stored.c

Go to the documentation of this file.

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013, Digium, Inc.
 *
 * David M. Lee, II <dlee@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 Stored file operations for Stasis
 *
 * \author David M. Lee, II <dlee@digium.com>
 */
 
#include "asterisk.h"
 
#include "asterisk/astobj2.h"
#include "asterisk/paths.h"
#include "asterisk/stasis_app_recording.h"
 
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
 
struct stasis_app_stored_recording {
    AST_DECLARE_STRING_FIELDS(
        AST_STRING_FIELD(name); /*!< Recording's name */
        AST_STRING_FIELD(file); /*!< Absolute filename, without extension; for use with streamfile */
        AST_STRING_FIELD(file_with_ext);    /*!< Absolute filename, with extension; for use with everything else */
        );
 
    const char *format; /*!< Format name (i.e. filename extension) */
};
 
static void stored_recording_dtor(void *obj)
{
    struct stasis_app_stored_recording *recording = obj;
 
    ast_string_field_free_memory(recording);
}
 
const char *stasis_app_stored_recording_get_file(
    struct stasis_app_stored_recording *recording)
{
    if (!recording) {
        return NULL;
    }
    return recording->file;
}
 
const char *stasis_app_stored_recording_get_filename(
    struct stasis_app_stored_recording *recording)
{
    if (!recording) {
        return NULL;
    }
    return recording->file_with_ext;
}
 
const char *stasis_app_stored_recording_get_extension(
    struct stasis_app_stored_recording *recording)
{
    if (!recording) {
        return NULL;
    }
    return recording->format;
}
 
/*!
 * \brief Split a path into directory and file, resolving canonical directory.
 *
 * The path is resolved relative to the recording directory. Both dir and file
 * are allocated strings, which you must ast_free().
 *
 * \param path Path to split.
 * \param[out] dir Output parameter for directory portion.
 * \param[out] file Output parameter for the file portion.
 * \return 0 on success.
 * \return Non-zero on error.
 */
static int split_path(const char *path, char **dir, char **file)
{
    RAII_VAR(char *, relative_dir, NULL, ast_free);
    RAII_VAR(char *, absolute_dir, NULL, ast_free);
    RAII_VAR(char *, real_dir, NULL, ast_std_free);
    char *last_slash;
    const char *file_portion;
 
    relative_dir = ast_strdup(path);
    if (!relative_dir) {
        return -1;
    }
 
    last_slash = strrchr(relative_dir, '/');
    if (last_slash) {
        *last_slash = '\0';
        file_portion = last_slash + 1;
        ast_asprintf(&absolute_dir, "%s/%s",
            ast_config_AST_RECORDING_DIR, relative_dir);
    } else {
        /* There is no directory portion */
        file_portion = path;
        *relative_dir = '\0';
        absolute_dir = ast_strdup(ast_config_AST_RECORDING_DIR);
    }
    if (!absolute_dir) {
        return -1;
    }
 
    real_dir = realpath(absolute_dir, NULL);
    if (!real_dir) {
        return -1;
    }
 
    *dir = ast_strdup(real_dir); /* Dupe so we can ast_free() */
    *file = ast_strdup(file_portion);
    return (*dir && *file) ? 0 : -1;
}
 
struct match_recording_data {
    const char *file;
    size_t length;
    char *file_with_ext;
};
 
static int is_recording(const char *filename)
{
    const char *ext = strrchr(filename, '.');
 
    if (!ext) {
        /* No file extension; not us */
        return 0;
    }
    ++ext;
 
    if (!ast_get_format_for_file_ext(ext)) {
        ast_debug(5, "Recording %s: unrecognized format %s\n",
            filename, ext);
        /* Keep looking */
        return 0;
    }
 
    /* Return the index to the .ext */
    return ext - filename - 1;
}
 
static int handle_find_recording(const char *dir_name, const char *filename, void *obj)
{
    struct match_recording_data *data = obj;
    int num;
 
    /* If not a recording or the names do not match the keep searching */
    if (!(num = is_recording(filename))
       || data->length != num
       || strncmp(data->file, filename, num)) {
        return 0;
    }
 
    if (ast_asprintf(&data->file_with_ext, "%s/%s", dir_name, filename) < 0) {
        return -1;
    }
 
    return 1;
}
 
/*!
 * \brief Finds a recording in the given directory.
 *
 * This function searches for a file with the given file name, with a registered
 * format that matches its extension.
 *
 * \param dir_name Directory to search (absolute path).
 * \param file File name, without extension.
 * \return Absolute path of the recording file.
 * \retval NULL if recording is not found.
 */
static char *find_recording(const char *dir_name, const char *file)
{
    struct match_recording_data data = {
        .file = file,
        .length = strlen(file),
        .file_with_ext = NULL
    };
 
    ast_file_read_dir(dir_name, handle_find_recording, &data);
 
    /* Note, string potentially allocated in handle_file_recording */
    return data.file_with_ext;
}
 
/*!
 * \brief Allocate a recording object.
 */
static struct stasis_app_stored_recording *recording_alloc(void)
{
    RAII_VAR(struct stasis_app_stored_recording *, recording, NULL,
        ao2_cleanup);
    int res;
 
    recording = ao2_alloc(sizeof(*recording), stored_recording_dtor);
    if (!recording) {
        return NULL;
    }
 
    res = ast_string_field_init(recording, 255);
    if (res != 0) {
        return NULL;
    }
 
    ao2_ref(recording, +1);
    return recording;
}
 
static int recording_sort(const void *obj_left, const void *obj_right, int flags)
{
    const struct stasis_app_stored_recording *object_left = obj_left;
    const struct stasis_app_stored_recording *object_right = obj_right;
    const char *right_key = obj_right;
    int cmp;
 
    switch (flags & (OBJ_POINTER | OBJ_KEY | OBJ_PARTIAL_KEY)) {
    case OBJ_POINTER:
        right_key = object_right->name;
        /* Fall through */
    case OBJ_KEY:
        cmp = strcmp(object_left->name, right_key);
        break;
    case OBJ_PARTIAL_KEY:
        /*
         * We could also use a partial key struct containing a length
         * so strlen() does not get called for every comparison instead.
         */
        cmp = strncmp(object_left->name, right_key, strlen(right_key));
        break;
    default:
        /* Sort can only work on something with a full or partial key. */
        ast_assert(0);
        cmp = 0;
        break;
    }
    return cmp;
}
 
static int handle_scan_file(const char *dir_name, const char *filename, void *obj)
{
    struct ao2_container *recordings = obj;
    struct stasis_app_stored_recording *recording;
    char *dot, *filepath;
 
    /* Skip if it is not a recording */
    if (!is_recording(filename)) {
        return 0;
    }
 
    if (ast_asprintf(&filepath, "%s/%s", dir_name, filename) < 0) {
        return -1;
    }
 
    recording = recording_alloc();
    if (!recording) {
        ast_free(filepath);
        return -1;
    }
 
    ast_string_field_set(recording, file_with_ext, filepath);
    /* Build file and format from full path */
    ast_string_field_set(recording, file, filepath);
 
    ast_free(filepath);
 
    dot = strrchr(recording->file, '.');
    *dot = '\0';
    recording->format = dot + 1;
 
    /* Removed the recording dir from the file for the name. */
    ast_string_field_set(recording, name,
        recording->file + strlen(ast_config_AST_RECORDING_DIR) + 1);
 
    /* Add it to the recordings container */
    ao2_link(recordings, recording);
    ao2_ref(recording, -1);
 
    return 0;
}
 
struct ao2_container *stasis_app_stored_recording_find_all(void)
{
    struct ao2_container *recordings;
    int res;
 
    recordings = ao2_container_alloc_rbtree(AO2_ALLOC_OPT_LOCK_NOLOCK,
        AO2_CONTAINER_ALLOC_OPT_DUPS_REPLACE, recording_sort, NULL);
    if (!recordings) {
        return NULL;
    }
 
    res = ast_file_read_dirs(ast_config_AST_RECORDING_DIR,
                 handle_scan_file, recordings, -1);
    if (res) {
        ao2_ref(recordings, -1);
        return NULL;
    }
 
    return recordings;
}
 
struct stasis_app_stored_recording *stasis_app_stored_recording_find_by_name(
    const char *name)
{
    RAII_VAR(struct stasis_app_stored_recording *, recording, NULL,
        ao2_cleanup);
    RAII_VAR(char *, dir, NULL, ast_free);
    RAII_VAR(char *, file, NULL, ast_free);
    RAII_VAR(char *, file_with_ext, NULL, ast_free);
    int res;
    struct stat file_stat;
    int prefix_len = strlen(ast_config_AST_RECORDING_DIR);
 
    errno = 0;
 
    if (!name) {
        errno = EINVAL;
        return NULL;
    }
 
    recording = recording_alloc();
    if (!recording) {
        return NULL;
    }
 
    res = split_path(name, &dir, &file);
    if (res != 0) {
        return NULL;
    }
    ast_string_field_build(recording, file, "%s/%s", dir, file);
 
    if (!ast_begins_with(dir, ast_config_AST_RECORDING_DIR)) {
        /* It's possible that one or more component of the recording path is
         * a symbolic link, this would prevent dir from ever matching. */
        char *real_basedir = realpath(ast_config_AST_RECORDING_DIR, NULL);
 
        if (!real_basedir || !ast_begins_with(dir, real_basedir)) {
            /* Attempt to escape the recording directory */
            ast_log(LOG_WARNING, "Attempt to access invalid recording directory %s\n",
                dir);
            ast_std_free(real_basedir);
            errno = EACCES;
 
            return NULL;
        }
 
        prefix_len = strlen(real_basedir);
        ast_std_free(real_basedir);
    }
 
    /* The actual name of the recording is file with the config dir
     * prefix removed.
     */
    ast_string_field_set(recording, name, recording->file + prefix_len + 1);
 
    file_with_ext = find_recording(dir, file);
    if (!file_with_ext) {
        return NULL;
    }
    ast_string_field_set(recording, file_with_ext, file_with_ext);
    recording->format = strrchr(recording->file_with_ext, '.');
    if (!recording->format) {
        return NULL;
    }
    ++(recording->format);
 
    res = stat(file_with_ext, &file_stat);
    if (res != 0) {
        return NULL;
    }
 
    if (!S_ISREG(file_stat.st_mode)) {
        /* Let's not play if it's not a regular file */
        errno = EACCES;
        return NULL;
    }
 
    ao2_ref(recording, +1);
    return recording;
}
 
int stasis_app_stored_recording_copy(struct stasis_app_stored_recording *src_recording, const char *dst,
    struct stasis_app_stored_recording **dst_recording)
{
    RAII_VAR(char *, full_path, NULL, ast_free);
    char *dst_file = ast_strdupa(dst);
    char *format;
    char *last_slash;
    int res;
 
    /* Drop the extension if specified, core will do this for us */
    format = strrchr(dst_file, '.');
    if (format) {
        *format = '\0';
    }
 
    /* See if any intermediary directories need to be made */
    last_slash = strrchr(dst_file, '/');
    if (last_slash) {
        RAII_VAR(char *, tmp_path, NULL, ast_free);
 
        *last_slash = '\0';
        if (ast_asprintf(&tmp_path, "%s/%s", ast_config_AST_RECORDING_DIR, dst_file) < 0) {
            return -1;
        }
        if (ast_safe_mkdir(ast_config_AST_RECORDING_DIR,
                tmp_path, 0777) != 0) {
            /* errno set by ast_mkdir */
            return -1;
        }
        *last_slash = '/';
        if (ast_asprintf(&full_path, "%s/%s", ast_config_AST_RECORDING_DIR, dst_file) < 0) {
            return -1;
        }
    } else {
        /* There is no directory portion */
        if (ast_asprintf(&full_path, "%s/%s", ast_config_AST_RECORDING_DIR, dst_file) < 0) {
            return -1;
        }
    }
 
    ast_verb(4, "Copying recording %s to %s (format %s)\n", src_recording->file,
        full_path, src_recording->format);
    res = ast_filecopy(src_recording->file, full_path, src_recording->format);
    if (!res) {
        *dst_recording = stasis_app_stored_recording_find_by_name(dst_file);
    }
 
    return res;
}
 
int stasis_app_stored_recording_delete(
    struct stasis_app_stored_recording *recording)
{
    /* Path was validated when the recording object was created */
    return unlink(recording->file_with_ext);
}
 
struct ast_json *stasis_app_stored_recording_to_json(
    struct stasis_app_stored_recording *recording)
{
    if (!recording) {
        return NULL;
    }
 
    return ast_json_pack("{ s: s, s: s }",
        "name", recording->name,
        "format", recording->format);
}