tmp)))) {
        AST_RWLIST_UNLOCK(&formats);
        return -1;
    }
    *tmp = *f;
    tmp->module = mod;
    if (tmp->buf_size) {
        /*
         * Align buf_size properly, rounding up to the machine-specific
         * alignment for pointers.
         */
        struct _test_align { void *a, *b; } p;
        int align = (char *)&p.b - (char *)&p.a;
        tmp->buf_size = ((f->buf_size + align - 1) / align) * align;
    }
 
    memset(&tmp->list, 0, sizeof(tmp->list));
 
    AST_RWLIST_INSERT_HEAD(&formats, tmp, list);
    AST_RWLIST_UNLOCK(&formats);
    ast_verb(5, "Registered file format %s, extension(s) %s\n", f->name, f->exts);
    publish_format_update(f, ast_format_register_type());
 
    return 0;
}
 
int ast_format_def_unregister(const char *name)
{
    struct ast_format_def *tmp;
    int res = -1;
 
    AST_RWLIST_WRLOCK(&formats);
    AST_RWLIST_TRAVERSE_SAFE_BEGIN(&formats, tmp, list) {
        if (!strcasecmp(name, tmp->name)) {
            AST_RWLIST_REMOVE_CURRENT(list);
            publish_format_update(tmp, ast_format_unregister_type());
            ast_free(tmp);
            res = 0;
        }
    }
    AST_RWLIST_TRAVERSE_SAFE_END;
    AST_RWLIST_UNLOCK(&formats);
 
    if (!res)
        ast_verb(5, "Unregistered format %s\n", name);
    else
        ast_log(LOG_WARNING, "Tried to unregister format %s, already unregistered\n", name);
 
    return res;
}
 
FILE *ast_file_mkftemp(char *template_name, mode_t mode)
{
    FILE *p = NULL;
    int pfd = mkstemp(template_name);
    chmod(template_name, mode);
    if (pfd > -1) {
        p = fdopen(pfd, "w+");
        if (!p) {
            close(pfd);
            pfd = -1;
        }
    }
    return p;
}
 
int ast_file_fdtemp(const char *path, char **filename, const char *template_name)
{
    int fd;
 
    if (ast_asprintf(filename, "%s/%s", path, template_name) < 0) {
        ast_log(LOG_ERROR, "Failed to set up temporary file path\n");
        return -1;
    }
 
    ast_mkdir(path, 0644);
 
    if ((fd = mkstemp(*filename)) < 0) {
        ast_log(LOG_NOTICE, "Failed to create temporary file\n");
        ast_free(*filename);
        return -1;
    }
 
    return fd;
}
 
int ast_stopstream(struct ast_channel *tmp)
{
    ast_channel_lock(tmp);
 
    /* Stop a running stream if there is one */
    if (ast_channel_stream(tmp)) {
        ast_closestream(ast_channel_stream(tmp));
        ast_channel_stream_set(tmp, NULL);
        if (ast_channel_oldwriteformat(tmp) && ast_set_write_format(tmp, ast_channel_oldwriteformat(tmp)))
            ast_log(LOG_WARNING, "Unable to restore format back to %s\n", ast_format_get_name(ast_channel_oldwriteformat(tmp)));
    }
    /* Stop the video stream too */
    if (ast_channel_vstream(tmp) != NULL) {
        ast_closestream(ast_channel_vstream(tmp));
        ast_channel_vstream_set(tmp, NULL);
    }
 
    ast_channel_unlock(tmp);
 
    return 0;
}
 
int ast_writestream(struct ast_filestream *fs, struct ast_frame *f)
{
    int res = -1;
    if (f->frametype == AST_FRAME_VIDEO) {
        if (ast_format_get_type(fs->fmt->format) == AST_MEDIA_TYPE_AUDIO) {
            /* This is the audio portion.  Call the video one... */
            if (!fs->vfs && fs->filename) {
                const char *type = ast_format_get_name(f->subclass.format);
                fs->vfs = ast_writefile(fs->filename, type, NULL, fs->flags, 0, fs->mode);
                ast_debug(1, "Opened video output file\n");
            }
            if (fs->vfs)
                return ast_writestream(fs->vfs, f);
            /* else ignore */
            return 0;
        }
    } else if (f->frametype != AST_FRAME_VOICE) {
        ast_log(LOG_WARNING, "Tried to write non-voice frame\n");
        return -1;
    }
    if (ast_format_cmp(f->subclass.format, fs->fmt->format) != AST_FORMAT_CMP_NOT_EQUAL) {
        res =  fs->fmt->write(fs, f);
        if (res < 0)
            ast_log(LOG_WARNING, "Natural write failed\n");
        else if (res > 0)
            ast_log(LOG_WARNING, "Huh??\n");
    } else {
        /* XXX If they try to send us a type of frame that isn't the normal frame, and isn't
               the one we've setup a translator for, we do the "wrong thing" XXX */
        if (fs->trans && (ast_format_cmp(f->subclass.format, fs->lastwriteformat) != AST_FORMAT_CMP_EQUAL)) {
            ast_translator_free_path(fs->trans);
            fs->trans = NULL;
        }
        if (!fs->trans) {
            fs->trans = ast_translator_build_path(fs->fmt->format, f->subclass.format);
        }
        if (!fs->trans) {
            ast_log(LOG_WARNING, "Unable to translate to format %s, source format %s\n",
                fs->fmt->name, ast_format_get_name(f->subclass.format));
        } else {
            struct ast_frame *trf;
            ao2_replace(fs->lastwriteformat, f->subclass.format);
            /* Get the translated frame but don't consume the original in case they're using it on another stream */
            if ((trf = ast_translate(fs->trans, f, 0))) {
                struct ast_frame *cur;
 
                /* the translator may have returned multiple frames, so process them */
                for (cur = trf; cur; cur = AST_LIST_NEXT(cur, frame_list)) {
                    if ((res = fs->fmt->write(fs, trf))) {
                        ast_log(LOG_WARNING, "Translated frame write failed\n");
                        break;
                    }
                }
                ast_frfree(trf);
            } else {
                res = 0;
            }
        }
    }
    return res;
}
 
static int copy(const char *infile, const char *outfile)
{
    int ifd, ofd, len;
    char buf[4096]; /* XXX make it larger. */
 
    if ((ifd = open(infile, O_RDONLY)) < 0) {
        ast_log(LOG_WARNING, "Unable to open %s in read-only mode\n", infile);
        return -1;
    }
    if ((ofd = open(outfile, O_WRONLY | O_TRUNC | O_CREAT, AST_FILE_MODE)) < 0) {
        ast_log(LOG_WARNING, "Unable to open %s in write-only mode\n", outfile);
        close(ifd);
        return -1;
    }
    while ( (len = read(ifd, buf, sizeof(buf)) ) ) {
        int res;
        if (len < 0) {
            ast_log(LOG_WARNING, "Read failed on %s: %s\n", infile, strerror(errno));
            break;
        }
        /* XXX handle partial writes */
        res = write(ofd, buf, len);
        if (res != len) {
            ast_log(LOG_WARNING, "Write failed on %s (%d of %d): %s\n", outfile, res, len, strerror(errno));
            len = -1; /* error marker */
            break;
        }
    }
    close(ifd);
    close(ofd);
    if (len < 0) {
        unlink(outfile);
        return -1; /* error */
    }
    return 0;   /* success */
}
 
/*!
 * \brief construct a filename. Absolute pathnames are preserved,
 * relative names are prefixed by the sounds/ directory.
 * The wav49 suffix is replaced by 'WAV'.
 * Returns a malloc'ed string to be freed by the caller.
 */
static char *build_filename(const char *filename, const char *ext)
{
    char *fn = NULL;
 
    /* The wav49 -> WAV translation is duplicated in apps/app_mixmonitor.c, so
       if you change it here you need to change it there as well */
    if (!strcmp(ext, "wav49"))
        ext = "WAV";
 
    if (filename[0] == '/') {
        if (ast_asprintf(&fn, "%s.%s", filename, ext) < 0) {
            fn = NULL;
        }
    } else {
        if (ast_asprintf(&fn, "%s/sounds/%s.%s",
                 ast_config_AST_DATA_DIR, filename, ext) < 0) {
            fn = NULL;
        }
    }
    return fn;
}
 
/* compare type against the list 'exts' */
/* XXX need a better algorithm */
static int type_in_list(const char *list, const char *type, int (*cmp)(const char *s1, const char *s2))
{
    char *stringp = ast_strdupa(list), *item;
 
    while ((item = strsep(&stringp, "|"))) {
        if (!cmp(item, type)) {
            return 1;
        }
    }
 
    return 0;
}
 
#define exts_compare(list, type) (type_in_list((list), (type), strcmp))
 
/*!
 * \internal
 * \brief Close the file stream by canceling any pending read / write callbacks
 */
static void filestream_close(struct ast_filestream *f)
{
    enum ast_media_type format_type = ast_format_get_type(f->fmt->format);
 
    if (!f->owner) {
        return;
    }
 
    /* Stop a running stream if there is one */
    switch (format_type)
    {
    case AST_MEDIA_TYPE_AUDIO:
        ast_channel_stream_set(f->owner, NULL);
        AST_SCHED_DEL_ACCESSOR(ast_channel_sched(f->owner), f->owner, ast_channel_streamid, ast_channel_streamid_set);
        ast_settimeout(f->owner, 0, NULL, NULL);
        break;
    case AST_MEDIA_TYPE_VIDEO:
        ast_channel_vstream_set(f->owner, NULL);
        AST_SCHED_DEL_ACCESSOR(ast_channel_sched(f->owner), f->owner, ast_channel_vstreamid, ast_channel_vstreamid_set);
        break;
    default:
        ast_log(AST_LOG_WARNING, "Unable to schedule deletion of filestream with unsupported type %s\n", f->fmt->name);
        break;
    }
}
 
static void filestream_destructor(void *arg)
{
    struct ast_filestream *f = arg;
    int status;
    int pid = -1;
 
    /* Stop a running stream if there is one */
    filestream_close(f);
 
    /* destroy the translator on exit */
    if (f->trans)
        ast_translator_free_path(f->trans);
 
    if (f->fmt->close) {
        void (*closefn)(struct ast_filestream *) = f->fmt->close;
        closefn(f);
    }
 
    if (f->f) {
        fclose(f->f);
    }
 
    if (f->realfilename && f->filename) {
        pid = ast_safe_fork(0);
        if (!pid) {
            execl("/bin/mv", "mv", "-f", f->filename, f->realfilename, SENTINEL);
            _exit(1);
        }
        else if (pid > 0) {
            /* Block the parent until the move is complete.*/
            waitpid(pid, &status, 0);
        }
    }
 
    ast_free(f->filename);
    ast_free(f->realfilename);
    if (f->vfs)
        ast_closestream(f->vfs);
    ast_free(f->write_buffer);
    ast_free((void *)f->orig_chan_name);
    ao2_cleanup(f->lastwriteformat);
    ao2_cleanup(f->fr.subclass.format);
    ast_module_unref(f->fmt->module);
}
 
static struct ast_filestream *get_filestream(struct ast_format_def *fmt, FILE *bfile)
{
    struct ast_filestream *s;
    int l = sizeof(*s) + fmt->buf_size + fmt->desc_size;    /* total allocation size */
 
    if (!ast_module_running_ref(fmt->module)) {
        return NULL;
    }
 
    s = ao2_alloc(l, filestream_destructor);
    if (!s) {
        ast_module_unref(fmt->module);
        return NULL;
    }
    s->fmt = fmt;
    s->f = bfile;
 
    if (fmt->desc_size)
        s->_private = ((char *)(s + 1)) + fmt->buf_size;
    if (fmt->buf_size)
        s->buf = (char *)(s + 1);
    s->fr.src = fmt->name;
 
    if (ast_format_get_type(fmt->format) == AST_MEDIA_TYPE_AUDIO) {
        s->fr.frametype = AST_FRAME_VOICE;
    } else if (ast_format_get_type(fmt->format) == AST_MEDIA_TYPE_VIDEO) {
        s->fr.frametype = AST_FRAME_VIDEO;
    }
    s->fr.mallocd = 0;
    s->fr.subclass.format = ao2_bump(fmt->format);
 
    return s;
}
 
/*
 * Default implementations of open and rewrite.
 * Only use them if you don't have expensive stuff to do.
 */
enum wrap_fn { WRAP_OPEN, WRAP_REWRITE };
 
static int fn_wrapper(struct ast_filestream *s, const char *comment, enum wrap_fn mode)
{
    struct ast_format_def *f = s->fmt;
    int ret = -1;
    int (*openfn)(struct ast_filestream *s);
 
    if (mode == WRAP_OPEN && (openfn = f->open) && openfn(s))
        ast_log(LOG_WARNING, "Unable to open format %s\n", f->name);
    else if (mode == WRAP_REWRITE && f->rewrite && f->rewrite(s, comment))
        ast_log(LOG_WARNING, "Unable to rewrite format %s\n", f->name);
    else {
        /* preliminary checks succeed. */
        ret = 0;
    }
    return ret;
}
 
static int rewrite_wrapper(struct ast_filestream *s, const char *comment)
{
    return fn_wrapper(s, comment, WRAP_REWRITE);
}
 
static int open_wrapper(struct ast_filestream *s)
{
    return fn_wrapper(s, NULL, WRAP_OPEN);
}
 
enum file_action {
    ACTION_EXISTS = 1, /* return matching format if file exists, 0 otherwise */
    ACTION_DELETE,  /* delete file, return 0 on success, -1 on error */
    ACTION_RENAME,  /* rename file. return 0 on success, -1 on error */
    ACTION_OPEN,
    ACTION_COPY /* copy file. return 0 on success, -1 on error */
};
 
/*!
 * \internal
 * \brief perform various actions on a file. Second argument
 * \note arg2 depends on the command:
 *  unused for DELETE
 *  optional ast_format_cap holding all the formats found for a file, for EXISTS.
 *  destination file name (const char *) for COPY and RENAME
 *  struct ast_channel * for OPEN
 * if fmt is NULL, OPEN will return the first matching entry,
 * whereas other functions will run on all matching entries.
 */
static int filehelper(const char *filename, const void *arg2, const char *fmt, const enum file_action action)
{
    struct ast_format_def *f;
    int res = (action == ACTION_EXISTS) ? 0 : -1;
 
    AST_RWLIST_RDLOCK(&formats);
    /* Check for a specific format */
    AST_RWLIST_TRAVERSE(&formats, f, list) {
        char *ext = NULL;
        char storage[strlen(f->exts) + 1];
        char *stringp;
 
        if (fmt && !exts_compare(f->exts, fmt))
            continue;
 
        /* Look for a file matching the supported extensions.
         * The file must exist, and for OPEN, must match
         * one of the formats supported by the channel.
         */
        strcpy(storage, f->exts); /* safe - this is in the stack so does not need to be freed */
        stringp = storage;
        while ( (ext = strsep(&stringp, "|")) ) {
            struct stat st;
            char *fn = build_filename(filename, ext);
 
            if (fn == NULL)
                continue;
 
            if ( stat(fn, &st) ) { /* file not existent */
                ast_free(fn);
                continue;
            }
            /* for 'OPEN' we need to be sure that the format matches
             * what the channel can process
             */
            if (action == ACTION_OPEN) {
                struct ast_channel *chan = (struct ast_channel *)arg2;
                FILE *bfile;
                struct ast_filestream *s;
 
                if ((ast_format_cmp(ast_channel_writeformat(chan), f->format) == AST_FORMAT_CMP_NOT_EQUAL) &&
                     !(((ast_format_get_type(f->format) == AST_MEDIA_TYPE_AUDIO) && fmt) ||
                      ((ast_format_get_type(f->format) == AST_MEDIA_TYPE_VIDEO) && fmt))) {
                    ast_free(fn);
                    continue;   /* not a supported format */
                }
                if ( (bfile = fopen(fn, "r")) == NULL) {
                    ast_free(fn);
                    continue;   /* cannot open file */
                }
                s = get_filestream(f, bfile);
                if (!s) {
                    fclose(bfile);
                    ast_free(fn);   /* cannot allocate descriptor */
                    continue;
                }
                if (open_wrapper(s)) {
                    ast_free(fn);
                    ast_closestream(s);
                    continue;   /* cannot run open on file */
                }
                if (st.st_size == 0) {
                    ast_log(LOG_WARNING, "File %s detected to have zero size.\n", fn);
                }
                /* ok this is good for OPEN */
                res = 1;    /* found */
                s->lasttimeout = -1;
                s->fmt = f;
                s->trans = NULL;
                s->filename = NULL;
                if (ast_format_get_type(s->fmt->format) == AST_MEDIA_TYPE_AUDIO) {
                    if (ast_channel_stream(chan))
                        ast_closestream(ast_channel_stream(chan));
                    ast_channel_stream_set(chan, s);
                } else {
                    if (ast_channel_vstream(chan))
                        ast_closestream(ast_channel_vstream(chan));
                    ast_channel_vstream_set(chan, s);
                }
                ast_free(fn);
                break;
            }
            switch (action) {
            case ACTION_OPEN:
                break;  /* will never get here */
 
            case ACTION_EXISTS: /* return the matching format */
                /* if arg2 is present, it is a format capabilities structure.
                 * Add this format to the set of formats this file can be played in */
                if (arg2) {
                    ast_format_cap_append((struct ast_format_cap *) arg2, f->format, 0);
                }
                res = 1; /* file does exist and format it exists in is returned in arg2 */
                break;
 
            case ACTION_DELETE:
                if ( (res = unlink(fn)) )
                    ast_log(LOG_WARNING, "unlink(%s) failed: %s\n", fn, strerror(errno));
                break;
 
            case ACTION_RENAME:
            case ACTION_COPY: {
                char *nfn = build_filename((const char *)arg2, ext);
                if (!nfn)
                    ast_log(LOG_WARNING, "Out of memory\n");
                else {
                    res = action == ACTION_COPY ? copy(fn, nfn) : rename(fn, nfn);
                    if (res)
                        ast_log(LOG_WARNING, "%s(%s,%s) failed: %s\n",
                            action == ACTION_COPY ? "copy" : "rename",
                             fn, nfn, strerror(errno));
                    ast_free(nfn);
                }
                }
                break;
 
            default:
                ast_log(LOG_WARNING, "Unknown helper %u\n", action);
            }
            ast_free(fn);
        }
    }
    AST_RWLIST_UNLOCK(&formats);
    return res;
}
 
static int is_absolute_path(const char *filename)
{
    return filename[0] == '/';
}
 
static int is_remote_path(const char *filename)
{
    return strstr(filename, "://") ? 1 : 0;
}
 
/*!
 * \brief test if a file exists for a given format.
 * \note result_cap is OPTIONAL
 * \retval 1 true and result_cap represents format capabilities file exists in.
 * \retval 0 false
 */
static int fileexists_test(const char *filename, const char *fmt, const char *lang,
               char *buf, int buflen, struct ast_format_cap *result_cap)
{
    if (buf == NULL) {
        return 0;
    }
 
    if (is_remote_path(filename) && !ast_media_cache_retrieve(filename, NULL, buf, buflen)) {
        return filehelper(buf, result_cap, NULL, ACTION_EXISTS);
    }
 
    if (ast_language_is_prefix && !is_absolute_path(filename)) { /* new layout */
        if (lang) {
            snprintf(buf, buflen, "%s/%s", lang, filename);
        } else {
            snprintf(buf, buflen, "%s", filename);
        }
    } else { /* old layout */
        strcpy(buf, filename);  /* first copy the full string */
        if (lang) {
            /* insert the language and suffix if needed */
            const char *c = strrchr(filename, '/');
            int offset = c ? c - filename + 1 : 0;  /* points right after the last '/' */
            snprintf(buf + offset, buflen - offset, "%s/%s", lang, filename + offset);
        }
    }
 
    return filehelper(buf, result_cap, fmt, ACTION_EXISTS);
}
 
/*!
 * \brief helper routine to locate a file with a given format
 * and language preference.
 *
 * \note Try preflang, preflang with stripped '_' suffices, or NULL.
 *
 * \note The last parameter(s) point to a buffer of sufficient size,
 * which on success is filled with the matching filename.
 *
 * \param filename Name of the file.
 * \param fmt Format to look for the file in. OPTIONAL
 * \param preflang The preferred language
 * \param buf Returns the matching filename
 * \param buflen Size of the buf
 * \param result_cap OPTIONAL format capabilities result structure
 *        returns what formats the file was found in.
 *
 * \retval 1 true. file exists and result format is set
 * \retval 0 false. file does not exist.
 */
static int fileexists_core(const char *filename, const char *fmt, const char *preflang,
               char *buf, int buflen, struct ast_format_cap *result_cap)
{
    char *lang;
 
    if (buf == NULL) {
        return 0;
    }
 
    /* We try languages in the following order:
     *    preflang (may include dialect and style codes)
     *    lang (preflang without dialect - if any)
     *    <none>
     *    default (unless the same as preflang or lang without dialect)
     */
 
    lang = ast_strdupa(preflang);
 
    /* Try preferred language, including removing any style or dialect codes */
    while (!ast_strlen_zero(lang)) {
        char *end;
 
        if (fileexists_test(filename, fmt, lang, buf, buflen, result_cap)) {
            return 1;
        }
 
        if ((end = strrchr(lang, '_')) != NULL) {
            *end = '\0';
            continue;
        }
 
        break;
    }
 
    /* Try without any language */
    if (fileexists_test(filename, fmt, NULL, buf, buflen, result_cap)) {
        return 1;
    }
 
    /* Finally try the default language unless it was already tried before */
    if ((ast_strlen_zero(preflang) || strcmp(preflang, DEFAULT_LANGUAGE)) && (ast_strlen_zero(lang) || strcmp(lang, DEFAULT_LANGUAGE))) {
        if ((fileexists_test(filename, fmt, DEFAULT_LANGUAGE, buf, buflen, result_cap)) > 0) {
            return 1;
        }
    }
 
    return 0;
}
 
static struct ast_filestream *openstream_internal(struct ast_channel *chan,
    const char *filename, const char *preflang, int asis, int quiet)
{
    /*
     * Use fileexists_core() to find a file in a compatible
     * language and format, set up a suitable translator,
     * and open the stream.
     */
    struct ast_format_cap *file_fmt_cap;
    int res;
    int buflen;
    char *buf;
 
    if (!asis) {
        /* do this first, otherwise we detect the wrong writeformat */
        ast_stopstream(chan);
        if (ast_channel_generator(chan))
            ast_deactivate_generator(chan);
    }
    if (preflang == NULL)
        preflang = "";
    buflen = strlen(preflang) + strlen(filename) + 4;
    buf = ast_alloca(buflen);
 
    if (!(file_fmt_cap = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT))) {
        return NULL;
    }
    if (!fileexists_core(filename, NULL, preflang, buf, buflen, file_fmt_cap) ||
        !ast_format_cap_has_type(file_fmt_cap, AST_MEDIA_TYPE_AUDIO)) {
 
        if (!quiet) {
            ast_log(LOG_WARNING, "File %s does not exist in any format\n", filename);
        }
        ao2_ref(file_fmt_cap, -1);
        return NULL;
    }
 
    /* Set the channel to a format we can work with and save off the previous format. */
    ast_channel_lock(chan);
    ast_channel_set_oldwriteformat(chan, ast_channel_writeformat(chan));
    /* Set the channel to the best format that exists for the file. */
    res = ast_set_write_format_from_cap(chan, file_fmt_cap);
    ast_channel_unlock(chan);
    /* don't need this anymore now that the channel's write format is set. */
    ao2_ref(file_fmt_cap, -1);
 
    if (res == -1) {    /* No format available that works with this channel */
        return NULL;
    }
    res = filehelper(buf, chan, NULL, ACTION_OPEN);
    if (res >= 0)
        return ast_channel_stream(chan);
    return NULL;
}
 
struct ast_filestream *ast_openstream(struct ast_channel *chan, const char *filename, const char *preflang)
{
    return openstream_internal(chan, filename, preflang, 0, 0);
}
 
struct ast_filestream *ast_openstream_full(struct ast_channel *chan,
    const char *filename, const char *preflang, int asis)
{
    return openstream_internal(chan, filename, preflang, asis, 0);
}
 
struct ast_filestream *ast_openvstream(struct ast_channel *chan,
    const char *filename, const char *preflang)
{
    /* As above, but for video. But here we don't have translators
     * so we must enforce a format.
     */
    struct ast_format_cap *nativeformats, *tmp_cap;
    char *buf;
    int buflen;
    int i, fd;
 
    if (preflang == NULL) {
        preflang = "";
    }
    buflen = strlen(preflang) + strlen(filename) + 4;
    buf = ast_alloca(buflen);
 
    ast_channel_lock(chan);
    nativeformats = ao2_bump(ast_channel_nativeformats(chan));
    ast_channel_unlock(chan);
 
    /* is the channel capable of video without translation ?*/
    if (!ast_format_cap_has_type(nativeformats, AST_MEDIA_TYPE_VIDEO)) {
        ao2_cleanup(nativeformats);
        return NULL;
    }
    if (!(tmp_cap = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT))) {
        ao2_cleanup(nativeformats);
        return NULL;
    }
    /* Video is supported, so see what video formats exist for this file */
    if (!fileexists_core(filename, NULL, preflang, buf, buflen, tmp_cap)) {
        ao2_ref(tmp_cap, -1);
        ao2_cleanup(nativeformats);
        return NULL;
    }
 
    /* iterate over file formats and pick the first one compatible with the channel's native formats */
    for (i = 0; i < ast_format_cap_count(tmp_cap); ++i) {
        struct ast_format *format = ast_format_cap_get_format(tmp_cap, i);
 
        if ((ast_format_get_type(format) != AST_MEDIA_TYPE_VIDEO) ||
            !ast_format_cap_iscompatible(nativeformats, tmp_cap)) {
            ao2_ref(format, -1);
            continue;
        }
 
        fd = filehelper(buf, chan, ast_format_get_name(format), ACTION_OPEN);
        if (fd >= 0) {
            ao2_ref(format, -1);
            ao2_ref(tmp_cap, -1);
            ao2_cleanup(nativeformats);
            return ast_channel_vstream(chan);
        }
        ast_log(LOG_WARNING, "File %s has video but couldn't be opened\n", filename);
        ao2_ref(format, -1);
    }
    ao2_ref(tmp_cap, -1);
    ao2_cleanup(nativeformats);
 
    return NULL;
}
 
static struct ast_frame *read_frame(struct ast_filestream *s, int *whennext)
{
    struct ast_frame *fr, *new_fr;
 
    if (!s || !s->fmt) {
        return NULL;
    }
 
    if (!(fr = s->fmt->read(s, whennext))) {
        return NULL;
    }
 
    if (!(new_fr = ast_frisolate(fr))) {
        ast_frfree(fr);
        return NULL;
    }
 
    if (new_fr != fr) {
        ast_frfree(fr);
        fr = new_fr;
    }
 
    return fr;
}
 
struct ast_frame *ast_readframe(struct ast_filestream *s)
{
    int whennext = 0;
 
    return read_frame(s, &whennext);
}
 
enum fsread_res {
    FSREAD_FAILURE,
    FSREAD_SUCCESS_SCHED,
    FSREAD_SUCCESS_NOSCHED,
};
 
static int ast_fsread_audio(const void *data);
 
static enum fsread_res ast_readaudio_callback(struct ast_filestream *s)
{
    int whennext = 0;
 
    while (!whennext) {
        struct ast_frame *fr;
 
        if (s->orig_chan_name && strcasecmp(ast_channel_name(s->owner), s->orig_chan_name)) {
            goto return_failure;
        }
 
        fr = read_frame(s, &whennext);
 
        if (!fr /* stream complete */ || ast_write(s->owner, fr) /* error writing */) {
            if (fr) {
                ast_debug(2, "Failed to write frame\n");
                ast_frfree(fr);
            }
            goto return_failure;
        }
 
        if (fr) {
            ast_frfree(fr);
        }
    }
 
    if (whennext != s->lasttimeout) {
        if (ast_channel_timingfd(s->owner) > -1) {
            float samp_rate = (float) ast_format_get_sample_rate(s->fmt->format);
            unsigned int rate;
 
            rate = (unsigned int) roundf(samp_rate / ((float) whennext));
 
            ast_settimeout_full(s->owner, rate, ast_fsread_audio, s, 1);
        } else {
            ast_channel_streamid_set(s->owner, ast_sched_add(ast_channel_sched(s->owner), whennext / (ast_format_get_sample_rate(s->fmt->format) / 1000), ast_fsread_audio, s));
        }
        s->lasttimeout = whennext;
        return FSREAD_SUCCESS_NOSCHED;
    }
    return FSREAD_SUCCESS_SCHED;
 
return_failure:
    ast_channel_streamid_set(s->owner, -1);
    ast_settimeout(s->owner, 0, NULL, NULL);
    return FSREAD_FAILURE;
}
 
static int ast_fsread_audio(const void *data)
{
    struct ast_filestream *fs = (struct ast_filestream *)data;
    enum fsread_res res;
 
    res = ast_readaudio_callback(fs);
 
    if (res == FSREAD_SUCCESS_SCHED)
        return 1;
 
    return 0;
}
 
static int ast_fsread_video(const void *data);
 
static enum fsread_res ast_readvideo_callback(struct ast_filestream *s)
{
    int whennext = 0;
 
    while (!whennext) {
        struct ast_frame *fr = read_frame(s, &whennext);
 
        if (!fr /* stream complete */ || ast_write(s->owner, fr) /* error writing */) {
            if (fr) {
                ast_debug(2, "Failed to write frame\n");
                ast_frfree(fr);
            }
            ast_channel_vstreamid_set(s->owner, -1);
            return FSREAD_FAILURE;
        }
 
        if (fr) {
            ast_frfree(fr);
        }
    }
 
    if (whennext != s->lasttimeout) {
        ast_channel_vstreamid_set(s->owner, ast_sched_add(ast_channel_sched(s->owner), whennext / (ast_format_get_sample_rate(s->fmt->format) / 1000), ast_fsread_video, s));
        s->lasttimeout = whennext;
        return FSREAD_SUCCESS_NOSCHED;
    }
 
    return FSREAD_SUCCESS_SCHED;
}
 
static int ast_fsread_video(const void *data)
{
    struct ast_filestream *fs = (struct ast_filestream *)data;
    enum fsread_res res;
 
    res = ast_readvideo_callback(fs);
 
    if (res == FSREAD_SUCCESS_SCHED)
        return 1;
 
    return 0;
}
 
int ast_applystream(struct ast_channel *chan, struct ast_filestream *s)
{
    s->owner = chan;
    return 0;
}
 
int ast_playstream(struct ast_filestream *s)
{
    enum fsread_res res;
 
    if (ast_format_get_type(s->fmt->format) == AST_MEDIA_TYPE_AUDIO)
        res = ast_readaudio_callback(s);
    else
        res = ast_readvideo_callback(s);
 
    return (res == FSREAD_FAILURE) ? -1 : 0;
}
 
int ast_seekstream(struct ast_filestream *fs, off_t sample_offset, int whence)
{
    return fs->fmt->seek(fs, sample_offset, whence);
}
 
int ast_truncstream(struct ast_filestream *fs)
{
    return fs->fmt->trunc(fs);
}
 
off_t ast_tellstream(struct ast_filestream *fs)
{
    return fs->fmt->tell(fs);
}
 
int ast_ratestream(struct ast_filestream *fs)
{
    return ast_format_get_sample_rate(fs->fmt->format);
}
 
int ast_stream_fastforward(struct ast_filestream *fs, off_t ms)
{
    return ast_seekstream(fs, ms * DEFAULT_SAMPLES_PER_MS, SEEK_CUR);
}
 
int ast_stream_rewind(struct ast_filestream *fs, off_t ms)
{
    off_t offset = ast_tellstream(fs);
    if (ms * DEFAULT_SAMPLES_PER_MS > offset) {
        /* Don't even bother asking the file format to seek to a negative offset... */
        ast_debug(1, "Restarting, rather than seeking to negative offset %ld\n", (long) (offset - (ms * DEFAULT_SAMPLES_PER_MS)));
        return ast_seekstream(fs, 0, SEEK_SET);
    }
    return ast_seekstream(fs, -ms * DEFAULT_SAMPLES_PER_MS, SEEK_CUR);
}
 
int ast_closestream(struct ast_filestream *f)
{
    /* This used to destroy the filestream, but it now just decrements a refcount.
     * We close the stream in order to quit queuing frames now, because we might
     * change the writeformat, which could result in a subsequent write error, if
     * the format is different. */
    if (f == NULL) {
        return 0;
    }
    filestream_close(f);
    ao2_ref(f, -1);
    return 0;
}
 
 
/*
 * Look the various language-specific places where a file could exist.
 */
int ast_fileexists(const char *filename, const char *fmt, const char *preflang)
{
    char *buf;
    int buflen;
 
    if (preflang == NULL)
        preflang = "";
    buflen = strlen(preflang) + strlen(filename) + 4;   /* room for everything */
    buf = ast_alloca(buflen);
    return fileexists_core(filename, fmt, preflang, buf, buflen, NULL) ? 1 : 0;
}
 
int ast_filedelete(const char *filename, const char *fmt)
{
    return filehelper(filename, NULL, fmt, ACTION_DELETE);
}
 
int ast_filerename(const char *filename, const char *filename2, const char *fmt)
{
    return filehelper(filename, filename2, fmt, ACTION_RENAME);
}
 
int ast_filecopy(const char *filename, const char *filename2, const char *fmt)
{
    return filehelper(filename, filename2, fmt, ACTION_COPY);
}
 
static int __ast_file_read_dirs(const char *path, ast_file_on_file on_file,
                void *obj, int max_depth)
{
    DIR *dir;
    struct dirent *entry;
    int res;
 
    if (!(dir = opendir(path))) {
        ast_log(LOG_ERROR, "Error opening directory - %s: %s\n",
            path, strerror(errno));
        return -1;
    }
 
    --max_depth;
 
    res = 0;
 
    while ((entry = readdir(dir)) != NULL && !errno) {
        int is_file = 0;
        int is_dir = 0;
        RAII_VAR(char *, full_path, NULL, ast_free);
 
        if (!strcmp(entry->d_name, ".") || !strcmp(entry->d_name, "..")) {
            continue;
        }
 
/*
 * If the dirent structure has a d_type use it to determine if we are dealing with
 * a file or directory. Unfortunately if it doesn't have it, or if the type is
 * unknown, or a link then we'll need to use the stat function instead.
 */
#ifdef _DIRENT_HAVE_D_TYPE
        if (entry->d_type != DT_UNKNOWN && entry->d_type != DT_LNK) {
            is_file = entry->d_type == DT_REG;
            is_dir = entry->d_type == DT_DIR;
        } else
#endif
        {
            struct stat statbuf;
 
            /*
             * Don't use alloca or we risk blowing out the stack if recursing
             * into subdirectories.
             */
            full_path = ast_malloc(strlen(path) + strlen(entry->d_name) + 2);
            if (!full_path) {
                return -1;
            }
            sprintf(full_path, "%s/%s", path, entry->d_name);
 
            if (stat(full_path, &statbuf)) {
                ast_log(LOG_ERROR, "Error reading path stats - %s: %s\n",
                    full_path, strerror(errno));
                /*
                 * Output an error, but keep going. It could just be
                 * a broken link and other files could be fine.
                 */
                continue;
            }
 
            is_file = S_ISREG(statbuf.st_mode);
            is_dir = S_ISDIR(statbuf.st_mode);
        }
 
        if (is_file) {
            /* If the handler returns non-zero then stop */
            if ((res = on_file(path, entry->d_name, obj))) {
                break;
            }
            /* Otherwise move on to next item in directory */
            continue;
        }
 
        if (!is_dir) {
            ast_debug(5, "Skipping %s: not a regular file or directory\n", full_path);
            continue;
        }
 
        /* Only re-curse into sub-directories if not at the max depth */
        if (max_depth != 0) {
            if (!full_path) {
                /* Don't use alloca.  See note above. */
                full_path = ast_malloc(strlen(path) + strlen(entry->d_name) + 2);
                if (!full_path) {
                    return -1;
                }
                sprintf(full_path, "%s/%s", path, entry->d_name);
            }
 
            if ((res = __ast_file_read_dirs(full_path, on_file, obj, max_depth))) {
                break;
            }
        }
    }
 
    closedir(dir);
 
    if (!res && errno) {
        ast_log(LOG_ERROR, "Error while reading directories - %s: %s\n",
            path, strerror(errno));
        res = -1;
    }
 
    return res;
}
 
#if !defined(__GLIBC__)
/*!
 * \brief Lock to hold when iterating over directories.
 *
 * Currently, 'readdir' is not required to be thread-safe. In most modern implementations
 * it should be safe to make concurrent calls into 'readdir' that specify different directory
 * streams (glibc would be one of these). However, since it is potentially unsafe for some
 * implementations we'll use our own locking in order to achieve synchronization for those.
 */
AST_MUTEX_DEFINE_STATIC(read_dirs_lock);
#endif
 
int ast_file_read_dirs(const char *dir_name, ast_file_on_file on_file, void *obj, int max_depth)
{
    int res;
 
    errno = 0;
 
#if !defined(__GLIBC__)
    ast_mutex_lock(&read_dirs_lock);
#endif
 
    res = __ast_file_read_dirs(dir_name, on_file, obj, max_depth);
 
#if !defined(__GLIBC__)
    ast_mutex_unlock(&read_dirs_lock);
#endif
 
    return res;
}
 
int ast_streamfile(struct ast_channel *chan, const char *filename,
    const char *preflang)
{
    struct ast_filestream *fs = NULL;
    struct ast_filestream *vfs = NULL;
    off_t pos;
    int seekattempt;
    int res;
    char custom_filename[256];
    char *tmp_filename;
 
    /* If file with the same name exists in /var/lib/asterisk/sounds/custom directory, use that file.
     * Otherwise, use the original file*/
 
    if (ast_opt_sounds_search_custom && !is_absolute_path(filename)) {
        memset(custom_filename, 0, sizeof(custom_filename));
        snprintf(custom_filename, sizeof(custom_filename), "custom/%s", filename);
        fs = openstream_internal(chan, filename, preflang, 0, 1); /* open stream, do not warn for missing files */
        if (fs) {
            tmp_filename = custom_filename;
            ast_debug(3, "Found file %s in custom directory\n", filename);
        }
    }
 
    if (!fs) {
        fs = ast_openstream(chan, filename, preflang);
        if (!fs) {
            struct ast_str *codec_buf = ast_str_alloca(AST_FORMAT_CAP_NAMES_LEN);
            ast_channel_lock(chan);
            ast_log(LOG_WARNING, "Unable to open %s (format %s): %s\n",
                    filename, ast_format_cap_get_names(ast_channel_nativeformats(chan), &codec_buf), strerror(errno));
            ast_channel_unlock(chan);
            return -1;
        }
        tmp_filename = (char *)filename;
    }
 
    /* check to see if there is any data present (not a zero length file),
     * done this way because there is no where for ast_openstream_full to
     * return the file had no data. */
    pos = ftello(fs->f);
    seekattempt = fseeko(fs->f, -1, SEEK_END);
    if (seekattempt) {
        if (errno == EINVAL) {
            /* Zero-length file, as opposed to a pipe */
            return 0;
        } else {
            ast_seekstream(fs, 0, SEEK_SET);
        }
    } else {
        fseeko(fs->f, pos, SEEK_SET);
    }
 
    vfs = ast_openvstream(chan, tmp_filename, preflang);
    if (vfs) {
        ast_debug(1, "Ooh, found a video stream, too, format %s\n", ast_format_get_name(vfs->fmt->format));
    }
 
    if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_MASQ_NOSTREAM))
        fs->orig_chan_name = ast_strdup(ast_channel_name(chan));
    if (ast_applystream(chan, fs))
        return -1;
    if (vfs && ast_applystream(chan, vfs))
        return -1;
    ast_test_suite_event_notify("PLAYBACK", "Message: %s\r\nChannel: %s", tmp_filename, ast_channel_name(chan));
    res = ast_playstream(fs);
    if (!res && vfs)
        res = ast_playstream(vfs);
 
    if (VERBOSITY_ATLEAST(3)) {
        ast_channel_lock(chan);
        ast_verb(3, "<%s> Playing '%s.%s' (language '%s')\n", ast_channel_name(chan), tmp_filename, ast_format_get_name(ast_channel_writeformat(chan)), preflang ? preflang : "default");
        ast_channel_unlock(chan);
    }
 
    return res;
}
 
struct ast_filestream *ast_readfile(const char *filename, const char *type, const char *comment, int flags, int check, mode_t mode)
{
    FILE *bfile;
    struct ast_format_def *f;
    struct ast_filestream *fs = NULL;
    char *fn;
    int format_found = 0;
 
    AST_RWLIST_RDLOCK(&formats);
 
    AST_RWLIST_TRAVERSE(&formats, f, list) {
        fs = NULL;
        if (!exts_compare(f->exts, type))
            continue;
        else
            format_found = 1;
 
        fn = build_filename(filename, type);
        if (!fn) {
            continue;
        }
        errno = 0;
        bfile = fopen(fn, "r");
 
        if (!bfile || (fs = get_filestream(f, bfile)) == NULL || open_wrapper(fs) ) {
            ast_log(LOG_WARNING, "Unable to open %s\n", fn);
            if (fs) {
                ast_closestream(fs);
            }
            fs = NULL;
            bfile = NULL;
            ast_free(fn);
            break;
        }
        /* found it */
        fs->trans = NULL;
        fs->fmt = f;
        fs->flags = flags;
        fs->mode = mode;
        fs->filename = ast_strdup(filename);
        fs->vfs = NULL;
        ast_free(fn);
        break;
    }
 
    AST_RWLIST_UNLOCK(&formats);
    if (!format_found)
        ast_log(LOG_WARNING, "No such format '%s'\n", type);
 
    return fs;
}
 
struct ast_filestream *ast_writefile(const char *filename, const char *type, const char *comment, int flags, int check, mode_t mode)
{
    int fd, myflags = 0;
    /* compiler claims this variable can be used before initialization... */
    FILE *bfile = NULL;
    struct ast_format_def *f;
    struct ast_filestream *fs = NULL;
    char *buf = NULL;
    size_t size = 0;
    int format_found = 0;
 
    AST_RWLIST_RDLOCK(&formats);
 
    /* set the O_TRUNC flag if and only if there is no O_APPEND specified */
    /* We really can't use O_APPEND as it will break WAV header updates */
    if (flags & O_APPEND) {
        flags &= ~O_APPEND;
    } else {
        myflags = O_TRUNC;
    }
 
    myflags |= O_WRONLY | O_CREAT;
 
    /* XXX need to fix this - we should just do the fopen,
     * not open followed by fdopen()
     */
    AST_RWLIST_TRAVERSE(&formats, f, list) {
        char *fn, *orig_fn = NULL;
        if (fs)
            break;
 
        if (!exts_compare(f->exts, type))
            continue;
        else
            format_found = 1;
 
        fn = build_filename(filename, type);
        if (!fn) {
            continue;
        }
        fd = open(fn, flags | myflags, mode);
        if (fd > -1) {
            /* fdopen() the resulting file stream */
            bfile = fdopen(fd, ((flags | myflags) & O_RDWR) ? "w+" : "w");
            if (!bfile) {
                ast_log(LOG_WARNING, "Whoa, fdopen failed: %s!\n", strerror(errno));
                close(fd);
                fd = -1;
            }
        }
 
        if (ast_opt_cache_record_files && (fd > -1)) {
            char *c;
 
            fclose(bfile);  /* this also closes fd */
            /*
              We touch orig_fn just as a place-holder so other things (like vmail) see the file is there.
              What we are really doing is writing to record_cache_dir until we are done then we will mv the file into place.
            */
            orig_fn = ast_strdup(fn);
            for (c = fn; *c; c++)
                if (*c == '/')
                    *c = '_';
 
            size = strlen(fn) + strlen(record_cache_dir) + 2;
            buf = ast_malloc(size);
            strcpy(buf, record_cache_dir);
            strcat(buf, "/");
            strcat(buf, fn);
            ast_free(fn);
            fn = buf;
            fd = open(fn, flags | myflags, mode);
            if (fd > -1) {
                /* fdopen() the resulting file stream */
                bfile = fdopen(fd, ((flags | myflags) & O_RDWR) ? "w+" : "w");
                if (!bfile) {
                    ast_log(LOG_WARNING, "Whoa, fdopen failed: %s!\n", strerror(errno));
                    close(fd);
                    fd = -1;
                }
            }
        }
        if (fd > -1) {
            errno = 0;
            fs = get_filestream(f, bfile);
            if (fs) {
                if ((fs->write_buffer = ast_malloc(32768))) {
                    setvbuf(fs->f, fs->write_buffer, _IOFBF, 32768);
                }
            }
            if (!fs || rewrite_wrapper(fs, comment)) {
                ast_log(LOG_WARNING, "Unable to rewrite %s\n", fn);
                close(fd);
                if (orig_fn) {
                    unlink(fn);
                    unlink(orig_fn);
                    ast_free(orig_fn);
                }
                if (fs) {
                    ast_closestream(fs);
                    fs = NULL;
                }
                /*
                 * 'fn' was has either been allocated from build_filename, or that was freed
                 * and now 'fn' points to memory allocated for 'buf'. Either way the memory
                 * now needs to be released.
                 */
                ast_free(fn);
                continue;
            }
            fs->trans = NULL;
            fs->fmt = f;
            fs->flags = flags;
            fs->mode = mode;
            if (orig_fn) {
                fs->realfilename = orig_fn;
                fs->filename = fn;
                /*
                 * The above now manages the memory allocated for 'orig_fn' and 'fn', so
                 * set them to NULL, so they don't get released at the end of the loop.
                 */
                orig_fn = NULL;
                fn = NULL;
            } else {
                fs->realfilename = NULL;
                fs->filename = ast_strdup(filename);
            }
            fs->vfs = NULL;
            /* If truncated, we'll be at the beginning; if not truncated, then append */
            f->seek(fs, 0, SEEK_END);
        } else if (errno != EEXIST) {
            ast_log(LOG_WARNING, "Unable to open file %s: %s\n", fn, strerror(errno));
            if (orig_fn)
                unlink(orig_fn);
        }
        /* Free 'fn', or if 'fn' points to 'buf' then free 'buf' */
        ast_free(fn);
        ast_free(orig_fn);
    }
 
    AST_RWLIST_UNLOCK(&formats);
 
    if (!format_found)
        ast_log(LOG_WARNING, "No such format '%s'\n", type);
 
    return fs;
}
 
static void waitstream_control(struct ast_channel *c,
        enum ast_waitstream_fr_cb_values type,
        ast_waitstream_fr_cb cb,
        int skip_ms)
{
    switch (type)
    {
    case AST_WAITSTREAM_CB_FASTFORWARD:
        {
            int eoftest;
            ast_stream_fastforward(ast_channel_stream(c), skip_ms);
            eoftest = fgetc(ast_channel_stream(c)->f);
            if (feof(ast_channel_stream(c)->f)) {
                ast_stream_rewind(ast_channel_stream(c), skip_ms);
            } else {
                ungetc(eoftest, ast_channel_stream(c)->f);
            }
        }
        break;
    case AST_WAITSTREAM_CB_REWIND:
        ast_stream_rewind(ast_channel_stream(c), skip_ms);
        break;
    default:
        break;
    }
 
    if (cb) {
        long ms_len = ast_tellstream(ast_channel_stream(c)) / (ast_format_get_sample_rate(ast_channel_stream(c)->fmt->format) / 1000);
        cb(c, ms_len, type);
    }
 
    ast_test_suite_event_notify("PLAYBACK","Channel: %s\r\n"
        "Control: %s\r\n"
        "SkipMs: %d\r\n",
        ast_channel_name(c),
        (type == AST_WAITSTREAM_CB_FASTFORWARD) ? "FastForward" : "Rewind",
        skip_ms);
}
 
/*!
 * \brief the core of all waitstream() functions
 */
static int waitstream_core(struct ast_channel *c,
    const char *breakon,
    const char *forward,
    const char *reverse,
    int skip_ms,
    int audiofd,
    int cmdfd,
    const char *context,
    ast_waitstream_fr_cb cb)
{
    const char *orig_chan_name = NULL;
 
    int err = 0;
 
    if (!breakon)
        breakon = "";
    if (!forward)
        forward = "";
    if (!reverse)
        reverse = "";
 
    /* Switch the channel to end DTMF frame only. waitstream_core doesn't care about the start of DTMF. */
    ast_channel_set_flag(c, AST_FLAG_END_DTMF_ONLY);
 
    if (ast_test_flag(ast_channel_flags(c), AST_FLAG_MASQ_NOSTREAM))
        orig_chan_name = ast_strdupa(ast_channel_name(c));
 
    if (ast_channel_stream(c) && cb) {
        long ms_len = ast_tellstream(ast_channel_stream(c)) / (ast_format_get_sample_rate(ast_channel_stream(c)->fmt->format) / 1000);
        cb(c, ms_len, AST_WAITSTREAM_CB_START);
    }
 
    while (ast_channel_stream(c)) {
        int res;
        int ms;
 
        if (orig_chan_name && strcasecmp(orig_chan_name, ast_channel_name(c))) {
            ast_stopstream(c);
            err = 1;
            break;
        }
 
        ms = ast_sched_wait(ast_channel_sched(c));
 
        if (ms < 0 && !ast_channel_timingfunc(c)) {
            ast_stopstream(c);
            break;
        }
        if (ms < 0)
            ms = 1000;
        if (cmdfd < 0) {
            res = ast_waitfor(c, ms);
            if (res < 0) {
                ast_log(LOG_WARNING, "Select failed (%s)\n", strerror(errno));
                ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
                return res;
            }
        } else {
            int outfd;
            struct ast_channel *rchan = ast_waitfor_nandfds(&c, 1, &cmdfd, (cmdfd > -1) ? 1 : 0, NULL, &outfd, &ms);
            if (!rchan && (outfd < 0) && (ms)) {
                /* Continue */
                if (errno == EINTR)
                    continue;
                ast_log(LOG_WARNING, "Wait failed (%s)\n", strerror(errno));
                ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
                return -1;
            } else if (outfd > -1) { /* this requires cmdfd set */
                /* The FD we were watching has something waiting */
                ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
                return 1;
            }
            /* if rchan is set, it is 'c' */
            res = rchan ? 1 : 0; /* map into 'res' values */
        }
        if (res > 0) {
            struct ast_frame *fr = ast_read(c);
            if (!fr) {
                ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
                return -1;
            }
            switch (fr->frametype) {
            case AST_FRAME_DTMF_END:
                if (context) {
                    const char exten[2] = { fr->subclass.integer, '\0' };
                    if (ast_exists_extension(c, context, exten, 1,
                        S_COR(ast_channel_caller(c)->id.number.valid, ast_channel_caller(c)->id.number.str, NULL))) {
                        res = fr->subclass.integer;
                        ast_frfree(fr);
                        ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
                        return res;
                    }
                } else {
                    res = fr->subclass.integer;
                    if (strchr(forward, res)) {
                        waitstream_control(c, AST_WAITSTREAM_CB_FASTFORWARD, cb, skip_ms);
                    } else if (strchr(reverse, res)) {
                        waitstream_control(c, AST_WAITSTREAM_CB_REWIND, cb, skip_ms);
                    } else if (strchr(breakon, res)) {
                        ast_test_suite_event_notify("PLAYBACK","Channel: %s\r\n"
                            "Control: %s\r\n",
                            ast_channel_name(c),
                            "Break");
 
                        ast_frfree(fr);
                        ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
                        return res;
                    }
                }
                break;
            case AST_FRAME_CONTROL:
                switch (fr->subclass.integer) {
                case AST_CONTROL_STREAM_STOP:
                case AST_CONTROL_STREAM_SUSPEND:
                case AST_CONTROL_STREAM_RESTART:
                    /* Fall-through and break out */
                    ast_test_suite_event_notify("PLAYBACK","Channel: %s\r\n"
                        "Control: %s\r\n",
                        ast_channel_name(c),
                        "Break");
                    res = fr->subclass.integer;
                    ast_frfree(fr);
                    ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
                    return res;
                case AST_CONTROL_STREAM_REVERSE:
                    if (!skip_ms) {
                        skip_ms = 3000;
                    }
                    waitstream_control(c, AST_WAITSTREAM_CB_REWIND, cb, skip_ms);
                    break;
                case AST_CONTROL_STREAM_FORWARD:
                    if (!skip_ms) {
                        skip_ms = 3000;
                    }
                    waitstream_control(c, AST_WAITSTREAM_CB_FASTFORWARD, cb, skip_ms);
                    break;
                case AST_CONTROL_HANGUP:
                case AST_CONTROL_BUSY:
                case AST_CONTROL_CONGESTION:
                    ast_frfree(fr);
                    ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
                    return -1;
                case AST_CONTROL_PROGRESS:
                case AST_CONTROL_RINGING:
                case AST_CONTROL_ANSWER:
                case AST_CONTROL_VIDUPDATE:
                case AST_CONTROL_SRCUPDATE:
                case AST_CONTROL_SRCCHANGE:
                case AST_CONTROL_HOLD:
                case AST_CONTROL_UNHOLD:
                case AST_CONTROL_CONNECTED_LINE:
                case AST_CONTROL_REDIRECTING:
                case AST_CONTROL_AOC:
                case AST_CONTROL_UPDATE_RTP_PEER:
                case AST_CONTROL_PVT_CAUSE_CODE:
                case AST_CONTROL_FLASH:
                case AST_CONTROL_WINK:
                case -1:
                    /* Unimportant */
                    break;
                default:
                    ast_log(LOG_WARNING, "Unexpected control subclass '%d'\n", fr->subclass.integer);
                }
                break;
            case AST_FRAME_VOICE:
                /* Write audio if appropriate */
                if (audiofd > -1) {
                    if (write(audiofd, fr->data.ptr, fr->datalen) < 0) {
                        ast_log(LOG_WARNING, "write() failed: %s\n", strerror(errno));
                    }
                }
            default:
                /* Ignore all others */
                break;
            }
            ast_frfree(fr);
        }
        ast_sched_runq(ast_channel_sched(c));
    }
 
    ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
 
    return (err || ast_channel_softhangup_internal_flag(c)) ? -1 : 0;
}
 
int ast_waitstream_fr_w_cb(struct ast_channel *c,
    const char *breakon,
    const char *forward,
    const char *reverse,
    int ms,
    ast_waitstream_fr_cb cb)
{
    return waitstream_core(c, breakon, forward, reverse, ms,
        -1 /* no audiofd */, -1 /* no cmdfd */, NULL /* no context */, cb);
}
 
int ast_waitstream_fr(struct ast_channel *c, const char *breakon, const char *forward, const char *reverse, int ms)
{
    return waitstream_core(c, breakon, forward, reverse, ms,
        -1 /* no audiofd */, -1 /* no cmdfd */, NULL /* no context */, NULL /* no callback */);
}
 
/*! \internal
 * \brief Clean up the return value of a waitstream call
 *
 * It's possible for a control frame to come in from an external source and break the
 * playback. From a consumer of most ast_waitstream_* function callers, this should
 * appear like normal playback termination, i.e., return 0 and not the value of the
 * control frame.
 */
static int sanitize_waitstream_return(int return_value)
{
    switch (return_value) {
    case AST_CONTROL_STREAM_STOP:
    case AST_CONTROL_STREAM_SUSPEND:
    case AST_CONTROL_STREAM_RESTART:
        /* Fall through and set return_value to 0 */
        return_value = 0;
        break;
    default:
        /* Do nothing */
        break;
    }
 
    return return_value;
}
 
int ast_waitstream(struct ast_channel *c, const char *breakon)
{
    int res;
 
    res = waitstream_core(c, breakon, NULL, NULL, 0, -1, -1, NULL, NULL /* no callback */);
 
    return sanitize_waitstream_return(res);
}
 
int ast_waitstream_full(struct ast_channel *c, const char *breakon, int audiofd, int cmdfd)
{
    int res;
 
    res = waitstream_core(c, breakon, NULL, NULL, 0,
        audiofd, cmdfd, NULL /* no context */, NULL /* no callback */);
 
    return sanitize_waitstream_return(res);
}
 
int ast_waitstream_exten(struct ast_channel *c, const char *context)
{
    int res;
 
    /* Waitstream, with return in the case of a valid 1 digit extension */
    /* in the current or specified context being pressed */
    if (!context)
        context = ast_channel_context(c);
    res = waitstream_core(c, NULL, NULL, NULL, 0,
        -1, -1, context, NULL /* no callback */);
 
    return sanitize_waitstream_return(res);
}
 
/*
 * if the file name is non-empty, try to play it.
 * Return 0 if success, -1 if error, digit if interrupted by a digit.
 * If digits == "" then we can simply check for non-zero.
 */
int ast_stream_and_wait(struct ast_channel *chan, const char *file, const char *digits)
{
    int res = 0;
    if (!ast_strlen_zero(file)) {
        res = ast_streamfile(chan, file, ast_channel_language(chan));
        if (!res) {
            res = ast_waitstream(chan, digits);
        }
    }
    if (res == -1) {
        ast_stopstream(chan);
    }
 
    return res;
}
 
char *ast_format_str_reduce(char *fmts)
{
    struct ast_format_def *f;
    struct ast_format_def *fmts_ptr[AST_MAX_FORMATS];
    char *fmts_str[AST_MAX_FORMATS];
    char *stringp, *type;
    char *orig = fmts;
    int i, j, x, first, found = 0;
    int len = strlen(fmts) + 1;
    int res;
 
    if (AST_RWLIST_RDLOCK(&formats)) {
        ast_log(LOG_WARNING, "Unable to lock format list\n");
        return NULL;
    }
 
    stringp = ast_strdupa(fmts);
 
    for (x = 0; (type = strsep(&stringp, "|")) && x < AST_MAX_FORMATS; x++) {
        AST_RWLIST_TRAVERSE(&formats, f, list) {
            if (exts_compare(f->exts, type)) {
                found = 1;
                break;
            }
        }
 
        fmts_str[x] = type;
        if (found) {
            fmts_ptr[x] = f;
        } else {
            fmts_ptr[x] = NULL;
        }
    }
    AST_RWLIST_UNLOCK(&formats);
 
    first = 1;
    for (i = 0; i < x; i++) {
        /* ignore invalid entries */
        if (!fmts_ptr[i]) {
            ast_log(LOG_WARNING, "ignoring unknown format '%s'\n", fmts_str[i]);
            continue;
        }
 
        /* special handling for the first entry */
        if (first) {
            res = snprintf(fmts, len, "%s", fmts_str[i]);
            fmts += res;
            len -= res;
            first = 0;
            continue;
        }
 
        found = 0;
        for (j = 0; j < i; j++) {
            /* this is a duplicate */
            if (fmts_ptr[j] == fmts_ptr[i]) {
                found = 1;
                break;
            }
        }
 
        if (!found) {
            res = snprintf(fmts, len, "|%s", fmts_str[i]);
            fmts += res;
            len -= res;
        }
    }
 
    if (first) {
        ast_log(LOG_WARNING, "no known formats found in format list (%s)\n", orig);
        return NULL;
    }
 
    return orig;
}
 
static char *handle_cli_core_show_file_formats(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
#define FORMAT "%-10s %-10s %-20s\n"
#define FORMAT2 "%-10s %-10s %-20s\n"
    struct ast_format_def *f;
    int count_fmt = 0;
 
    switch (cmd) {
    case CLI_INIT:
        e->command = "core show file formats";
        e->usage =
            "Usage: core show file formats\n"
            "       Displays currently registered file formats (if any).\n";
        return NULL;
    case CLI_GENERATE:
        return NULL;
    }
 
    if (a->argc != 4)
        return CLI_SHOWUSAGE;
 
    ast_cli(a->fd, FORMAT, "Format", "Name", "Extensions");
    ast_cli(a->fd, FORMAT, "------", "----", "----------");
 
    AST_RWLIST_RDLOCK(&formats);
    AST_RWLIST_TRAVERSE(&formats, f, list) {
        ast_cli(a->fd, FORMAT2, ast_format_get_name(f->format), f->name, f->exts);
        count_fmt++;
    }
    AST_RWLIST_UNLOCK(&formats);
    ast_cli(a->fd, "%d file formats registered.\n", count_fmt);
    return CLI_SUCCESS;
#undef FORMAT
#undef FORMAT2
}
 
struct ast_format *ast_get_format_for_file_ext(const char *file_ext)
{
    struct ast_format_def *f;
    SCOPED_RDLOCK(lock, &formats.lock);
    AST_RWLIST_TRAVERSE(&formats, f, list) {
        if (exts_compare(f->exts, file_ext)) {
            return f->format;
        }
    }
 
    return NULL;
}
 
int ast_get_extension_for_mime_type(const char *mime_type, char *buffer, size_t capacity)
{
    struct ast_format_def *f;
    SCOPED_RDLOCK(lock, &formats.lock);
 
    ast_assert(buffer && capacity);
 
    AST_RWLIST_TRAVERSE(&formats, f, list) {
        if (type_in_list(f->mime_types, mime_type, strcasecmp)) {
            size_t item_len = strcspn(f->exts, "|");
            size_t bytes_written = snprintf(buffer, capacity, ".%.*s", (int) item_len, f->exts);
            if (bytes_written < capacity) {
                /* Only return success if we didn't truncate */
                return 1;
            }
        }
    }
 
    return 0;
}
 
static struct ast_cli_entry cli_file[] = {
    AST_CLI_DEFINE(handle_cli_core_show_file_formats, "Displays file formats")
};
 
static void file_shutdown(void)
{
    ast_cli_unregister_multiple(cli_file, ARRAY_LEN(cli_file));
    STASIS_MESSAGE_TYPE_CLEANUP(ast_format_register_type);
    STASIS_MESSAGE_TYPE_CLEANUP(ast_format_unregister_type);
}
 
int ast_file_init(void)
{
    STASIS_MESSAGE_TYPE_INIT(ast_format_register_type);
    STASIS_MESSAGE_TYPE_INIT(ast_format_unregister_type);
    ast_cli_register_multiple(cli_file, ARRAY_LEN(cli_file));
    ast_register_cleanup(file_shutdown);
    return 0;
}