Libc-583.tar.gz

[apple/libc.git] / gen / asl_store.c

/*
 * Copyright (c) 2007-2009 Apple Inc.  All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * "Portions Copyright (c) 2007 Apple Inc.  All Rights
 * Reserved.  This file contains Original Code and/or Modifications of
 * Original Code as defined in and that are subject to the Apple Public
 * Source License Version 1.0 (the 'License').  You may not use this file
 * except in compliance with the License.  Please obtain a copy of the
 * License at http://www.apple.com/publicsource and read it before using
 * this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License."
 * 
 * @APPLE_LICENSE_HEADER_END@
 */

#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <dirent.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <asl.h>
#include <asl_private.h>
#include <asl_core.h>
#include <asl_store.h>
#include <notify.h>

extern time_t asl_parse_time(const char *str);
extern uint64_t asl_file_cursor(asl_file_t *s);
extern uint32_t asl_file_match_start(asl_file_t *s, uint64_t start_id, int32_t direction);
extern uint32_t asl_file_match_next(asl_file_t *s, aslresponse query, asl_msg_t **msg, uint64_t *last_id, int32_t direction, int32_t ruid, int32_t rgid);

#define SECONDS_PER_DAY 86400

/* 
 * The ASL Store is organized as a set of files in a common directory.
 * Files are prefixed by the date (YYYY.MM.DD) of their contents.
 *
 * Messages with no access controls are saved in YYYY.MM.DD.asl
 * Messages with access limited to UID uuu are saved in YYYY.MM.DD.Uuuu.asl
 * Messages with access limited to GID ggg are saved in YYYY.MM.DD.Gggg.asl
 * Messages with access limited to UID uuu and GID ggg are saved in YYYY.MM.DD.Uuuu.Gggg.asl
 *
 * Messages that have a value for ASLExpireTime are saved in BB.YYYY.MM.DD.asl
 * where the timestamp is the "Best Before" date of the file.  Access controls
 * are implemented as above with Uuuu and Gggg in the file name.  Note that the
 * Best Before files are for the last day of the month, so a single file contains
 * messages that expire in that month.
 *
 * An external tool runs daily and deletes "old" files.
 */

static time_t
_asl_start_today()
{
        time_t now;
        struct tm ctm;

        memset(&ctm, 0, sizeof(struct tm));
        now = time(NULL);

        if (localtime_r((const time_t *)&now, &ctm) == NULL) return 0;

        ctm.tm_sec = 0;
        ctm.tm_min = 0;
        ctm.tm_hour = 0;

        return mktime(&ctm);
}

/*
 * The base directory contains a data file which stores
 * the last record ID.
 *
 * | MAX_ID (uint64_t) |
 *
 */
uint32_t
asl_store_open_write(const char *basedir, asl_store_t **s)
{
        asl_store_t *out;
        struct stat sb;
        uint32_t i, flags;
        char *path;
        FILE *sd;
        uint64_t last_id;
        time_t start;

        if (s == NULL) return ASL_STATUS_INVALID_ARG;

        start = _asl_start_today();
        if (start == 0) return ASL_STATUS_FAILED;

        if (basedir == NULL) basedir = PATH_ASL_STORE;

        memset(&sb, 0, sizeof(struct stat));
        if (stat(basedir, &sb) != 0) return ASL_STATUS_INVALID_STORE;
        if ((sb.st_mode & S_IFDIR) == 0) return ASL_STATUS_INVALID_STORE;

        path = NULL;
        asprintf(&path, "%s/%s", basedir, FILE_ASL_STORE_DATA);
        if (path == NULL) return ASL_STATUS_NO_MEMORY;

        sd = NULL;

        memset(&sb, 0, sizeof(struct stat));
        if (stat(path, &sb) != 0)
        {
                if (errno != ENOENT)
                {
                        free(path);
                        return ASL_STATUS_FAILED;
                }

                sd = fopen(path, "w+");
                free(path);

                if (sd == NULL) return ASL_STATUS_FAILED;

                last_id = 0;

                /* Create new StoreData file (8 bytes ID + 4 bytes flags) */

                if (fwrite(&last_id, sizeof(uint64_t), 1, sd) != 1)
                {
                        fclose(sd);
                        return ASL_STATUS_WRITE_FAILED;
                }

                flags = 0;
                if (fwrite(&flags, sizeof(uint32_t), 1, sd) != 1)
                {
                        fclose(sd);
                        return ASL_STATUS_WRITE_FAILED;
                }
        }
        else
        {
                sd = fopen(path, "r+");
                free(path);

                if (sd == NULL) return ASL_STATUS_FAILED;
                if (fread(&last_id, sizeof(uint64_t), 1, sd) != 1)
                {
                        fclose(sd);
                        return ASL_STATUS_READ_FAILED;
                }

                last_id = asl_core_ntohq(last_id);
        }

        out = (asl_store_t *)calloc(1, sizeof(asl_store_t));
        if (out == NULL)
        {
                fclose(sd);
                return ASL_STATUS_NO_MEMORY;
        }

        if (basedir == NULL) out->base_dir = strdup(PATH_ASL_STORE);
        else out->base_dir = strdup(basedir);

        if (out->base_dir == NULL)
        {
                fclose(sd);
                free(out);
                return ASL_STATUS_NO_MEMORY;
        }

        out->start_today = start;
        out->start_tomorrow = out->start_today + SECONDS_PER_DAY;
        out->storedata = sd;
        out->next_id = last_id + 1;

        for (i = 0; i < FILE_CACHE_SIZE; i++)
        {
                memset(&out->file_cache[i], 0, sizeof(asl_cached_file_t));
                out->file_cache[i].u = -1;
                out->file_cache[i].g = -1;
        }

        *s = out;
        return ASL_STATUS_OK;
}

uint32_t
asl_store_statistics(asl_store_t *s, aslmsg *msg)
{
        aslmsg out;

        if (s == NULL) return ASL_STATUS_INVALID_STORE;
        if (msg == NULL) return ASL_STATUS_INVALID_ARG;

        out = (aslmsg)calloc(1, sizeof(asl_msg_t));
        if (out == NULL) return ASL_STATUS_NO_MEMORY;

        /* does nothing for now */

        *msg = out;
        return ASL_STATUS_OK;
}

uint32_t
asl_store_open_read(const char *basedir, asl_store_t **s)
{
        asl_store_t *out;
        struct stat sb;

        if (s == NULL) return ASL_STATUS_INVALID_ARG;

        if (basedir == NULL) basedir = PATH_ASL_STORE;

        memset(&sb, 0, sizeof(struct stat));
        if (stat(basedir, &sb) != 0) return ASL_STATUS_INVALID_STORE;
        if ((sb.st_mode & S_IFDIR) == 0) return ASL_STATUS_INVALID_STORE;

        out = (asl_store_t *)calloc(1, sizeof(asl_store_t));
        if (out == NULL) return ASL_STATUS_NO_MEMORY;

        if (basedir == NULL) out->base_dir = strdup(PATH_ASL_STORE);
        else out->base_dir = strdup(basedir);

        if (out->base_dir == NULL)
        {
                free(out);
                return ASL_STATUS_NO_MEMORY;
        }

        *s = out;
        return ASL_STATUS_OK;
}

uint32_t
asl_store_max_file_size(asl_store_t *s, size_t max)
{
        if (s == NULL) return ASL_STATUS_INVALID_STORE;

        s->max_file_size = max;
        return ASL_STATUS_OK;
}

void
asl_store_file_closeall(asl_store_t *s)
{
        uint32_t i;

        if (s == NULL) return;

        for (i = 0; i < FILE_CACHE_SIZE; i++)
        {
                if (s->file_cache[i].f != NULL) asl_file_close(s->file_cache[i].f);
                s->file_cache[i].f = NULL;
                if (s->file_cache[i].path != NULL) free(s->file_cache[i].path);
                s->file_cache[i].path = NULL;
                s->file_cache[i].u = -1;
                s->file_cache[i].g = -1;
                s->file_cache[i].bb = 0;
                s->file_cache[i].ts = 0;
        }
}

uint32_t
asl_store_close(asl_store_t *s)
{
        if (s == NULL) return ASL_STATUS_OK;

        if (s->base_dir != NULL) free(s->base_dir);
        s->base_dir = NULL;
        asl_store_file_closeall(s);
        if (s->storedata != NULL) fclose(s->storedata);

        free(s);

        return ASL_STATUS_OK;
}

uint32_t
asl_store_signal_sweep(asl_store_t *s)
{
        char *str;
        int semfd;
        uint64_t xid;
        uint32_t status;

        if (s == NULL) return ASL_STATUS_INVALID_STORE;

        asprintf(&str, "%s/%s", s->base_dir, FILE_ASL_STORE_SWEEP_SEMAPHORE);
        if (str == NULL) return ASL_STATUS_NO_MEMORY;

        semfd = open(str, O_WRONLY | O_CREAT | O_NONBLOCK, 0644);
        free(str);

        if (semfd <  0) return ASL_STATUS_WRITE_FAILED;

        status = ASL_STATUS_OK;

        /* write the current message ID in the SweepStore file */
        xid = asl_core_htonq(s->next_id - 1);
        if (write(semfd, &xid, sizeof(uint64_t)) != sizeof(uint64_t)) status = ASL_STATUS_WRITE_FAILED;

        close(semfd);
        return status;
}

/*
 * Sweep the file cache.
 * Close any files that have not been used in the last FILE_CACHE_TTL seconds.
 * Returns least recently used or unused cache slot.
 */
static uint32_t
asl_store_file_cache_lru(asl_store_t *s, time_t now, uint32_t ignorex)
{
        time_t min;
        uint32_t i, x;

        if (s == NULL) return 0;

        x = 0;
        min = now - FILE_CACHE_TTL;

        for (i = 0; i < FILE_CACHE_SIZE; i++)
        {
                if ((i != ignorex) && (s->file_cache[i].ts < min))
                {
                        asl_file_close(s->file_cache[i].f);
                        s->file_cache[i].f = NULL;
                        if (s->file_cache[i].path != NULL) free(s->file_cache[i].path);
                        s->file_cache[i].path = NULL;
                        s->file_cache[i].u = -1;
                        s->file_cache[i].g = -1;
                        s->file_cache[i].bb = 0;
                        s->file_cache[i].ts = 0;
                }

                if (s->file_cache[i].ts < s->file_cache[x].ts) x = i;
        }

        return x;
}

uint32_t
asl_store_sweep_file_cache(asl_store_t *s)
{
        if (s == NULL) return ASL_STATUS_INVALID_STORE;

        asl_store_file_cache_lru(s, time(NULL), FILE_CACHE_SIZE);
        return ASL_STATUS_OK;
}

static uint32_t
asl_store_file_open_write(asl_store_t *s, char *tstring, int32_t ruid, int32_t rgid, time_t bb, asl_file_t **f, time_t now, uint32_t check_cache)
{
        char *path;
        mode_t m;
        int32_t i, x, u, g;
        uint32_t status;
        asl_file_t *out;

        if (s == NULL) return ASL_STATUS_INVALID_STORE;

        /* see if the file is already open and in the cache */
        for (i = 0; i < FILE_CACHE_SIZE; i++)
        {
                if ((s->file_cache[i].u == ruid) && (s->file_cache[i].g == rgid) && (s->file_cache[i].bb == bb) && (s->file_cache[i].f != NULL))
                {
                        s->file_cache[i].ts = now;
                        *f = s->file_cache[i].f;
                        if (check_cache == 1) asl_store_file_cache_lru(s, now, i);
                        return ASL_STATUS_OK;
                }
        }

        path = NULL;
        u = 0;
        g = 0;
        m = 0644;

        if (ruid == -1)
        {
                if (rgid == -1)
                {
                        asprintf(&path, "%s/%s.asl", s->base_dir, tstring);
                }
                else
                {
                        g = rgid;
                        m = 0640;
                        asprintf(&path, "%s/%s.G%d.asl", s->base_dir, tstring, g);
                }
        }
        else
        {
                u = ruid;
                if (rgid == -1)
                {
                        m = 0600;
                        asprintf(&path, "%s/%s.U%d.asl", s->base_dir, tstring, u);
                }
                else
                {
                        g = rgid;
                        m = 0640;
                        asprintf(&path, "%s/%s.U%d.G%u.asl", s->base_dir, tstring, u, g);
                }
        }

        if (path == NULL) return ASL_STATUS_NO_MEMORY;

        out = NULL;
        status = asl_file_open_write(path, m, u, g, &out);
        if (status != ASL_STATUS_OK)
        {
                free(path);
                return status;
        }

        x = asl_store_file_cache_lru(s, now, FILE_CACHE_SIZE);
        if (s->file_cache[x].f != NULL) asl_file_close(s->file_cache[x].f);
        if (s->file_cache[x].path != NULL) free(s->file_cache[x].path);

        s->file_cache[x].f = out;
        s->file_cache[x].path = path;
        s->file_cache[x].u = ruid;
        s->file_cache[x].g = rgid;
        s->file_cache[x].bb = bb;
        s->file_cache[x].ts = time(NULL);

        *f = out;

        return ASL_STATUS_OK;
}

char *
asl_store_file_path(asl_store_t *s, asl_file_t *f)
{
        uint32_t i;

        if (s == NULL) return NULL;

        for (i = 0; i < FILE_CACHE_SIZE; i++)
        {
                if (s->file_cache[i].f == f)
                {
                        if (s->file_cache[i].path == NULL) return NULL;
                        return strdup(s->file_cache[i].path);
                }
        }

        return NULL;
}

void
asl_store_file_close(asl_store_t *s, asl_file_t *f)
{
        uint32_t i;

        if (s == NULL) return;
        if (f == NULL) return;

        for (i = 0; i < FILE_CACHE_SIZE; i++)
        {
                if (s->file_cache[i].f == f)
                {
                        asl_file_close(s->file_cache[i].f);
                        s->file_cache[i].f = NULL;
                        if (s->file_cache[i].path != NULL) free(s->file_cache[i].path);
                        s->file_cache[i].path = NULL;
                        s->file_cache[i].u = -1;
                        s->file_cache[i].g = -1;
                        s->file_cache[i].bb = 0;
                        s->file_cache[i].ts = 0;
                        return;
                }
        }
}

uint32_t
asl_store_save(asl_store_t *s, aslmsg msg)
{
        struct tm ctm;
        time_t msg_time, now, bb;
        char *path, *tmp_path, *tstring, *scratch;
        const char *val;
        uid_t ruid;
        gid_t rgid;
        asl_file_t *f;
        uint32_t status, check_cache, signal_sweep, len;
        uint64_t xid, ftime;
        size_t fsize;

        if (s == NULL) return ASL_STATUS_INVALID_STORE;
        if (msg == NULL) return ASL_STATUS_INVALID_ARG;

        now = time(NULL);

        check_cache = 0;
        if ((s->last_write + FILE_CACHE_TTL) <= now) check_cache = 1;

        signal_sweep = 0;

        msg_time = 0;
        val = asl_get(msg, ASL_KEY_TIME);
        if (val == NULL) msg_time = now;
        else msg_time = asl_parse_time(val);

        if (msg_time >= s->start_tomorrow)
        {
                if (now >= s->start_tomorrow)
                {
                        /* new day begins */
                        check_cache = 0;
                        signal_sweep = 1;
                        asl_store_file_closeall(s);

                        /*
                         * _asl_start_today should never fail, but if it does,
                         * just push forward one day.  That will probably be correct, and if
                         * it isn't, the next message that gets saved will push it ahead again
                         * until we get to the right date.
                         */
                        s->start_today = _asl_start_today();
                        if (s->start_today == 0) s->start_today = s->start_tomorrow;

                        s->start_tomorrow = s->start_today + SECONDS_PER_DAY;
                }
        }

        val = asl_get(msg, ASL_KEY_READ_UID);
        ruid = -1;
        if (val != NULL) ruid = atoi(val);

        val = asl_get(msg, ASL_KEY_READ_GID);
        rgid = -1;
        if (val != NULL) rgid = atoi(val);

        bb = 0;
        val = asl_get(msg, ASL_KEY_EXPIRE_TIME);
        if (val != NULL)
        {
                bb = 1;
                msg_time = asl_parse_time(val);
        }

        if (fseeko(s->storedata, 0, SEEK_SET) != 0) return ASL_STATUS_WRITE_FAILED;

        xid = asl_core_htonq(s->next_id);
        if (fwrite(&xid, sizeof(uint64_t), 1, s->storedata) != 1) return ASL_STATUS_WRITE_FAILED;

        xid = s->next_id;
        s->next_id++;

        s->last_write = now;

        if (localtime_r((const time_t *)&msg_time, &ctm) == NULL) return ASL_STATUS_FAILED;

        tstring = NULL;
        if (bb == 1)
        {
                /*
                 * This supports 12 monthy "Best Before" buckets.
                 * We advance the actual expiry time to day zero of the following month.
                 * mktime() is clever enough to know that you actually mean the last day
                 * of the previous month.  What we get back from localtime is the last
                 * day of the month in which the message expires, which we use in the name.
                 */
                ctm.tm_sec = 0;
                ctm.tm_min = 0;
                ctm.tm_hour = 0;
                ctm.tm_mday = 0;
                ctm.tm_mon += 1;

                bb = mktime(&ctm);

                if (localtime_r((const time_t *)&bb, &ctm) == NULL) return ASL_STATUS_FAILED;
                asprintf(&tstring, "BB.%d.%02d.%02d", ctm.tm_year + 1900, ctm.tm_mon + 1, ctm.tm_mday);
        }
        else
        {
                asprintf(&tstring, "%d.%02d.%02d", ctm.tm_year + 1900, ctm.tm_mon + 1, ctm.tm_mday);
        }

        if (tstring == NULL) return ASL_STATUS_NO_MEMORY;

        status = asl_store_file_open_write(s, tstring, ruid, rgid, bb, &f, now, check_cache);
        free(tstring);
        tstring = NULL;

        if (status != ASL_STATUS_OK) return status;

        status = asl_file_save(f, msg, &xid);
        if (status != ASL_STATUS_OK) return status;

        fsize = asl_file_size(f);
        ftime = asl_file_ctime(f);

        /* if file is larger than max_file_size, rename it and touch semaphore file in the store */
        if ((s->max_file_size != 0) && (fsize > s->max_file_size))
        {
                signal_sweep = 1;
                status = ASL_STATUS_OK;

                path = asl_store_file_path(s, f);

                asl_store_file_close(s, f);

                if (path != NULL)
                {
                        tmp_path = NULL;

                        len = strlen(path);
                        if ((len >= 4) && (!strcmp(path + len - 4, ".asl")))
                        {
                                /* rename xxxxxxx.asl to xxxxxxx.timestamp.asl */
                                scratch = strdup(path);
                                if (scratch != NULL)
                                {
                                        scratch[len - 4] = '\0';
                                        asprintf(&tmp_path, "%s.%llu.asl", scratch, ftime);
                                        free(scratch);

                                }
                        }
                        else
                        {
                                /* append timestamp */
                                asprintf(&tmp_path, "%s.%llu", path, ftime);
                        }

                        if (tmp_path == NULL)
                        {
                                status = ASL_STATUS_NO_MEMORY;
                        }
                        else
                        {
                                if (rename(path, tmp_path) != 0) status = ASL_STATUS_FAILED;
                                free(tmp_path);
                        }

                        free(path);
                }
        }

        if (signal_sweep != 0) asl_store_signal_sweep(s);

        return status;
}

uint32_t
asl_store_match_timeout(asl_store_t *s, aslresponse query, aslresponse *res, uint64_t *last_id, uint64_t start_id, uint32_t count, int32_t direction, uint32_t usec)
{
        DIR *dp;
        struct dirent *dent;
        uint32_t status;
        asl_file_t *f;
        char *path;
        asl_file_list_t *files;

        if (s == NULL) return ASL_STATUS_INVALID_STORE;
        if (res == NULL) return ASL_STATUS_INVALID_ARG;

        files = NULL;

        /*
         * Open all readable files
         */
        dp = opendir(s->base_dir);
        if (dp == NULL) return ASL_STATUS_READ_FAILED;

        while ((dent = readdir(dp)) != NULL)
        {
                if (dent->d_name[0] == '.') continue;

                path = NULL;
                asprintf(&path, "%s/%s", s->base_dir, dent->d_name);

                /* NB asl_file_open_read will fail if path is NULL, if the file is not an ASL store file, or if it isn't readable */
                status = asl_file_open_read(path, &f);
                if (path != NULL) free(path);
                if ((status != ASL_STATUS_OK) || (f == NULL)) continue;

                files = asl_file_list_add(files, f);
        }

        closedir(dp);

        status = asl_file_list_match_timeout(files, query, res, last_id, start_id, count, direction, usec);
        asl_file_list_close(files);
        return status;
}

uint32_t
asl_store_match(asl_store_t *s, aslresponse query, aslresponse *res, uint64_t *last_id, uint64_t start_id, uint32_t count, int32_t direction)
{
        return asl_store_match_timeout(s, query, res, last_id, start_id, count, direction, 0);
}

uint32_t
asl_store_match_start(asl_store_t *s, uint64_t start_id, int32_t direction)
{
        DIR *dp;
        struct dirent *dent;
        uint32_t status;
        asl_file_t *f;
        char *path;
        asl_file_list_t *files;

        if (s == NULL) return ASL_STATUS_INVALID_STORE;

        if (s->work != NULL) asl_file_list_match_end(s->work);
        s->work = NULL;

        files = NULL;

        /*
         * Open all readable files
         */
        dp = opendir(s->base_dir);
        if (dp == NULL) return ASL_STATUS_READ_FAILED;

        while ((dent = readdir(dp)) != NULL)
        {
                if (dent->d_name[0] == '.') continue;

                path = NULL;
                asprintf(&path, "%s/%s", s->base_dir, dent->d_name);

                /* NB asl_file_open_read will fail if path is NULL, if the file is not an ASL store file, or if it isn't readable */
                status = asl_file_open_read(path, &f);
                if (path != NULL) free(path);
                if ((status != ASL_STATUS_OK) || (f == NULL)) continue;

                files = asl_file_list_add(files, f);
        }

        closedir(dp);

        s->work = asl_file_list_match_start(files, start_id, direction);
        if (s->work == NULL) return ASL_STATUS_FAILED;

        return ASL_STATUS_OK;
}

uint32_t
asl_store_match_next(asl_store_t *s, aslresponse query, aslresponse *res, uint32_t count)
{
        if (s == NULL) return ASL_STATUS_INVALID_STORE;
        if (s->work == NULL) return ASL_STATUS_OK;

        return asl_file_list_match_next(s->work, query, res, count);
}