loglevel adjustments.

[paraslash.git] / afs.c

/*
 * Copyright (C) 2007 Andre Noll <maan@systemlinux.org>
 *
 * Licensed under the GPL v2. For licencing details see COPYING.
 */

/** \file afs.c Paraslash's audio file selector. */

#include "server.cmdline.h"
#include "para.h"
#include "afh.h"
#include "server.h"
#include "error.h"
#include <dirent.h> /* readdir() */
#include <sys/mman.h>
#include <sys/time.h>
#include "net.h"
#include "afs.h"
#include "ipc.h"
#include "string.h"
#include "list.h"
#include "sched.h"
#include "signal.h"
#include "fd.h"

/** The osl tables used by afs. \sa blob.c. */
enum afs_table_num {
        /** Contains audio file information. See aft.c. */
        TBLNUM_AUDIO_FILES,
        /** The table for the paraslash attributes. See attribute.c. */
        TBLNUM_ATTRIBUTES,
        /**
         * Paraslash's scoring system is based on Gaussian normal
         * distributions, and the relevant data is stored in the rbtrees of an
         * osl table containing only volatile columns.  See score.c for
         * details.
         */
        TBLNUM_SCORES,
        /**
         * A standard blob table containing the mood definitions. For details
         * see mood.c.
         */
        TBLNUM_MOODS,
        /** A blob table containing lyrics on a per-song basis. */
        TBLNUM_LYRICS,
        /** Another blob table for images (for example album cover art). */
        TBLNUM_IMAGES,
        /** Yet another blob table for storing standard playlists. */
        TBLNUM_PLAYLIST,
        /** How many tables are in use? */
        NUM_AFS_TABLES
};

static struct table_info afs_tables[NUM_AFS_TABLES];

struct command_task {
        /** The file descriptor for the local socket. */
        int fd;
        /**
         * Value sent by the command handlers to identify themselves as
         * children of the running para_server.
         */
        uint32_t cookie;
        /** The associated task structure. */
        struct task task;
};

/**
 * A random number used to "authenticate" the connection.
 *
 * para_server picks this number by random before forking the afs process.  The
 * command handlers write this number together with the id of the shared memory
 * area containing the query. This way, a malicious local user has to know this
 * number to be able to cause the afs process to crash by sending fake queries.
 */
extern uint32_t afs_socket_cookie;

/**
 * Struct to let command handlers execute a callback in afs context.
 *
 * Commands that need to change the state of afs can't change the relevant data
 * structures directly because commands are executed in a child process, i.e.
 * they get their own virtual address space.
 *
 * This structure is used by \p send_callback_request() (executed from handler
 * context) in order to let the afs process call the specified function. An
 * instance of that structure is written to a shared memory area together with
 * the arguments to the callback function. The identifier of the shared memory
 * area is written to the command socket.
 *
 * The afs process accepts connections on the command socket and reads the
 * shared memory id, attaches the corresponing area, calls the given handler to
 * perform the desired action and to optionally compute a result.
 *
 * The result and a \p callback_result structure is then written to another
 * shared memory area. The identifier for that area is written to the handler's
 * command socket, so that the handler process can read the id, attach the
 * shared memory area and use the result.
 *
 * \sa struct callback_result.
 */
struct callback_query {
        /** The function to be called. */
        callback_function *handler;
        /** The number of bytes of the query */
        size_t query_size;
};

/**
 * Structure embedded in the result of a callback.
 *
 * If the callback produced a result, an instance of that structure is embeeded
 * into the shared memory area holding the result, mainly to let the command
 * handler know the size of the result.
 *
 * \sa struct callback_query.
 */
struct callback_result {
        /** The number of bytes of the result. */
        size_t result_size;
};

/**
 * Ask the parent process to call a given function.
 *
 * \param f The function to be called.
 * \param query Pointer to arbitrary data for the callback.
 * \param result Callback result will be stored here.
 *
 * This function creates a shared memory area, copies the buffer pointed to by
 * \a buf to that area and notifies the afs process that \a f should be
 * called ASAP.
 *
 * \return Negative, on errors, the return value of the callback function
 * otherwise.
 *
 * \sa send_option_arg_callback_request(), send_standard_callback_request().
 */
int send_callback_request(callback_function *f, struct osl_object *query,
                struct osl_object *result)
{
        struct callback_query *cq;
        struct callback_result *cr;
        int ret, fd = -1, query_shmid, result_shmid;
        void *query_shm, *result_shm;
        char buf[sizeof(afs_socket_cookie) + sizeof(int)];
//      char *tmpsocket_name;
        struct sockaddr_un unix_addr;

        assert(query->data && query->size);
        ret = shm_new(query->size + sizeof(*cq));
        if (ret < 0)
                return ret;
        query_shmid = ret;
        ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
        if (ret < 0)
                goto out;
        cq = query_shm;
        cq->handler = f;
        cq->query_size = query->size;

        memcpy(query_shm + sizeof(*cq), query->data, query->size);
        ret = shm_detach(query_shm);
        if (ret < 0)
                goto out;

        *(uint32_t *) buf = afs_socket_cookie;
        *(int *) (buf + sizeof(afs_socket_cookie)) = query_shmid;

        ret = get_stream_socket(PF_UNIX);
        if (ret < 0)
                goto out;
        fd = ret;
        ret = init_unix_addr(&unix_addr, conf.afs_socket_arg);
        if (ret < 0)
                goto out;
        ret = -E_CONNECT;
        if (connect(fd, (struct sockaddr *)&unix_addr, sizeof(unix_addr)) < 0) /* FIXME: Use para_connect() */
                goto out;
        ret = send_bin_buffer(fd, buf, sizeof(buf));
        if (ret < 0)
                goto out;
        ret = recv_bin_buffer(fd, buf, sizeof(buf));
        if (ret < 0)
                goto out;
        if (ret != sizeof(int)) {
                ret = -E_RECV;
                goto out;
        }
        ret = *(int *) buf;
        if (ret <= 0)
                goto out;
        result_shmid = ret;
        ret = shm_attach(result_shmid, ATTACH_RO, &result_shm);
        if (ret >= 0) {
                assert(result);
                cr = result_shm;
                result->size = cr->result_size;
                result->data = para_malloc(result->size);
                memcpy(result->data, result_shm + sizeof(*cr), result->size);
                ret = shm_detach(result_shm);
                if (ret < 0)
                        PARA_ERROR_LOG("can not detach result\n");
        } else
                PARA_ERROR_LOG("attach result failed: %d\n", ret);
        if (shm_destroy(result_shmid) < 0)
                PARA_ERROR_LOG("destroy result failed\n");
        ret = 1;
out:
        if (shm_destroy(query_shmid) < 0)
                PARA_ERROR_LOG("%s\n", "shm destroy error");
        if (fd >= 0)
                close(fd);
//      PARA_DEBUG_LOG("callback_ret: %d\n", ret);
        return ret;
}

/**
 * Send a callback request passing an options structure and an argument vector.
 *
 * \param options pointer to an arbitrary data structure.
 * \param argc Argument count.
 * \param argv Standard argument vector.
 * \param f The callback function.
 * \param result The result of the query is stored here.
 *
 * Some commands have a couple of options that are parsed in child context for
 * syntactic correctness and are stored in a special options structure for that
 * command. This function allows to pass such a structure together with a list
 * of further arguments (often a list of audio files) to the parent process.
 *
 * \sa send_standard_callback_request(), send_callback_request().
 */
int send_option_arg_callback_request(struct osl_object *options,
                int argc,  char * const * const argv, callback_function *f,
                struct osl_object *result)
{
        char *p;
        int i, ret;
        struct osl_object query = {.size = options? options->size : 0};

        for (i = 0; i < argc; i++)
                query.size += strlen(argv[i]) + 1;
        query.data = para_malloc(query.size);
        p = query.data;
        if (options) {
                memcpy(query.data, options->data, options->size);
                p += options->size;
        }
        for (i = 0; i < argc; i++) {
                strcpy(p, argv[i]); /* OK */
                p += strlen(argv[i]) + 1;
        }
        ret = send_callback_request(f, &query, result);
        free(query.data);
        return ret;
}

/**
 * Send a callback request with an argument vector only.
 *
 * \param argc The same meaning as in send_option_arg_callback_request().
 * \param argv The same meaning as in send_option_arg_callback_request().
 * \param f The same meaning as in send_option_arg_callback_request().
 * \param result The same meaning as in send_option_arg_callback_request().
 *
 * This is similar to send_option_arg_callback_request(), but no options buffer
 * is passed to the parent process.
 *
 * \return The return value of the underlying call to
 * send_option_arg_callback_request().
 */
int send_standard_callback_request(int argc,  char * const * const argv,
                callback_function *f, struct osl_object *result)
{
        return send_option_arg_callback_request(NULL, argc, argv, f, result);
}

/**
 * Compare two osl objects of string type.
 *
 * \param obj1 Pointer to the first object.
 * \param obj2 Pointer to the second object.
 *
 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
 * are taken into account.
 *
 * \return It returns an integer less than, equal to, or greater than zero if
 * \a obj1 is found, respectively, to be less than, to match, or be greater than
 * obj2.
 *
 * \sa strcmp(3), strncmp(3), osl_compare_func.
 */
int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
{
        const char *str1 = (const char *)obj1->data;
        const char *str2 = (const char *)obj2->data;
        return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
}

/**
 * A wrapper for strtol(3).
 *
 * \param str The string to be converted to a long integer.
 * \param result The converted value is stored here.
 *
 * \return Positive on success, -E_ATOL on errors.
 *
 * \sa strtol(3), atoi(3).
 */
int para_atol(const char *str, long *result)
{
        char *endptr;
        long val;
        int ret, base = 10;

        errno = 0; /* To distinguish success/failure after call */
        val = strtol(str, &endptr, base);
        ret = -E_ATOL;
        if (errno == ERANGE && (val == LONG_MAX || val == LONG_MIN))
                goto out; /* overflow */
        if (errno != 0 && val == 0)
                goto out; /* other error */
        if (endptr == str)
                goto out; /* No digits were found */
        if (*endptr != '\0')
                goto out; /* Further characters after number */
        *result = val;
        ret = 1;
out:
        return ret;
}


/*
 * write input from fd to dynamically allocated char array,
 * but maximal max_size byte. Return size.
 */
static int fd2buf(int fd, char **buf, int max_size)
{
        const size_t chunk_size = 1024;
        size_t size = 2048;
        char *p;
        int ret;

        *buf = para_malloc(size * sizeof(char));
        p = *buf;
        while ((ret = read(fd, p, chunk_size)) > 0) {
                p += ret;
                if ((p - *buf) + chunk_size >= size) {
                        char *tmp;

                        size *= 2;
                        if (size > max_size) {
                                ret = -E_INPUT_TOO_LARGE;
                                goto out;
                        }
                        tmp = para_realloc(*buf, size);
                        p = (p - *buf) + tmp;
                        *buf = tmp;
                }
        }
        if (ret < 0) {
                ret = -E_READ;
                goto out;
        }
        ret = p - *buf;
out:
        if (ret < 0 && *buf)
                free(*buf);
        return ret;
}

/**
 * Read from stdin, and send the result to the parent process.
 *
 * \param arg_obj Pointer to the arguments to \a f.
 * \param f The callback function.
 * \param max_len Don't read more than that many bytes from stdin.
 * \param result The result of the query is stored here.
 *
 * This function is used by commands that wish to let para_server store
 * arbitrary data specified by the user (for instance the add_blob family of
 * commands). First, at most \a max_len bytes are read from stdin, the result
 * is concatenated with the buffer given by \a arg_obj, and the combined buffer
 * is made available to the parent process via shared memory.
 *
 * \return Negative on errors, the return value of the underlying call to
 * send_callback_request() otherwise.
 */
int stdin_command(struct osl_object *arg_obj, callback_function *f,
                unsigned max_len, struct osl_object *result)
{
        char *stdin_buf;
        size_t stdin_len;
        struct osl_object query;
        int ret = fd2buf(STDIN_FILENO, &stdin_buf, max_len);

        if (ret < 0)
                return ret;
        stdin_len = ret;
        query.size = arg_obj->size + stdin_len;
        query.data = para_malloc(query.size);
        memcpy(query.data, arg_obj->data, arg_obj->size);
        memcpy((char *)query.data + arg_obj->size, stdin_buf, stdin_len);
        free(stdin_buf);
        ret = send_callback_request(f, &query, result);
        free(query.data);
        return ret;
}

/**
 * Open the audio file with highest score.
 *
 * \param afd Audio file data is returned here.
 *
 * This stores all information for streaming the "best" audio file
 * in the \a afd structure.
 *
 * \return Positive on success, negative on errors.
 *
 * \sa close_audio_file(), open_and_update_audio_file().
 */
int open_next_audio_file(struct audio_file_data *afd)
{
        struct osl_row *aft_row;
        int ret;
        for (;;) {
                ret = score_get_best(&aft_row, &afd->score);
                if (ret < 0)
                        return ret;
                ret = open_and_update_audio_file(aft_row, afd);
                if (ret >= 0)
                        return ret;
        }
}

/**
 * Free all resources which were allocated by open_next_audio_file().
 *
 * \param afd The structure previously filled in by open_next_audio_file().
 *
 * \return The return value of the underlying call to para_munmap().
 *
 * \sa open_next_audio_file().
 */
int close_audio_file(struct audio_file_data *afd)
{
        free(afd->afhi.chunk_table);
        return para_munmap(afd->map.data, afd->map.size);
}

#if 0
static void play_loop(enum play_mode current_play_mode)
{
        int i, ret;
        struct audio_file_data afd;

        afd.current_play_mode = current_play_mode;
        for (i = 0; i < 0; i++) {
                ret = open_next_audio_file(&afd);
                if (ret < 0) {
                        PARA_ERROR_LOG("failed to open next audio file: %d\n", ret);
                        return;
                }
                PARA_NOTICE_LOG("next audio file: %s, score: %li\n", afd.path, afd.score);
                sleep(1);
                close_audio_file(&afd);
        }
}
#endif


static enum play_mode init_admissible_files(void)
{
        int ret;
        char *given_mood, *given_playlist;

        given_mood = "mood_that_was_given_at_the_command_line";
        given_playlist = "given_playlist";

        if (given_mood) {
                ret = mood_open(given_mood);
                if (ret >= 0) {
                        if (given_playlist)
                                PARA_WARNING_LOG("ignoring playlist %s\n",
                                        given_playlist);
                        return PLAY_MODE_MOOD;
                }
        }
        if (given_playlist) {
                ret = playlist_open(given_playlist);
                if (ret >= 0)
                        return PLAY_MODE_PLAYLIST;
        }
        ret = mood_open(NULL); /* open first available mood */
        if (ret >= 0)
                return PLAY_MODE_MOOD;
        mood_open(""); /* open dummy mood, always successful */
        return PLAY_MODE_MOOD;
}

static int setup_command_socket_or_die(void)
{
        int ret;
        char *socket_name = conf.afs_socket_arg;
        struct sockaddr_un unix_addr;

        unlink(socket_name);
        ret = create_local_socket(socket_name, &unix_addr,
                S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
        if (ret < 0) {
                PARA_EMERG_LOG("%s: %s\n", PARA_STRERROR(-ret), socket_name);
                exit(EXIT_FAILURE);
        }
        if (listen(ret , 5) < 0) {
                PARA_EMERG_LOG("%s", "can not listen on socket\n");
                exit(EXIT_FAILURE);
        }
        PARA_INFO_LOG("listening on command socket %s (fd %d)\n", socket_name,
                ret);
        return ret;
}

static int server_socket;
static struct command_task command_task_struct;
static struct signal_task signal_task_struct;

static void unregister_tasks(void)
{
        unregister_task(&command_task_struct.task);
        unregister_task(&signal_task_struct.task);
}

static void close_afs_tables(enum osl_close_flags flags)
{
        PARA_NOTICE_LOG("closing afs_tables\n");
        score_shutdown(flags);
        attribute_shutdown(flags);
        mood_close();
        playlist_close();
        moods_shutdown(flags);
        playlists_shutdown(flags);
        lyrics_shutdown(flags);
        images_shutdown(flags);
        aft_shutdown(flags);
}

static void signal_pre_select(struct sched *s, struct task *t)
{
        struct signal_task *st = t->private_data;
        t->ret = 1;
        para_fd_set(st->fd, &s->rfds, &s->max_fileno);
}

static void signal_post_select(struct sched *s, struct task *t)
{
        struct signal_task *st = t->private_data;
        t->ret = 1;
        if (!FD_ISSET(st->fd, &s->rfds))
                return;
        st->signum = para_next_signal();
        PARA_NOTICE_LOG("caught signal %d\n", st->signum);
        t->ret = 1;
        if (st->signum == SIGUSR1)
                return; /* ignore SIGUSR1 */
        t->ret = -E_SIGNAL_CAUGHT;
        unregister_tasks();
}

static void register_signal_task(void)
{
        struct signal_task *st = &signal_task_struct;
        st->fd = para_signal_init();
        PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
        para_install_sighandler(SIGINT);
        para_install_sighandler(SIGTERM);
        para_install_sighandler(SIGPIPE);

        st->task.pre_select = signal_pre_select;
        st->task.post_select = signal_post_select;
        st->task.private_data = st;
        sprintf(st->task.status, "signal task");
        register_task(&st->task);
}

static void command_pre_select(struct sched *s, struct task *t)
{
        struct command_task *ct = t->private_data;
        t->ret = 1;
        para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
}

/*
 * On errors, negative value is written to fd.
 * On success: If query produced a result, the result_shmid is written to fd.
 * Otherwise, zero is written.
 */
static int call_callback(int fd, int query_shmid)
{
        void *query_shm, *result_shm;
        struct callback_query *cq;
        struct callback_result *cr;
        struct osl_object query, result = {.data = NULL};
        int result_shmid = -1, ret, ret2;

        ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
        if (ret < 0)
                goto out;
        cq = query_shm;
        query.data = (char *)query_shm + sizeof(*cq);
        query.size = cq->query_size;
        ret = cq->handler(&query, &result);
        ret2 = shm_detach(query_shm);
        if (ret2 < 0 && ret >= 0)
                ret = ret2;
        if (ret < 0)
                goto out;
        ret = 0;
        if (!result.data || !result.size)
                goto out;
        ret = shm_new(result.size + sizeof(struct callback_result));
        if (ret < 0)
                goto out;
        result_shmid = ret;
        ret = shm_attach(result_shmid, ATTACH_RW, &result_shm);
        if (ret < 0)
                goto out;
        cr = result_shm;
        cr->result_size = result.size;
        memcpy(result_shm + sizeof(*cr), result.data, result.size);
        ret = shm_detach(result_shm);
        if (ret < 0)
                goto out;
        ret = result_shmid;
out:
        free(result.data);
        ret2 = send_bin_buffer(fd, (char *)&ret, sizeof(int));
        if (ret < 0 || ret2 < 0) {
                if (result_shmid >= 0)
                        if (shm_destroy(result_shmid) < 0)
                                PARA_ERROR_LOG("destroy result failed\n");
                if (ret >= 0)
                        ret = ret2;
        }
        return ret;
}

static void command_post_select(struct sched *s, struct task *t)
{
        struct command_task *ct = t->private_data;
        struct sockaddr_un unix_addr;
        char buf[sizeof(uint32_t) + sizeof(int)];
        uint32_t cookie;
        int query_shmid, fd;

        t->ret = 1;
        if (!FD_ISSET(ct->fd, &s->rfds))
                return;
        t->ret = para_accept(ct->fd, &unix_addr, sizeof(unix_addr));
        if (t->ret < 0)
                return;
        /*
         * The following errors may be caused by a malicious local user. So do
         * not return an error in this case as this would terminate  para_afs
         * and para_server.
         */
        fd = t->ret;
        /* FIXME: This is easily dosable (peer doesn't send data) */
        t->ret = recv_bin_buffer(fd, buf, sizeof(buf));
        if (t->ret < 0) {
                PARA_NOTICE_LOG("%s (%d)\n", PARA_STRERROR(-t->ret), t->ret);
                goto out;
        }
        if (t->ret != sizeof(buf)) {
                PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
                        t->ret, (long unsigned) sizeof(buf));
                goto out;
        }
        cookie = *(uint32_t *)buf;
        if (cookie != ct->cookie) {
                PARA_NOTICE_LOG("received invalid cookie(got %u, expected %u)\n",
                        (unsigned)cookie, (unsigned)ct->cookie);
                goto out;
        }
        query_shmid = *(int *)(buf + sizeof(cookie));
        if (query_shmid < 0) {
                PARA_WARNING_LOG("received invalid query shmid %d)\n",
                        query_shmid);
                goto out;
        }
        /* Ignore return value: Errors might be ok here. */
        call_callback(fd, query_shmid);
out:
        t->ret = 1;
        close(fd);
}

static void register_command_task(uint32_t cookie)
{
        struct command_task *ct = &command_task_struct;
        ct->fd = setup_command_socket_or_die();
        ct->cookie = cookie;

        ct->task.pre_select = command_pre_select;
        ct->task.post_select = command_post_select;
        ct->task.private_data = ct;
        sprintf(ct->task.status, "command task");
        register_task(&ct->task);
}

void register_tasks(uint32_t cookie)
{
        register_signal_task();
        register_command_task(cookie);
}

static char *database_dir;

static int make_database_dir(void)
{
        int ret;

        if (!database_dir) {
                if (conf.afs_database_dir_given)
                        database_dir = para_strdup(conf.afs_database_dir_arg);
                else {
                        char *home = para_homedir();
                        database_dir = make_message(
                                "%s/.paraslash/afs_database", home);
                        free(home);
                }
        }
        PARA_INFO_LOG("afs_database dir %s\n", database_dir);
        ret = para_mkdir(database_dir, 0777);
        if (ret >= 0 || ret == -E_EXIST)
                return 1;
        free(database_dir);
        database_dir = NULL;
        return ret;
}

static int open_afs_tables(void)
{
        int ret = make_database_dir();

        if (ret < 0)
                return ret;
        ret = attribute_init(&afs_tables[TBLNUM_ATTRIBUTES], database_dir);
        if (ret < 0)
                return ret;
        ret = moods_init(&afs_tables[TBLNUM_MOODS], database_dir);
        if (ret < 0)
                goto moods_init_error;
        ret = playlists_init(&afs_tables[TBLNUM_PLAYLIST], database_dir);
        if (ret < 0)
                goto playlists_init_error;
        ret = lyrics_init(&afs_tables[TBLNUM_LYRICS], database_dir);
        if (ret < 0)
                goto lyrics_init_error;
        ret = images_init(&afs_tables[TBLNUM_IMAGES], database_dir);
        if (ret < 0)
                goto images_init_error;
        ret = score_init(&afs_tables[TBLNUM_SCORES], database_dir);
        if (ret < 0)
                goto score_init_error;
        ret = aft_init(&afs_tables[TBLNUM_AUDIO_FILES], database_dir);
        if (ret < 0)
                goto aft_init_error;
        return 1;

aft_init_error:
        score_shutdown(OSL_MARK_CLEAN);
score_init_error:
        images_shutdown(OSL_MARK_CLEAN);
images_init_error:
        lyrics_shutdown(OSL_MARK_CLEAN);
lyrics_init_error:
        playlists_shutdown(OSL_MARK_CLEAN);
playlists_init_error:
        moods_shutdown(OSL_MARK_CLEAN);
moods_init_error:
        attribute_shutdown(OSL_MARK_CLEAN);
        return ret;
}

__noreturn int afs_init(uint32_t cookie, int socket_fd)
{
        enum play_mode current_play_mode;
        struct sched s;
        int ret = open_afs_tables();

        if (ret < 0) {
                PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
                exit(EXIT_FAILURE);
        }
        server_socket = socket_fd;
        PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
                server_socket, (unsigned) cookie);
        current_play_mode = init_admissible_files();
        register_tasks(cookie);
        s.default_timeout.tv_sec = 0;
        s.default_timeout.tv_usec = 99 * 1000;
        ret = sched(&s);
        if (ret < 0)
                PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
        close_afs_tables(OSL_MARK_CLEAN);
        exit(EXIT_FAILURE);
}

static int create_tables_callback(const struct osl_object *query,
                __a_unused struct osl_object *result)
{
        uint32_t table_mask = *(uint32_t *)query->data;
        int i, ret;

        close_afs_tables(OSL_MARK_CLEAN);
        for (i = 0; i < NUM_AFS_TABLES; i++) {
                struct table_info *ti = afs_tables + i;

                if (ti->flags & TBLFLAG_SKIP_CREATE)
                        continue;
                if (!(table_mask & (1 << i)))
                        continue;
                ret = osl_create_table(ti->desc);
                if (ret < 0)
                        return ret;
        }
        ret = open_afs_tables();
        return ret < 0? ret: 0;
}

int com_init(int fd, int argc, char * const * const argv)
{
        int i, j, ret;
        uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
        struct osl_object query = {.data = &table_mask,
                .size = sizeof(table_mask)};

        if (argc != 1) {
                table_mask = 0;
                for (i = 1; i < argc; i++) {
                        for (j = 0; j < NUM_AFS_TABLES; j++) {
                                struct table_info *ti = afs_tables + j;

                                if (ti->flags & TBLFLAG_SKIP_CREATE)
                                        continue;
                                if (strcmp(argv[i], ti->desc->name))
                                        continue;
                                table_mask |= (1 << j);
                                break;
                        }
                        if (j == NUM_AFS_TABLES)
                                return -E_BAD_TABLE_NAME;
                }
        }
        ret = send_callback_request(create_tables_callback, &query, NULL);
        if (ret < 0)
                return ret;
        return send_va_buffer(fd, "successfully created afs table(s)\n");
}