session_file.c

Go to the documentation of this file.

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2013 Bert Vermeulen <bert@biot.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <config.h>
#include <string.h>
#include <stdlib.h>
#include <zip.h>
#include <errno.h>
#include <glib.h>
#include <glib/gstdio.h>
#include <libsigrok/libsigrok.h>
#include "libsigrok-internal.h"

/** @cond PRIVATE */
#define LOG_PREFIX "session-file"
/** @endcond */

/**
 * @file
 *
 * Loading and saving libsigrok session files.
 */

/**
 * @addtogroup grp_session
 *
 * @{
 */

extern SR_PRIV struct sr_dev_driver session_driver;
static int session_driver_initialized = 0;

#if !HAVE_ZIP_DISCARD
/* Replacement for zip_discard() if it isn't available.
 */
SR_PRIV void sr_zip_discard(struct zip *archive)
{
        if (zip_unchange_all(archive) < 0 || zip_close(archive) < 0)
                sr_err("Failed to discard ZIP archive: %s", zip_strerror(archive));
}
#endif

/** Read metadata entries from a session archive.
 * @param[in] archive An open ZIP archive.
 * @param[in] entry Stat buffer filled in for the metadata archive member.
 * @return A new key/value store containing the session metadata.
 */
SR_PRIV GKeyFile *sr_sessionfile_read_metadata(struct zip *archive,
                        const struct zip_stat *entry)
{
        GKeyFile *keyfile;
        GError *error;
        struct zip_file *zf;
        char *metabuf;
        int metalen;

        if (entry->size > G_MAXINT || !(metabuf = g_try_malloc(entry->size))) {
                sr_err("Metadata buffer allocation failed.");
                return NULL;
        }
        zf = zip_fopen_index(archive, entry->index, 0);
        if (!zf) {
                sr_err("Failed to open metadata: %s", zip_strerror(archive));
                g_free(metabuf);
                return NULL;
        }
        metalen = zip_fread(zf, metabuf, entry->size);
        if (metalen < 0) {
                sr_err("Failed to read metadata: %s", zip_file_strerror(zf));
                zip_fclose(zf);
                g_free(metabuf);
                return NULL;
        }
        zip_fclose(zf);

        keyfile = g_key_file_new();
        error = NULL;
        g_key_file_load_from_data(keyfile, metabuf, metalen,
                        G_KEY_FILE_NONE, &error);
        g_free(metabuf);

        if (error) {
                sr_err("Failed to parse metadata: %s", error->message);
                g_error_free(error);
                g_key_file_free(keyfile);
                return NULL;
        }
        return keyfile;
}

/** @private */
SR_PRIV int sr_sessionfile_check(const char *filename)
{
        struct zip *archive;
        struct zip_file *zf;
        struct zip_stat zs;
        uint64_t version;
        int ret;
        char s[11];

        if (!filename)
                return SR_ERR_ARG;

        if (!g_file_test(filename, G_FILE_TEST_IS_REGULAR)) {
                sr_err("Not a regular file: %s.", filename);
                return SR_ERR;
        }

        if (!(archive = zip_open(filename, 0, NULL)))
                /* No logging: this can be used just to check if it's
                 * a sigrok session file or not. */
                return SR_ERR;

        /* check "version" */
        if (!(zf = zip_fopen(archive, "version", 0))) {
                sr_dbg("Not a sigrok session file: no version found.");
                zip_discard(archive);
                return SR_ERR;
        }
        ret = zip_fread(zf, s, sizeof(s) - 1);
        if (ret < 0) {
                sr_err("Failed to read version file: %s",
                        zip_file_strerror(zf));
                zip_fclose(zf);
                zip_discard(archive);
                return SR_ERR;
        }
        zip_fclose(zf);
        s[ret] = '\0';
        version = g_ascii_strtoull(s, NULL, 10);
        if (version == 0 || version > 2) {
                sr_dbg("Cannot handle sigrok session file version %" PRIu64 ".",
                        version);
                zip_discard(archive);
                return SR_ERR;
        }
        sr_spew("Detected sigrok session file version %" PRIu64 ".", version);

        /* read "metadata" */
        if (zip_stat(archive, "metadata", 0, &zs) < 0) {
                sr_dbg("Not a valid sigrok session file.");
                zip_discard(archive);
                return SR_ERR;
        }
        zip_discard(archive);

        return SR_OK;
}

/**
 * Load the session from the specified filename.
 *
 * @param ctx The context in which to load the session.
 * @param filename The name of the session file to load.
 * @param session The session to load the file into.
 *
 * @retval SR_OK Success
 * @retval SR_ERR_MALLOC Memory allocation error
 * @retval SR_ERR_DATA Malformed session file
 * @retval SR_ERR This is not a session file
 */
SR_API int sr_session_load(struct sr_context *ctx, const char *filename,
                struct sr_session **session)
{
        GKeyFile *kf;
        GError *error;
        struct zip *archive;
        struct zip_stat zs;
        struct sr_dev_inst *sdi;
        struct sr_channel *ch;
        int ret, i, j;
        uint64_t tmp_u64;
        int total_channels, k;
        int unitsize;
        char **sections, **keys, *val;
        char channelname[SR_MAX_CHANNELNAME_LEN + 1];

        if ((ret = sr_sessionfile_check(filename)) != SR_OK)
                return ret;

        if (!(archive = zip_open(filename, 0, NULL)))
                return SR_ERR;

        if (zip_stat(archive, "metadata", 0, &zs) < 0) {
                zip_discard(archive);
                return SR_ERR;
        }
        kf = sr_sessionfile_read_metadata(archive, &zs);
        zip_discard(archive);
        if (!kf)
                return SR_ERR_DATA;

        if ((ret = sr_session_new(ctx, session)) != SR_OK) {
                g_key_file_free(kf);
                return ret;
        }

        error = NULL;
        ret = SR_OK;
        sections = g_key_file_get_groups(kf, NULL);
        for (i = 0; sections[i] && ret == SR_OK; i++) {
                if (!strcmp(sections[i], "global"))
                        /* nothing really interesting in here yet */
                        continue;
                if (!strncmp(sections[i], "device ", 7)) {
                        /* device section */
                        sdi = NULL;
                        keys = g_key_file_get_keys(kf, sections[i], NULL, NULL);
                        for (j = 0; keys[j]; j++) {
                                if (!strcmp(keys[j], "capturefile")) {
                                        val = g_key_file_get_string(kf, sections[i],
                                                        keys[j], &error);
                                        if (!val) {
                                                ret = SR_ERR_DATA;
                                                break;
                                        }
                                        sdi = g_malloc0(sizeof(struct sr_dev_inst));
                                        sdi->driver = &session_driver;
                                        sdi->status = SR_ST_ACTIVE;
                                        if (!session_driver_initialized) {
                                                /* first device, init the driver */
                                                session_driver_initialized = 1;
                                                sdi->driver->init(sdi->driver, NULL);
                                        }
                                        sr_dev_open(sdi);
                                        sr_session_dev_add(*session, sdi);
                                        (*session)->owned_devs = g_slist_append(
                                                        (*session)->owned_devs, sdi);
                                        sr_config_set(sdi, NULL, SR_CONF_SESSIONFILE,
                                                        g_variant_new_string(filename));
                                        sr_config_set(sdi, NULL, SR_CONF_CAPTUREFILE,
                                                        g_variant_new_string(val));
                                        g_free(val);
                                } else if (!strcmp(keys[j], "samplerate")) {
                                        val = g_key_file_get_string(kf, sections[i],
                                                        keys[j], &error);
                                        if (!sdi || !val || sr_parse_sizestring(val,
                                                                &tmp_u64) != SR_OK) {
                                                g_free(val);
                                                ret = SR_ERR_DATA;
                                                break;
                                        }
                                        g_free(val);
                                        sr_config_set(sdi, NULL, SR_CONF_SAMPLERATE,
                                                        g_variant_new_uint64(tmp_u64));
                                } else if (!strcmp(keys[j], "unitsize")) {
                                        unitsize = g_key_file_get_integer(kf, sections[i],
                                                        keys[j], &error);
                                        if (!sdi || unitsize <= 0 || error) {
                                                ret = SR_ERR_DATA;
                                                break;
                                        }
                                        sr_config_set(sdi, NULL, SR_CONF_CAPTURE_UNITSIZE,
                                                        g_variant_new_uint64(unitsize));
                                } else if (!strcmp(keys[j], "total probes")) {
                                        total_channels = g_key_file_get_integer(kf,
                                                        sections[i], keys[j], &error);
                                        if (!sdi || total_channels < 0 || error) {
                                                ret = SR_ERR_DATA;
                                                break;
                                        }
                                        sr_config_set(sdi, NULL, SR_CONF_NUM_LOGIC_CHANNELS,
                                                        g_variant_new_int32(total_channels));
                                        for (k = 0; k < total_channels; k++) {
                                                g_snprintf(channelname, sizeof(channelname),
                                                                "%d", k);
                                                sr_channel_new(sdi, k, SR_CHANNEL_LOGIC,
                                                                FALSE, channelname);
                                        }
                                } else if (!strncmp(keys[j], "probe", 5)) {
                                        tmp_u64 = g_ascii_strtoull(keys[j] + 5, NULL, 10);
                                        if (!sdi || tmp_u64 == 0 || tmp_u64 > G_MAXINT) {
                                                ret = SR_ERR_DATA;
                                                break;
                                        }
                                        ch = g_slist_nth_data(sdi->channels, tmp_u64 - 1);
                                        if (!ch) {
                                                ret = SR_ERR_DATA;
                                                break;
                                        }
                                        val = g_key_file_get_string(kf, sections[i],
                                                        keys[j], &error);
                                        if (!val) {
                                                ret = SR_ERR_DATA;
                                                break;
                                        }
                                        /* sr_session_save() */
                                        sr_dev_channel_name_set(ch, val);
                                        g_free(val);
                                        sr_dev_channel_enable(ch, TRUE);
                                }
                        }
                        g_strfreev(keys);
                }
        }
        g_strfreev(sections);
        g_key_file_free(kf);

        if (error) {
                sr_err("Failed to parse metadata: %s", error->message);
                g_error_free(error);
        }
        return ret;
}

/** @} */