src/lib-index/mail-index.c

	mail-index.c revision 1fd0d511885c30028aba388588151acf4ee85e75
964N/A/* Copyright (C) 2003-2004 Timo Sirainen */
964N/A
964N/A#include "lib.h"
964N/A#include "ioloop.h"
964N/A#include "array.h"
964N/A#include "buffer.h"
964N/A#include "hash.h"
964N/A#include "mmap-util.h"
964N/A#include "nfs-workarounds.h"
964N/A#include "read-full.h"
964N/A#include "write-full.h"
964N/A#include "mail-index-private.h"
964N/A#include "mail-index-view-private.h"
964N/A#include "mail-index-sync-private.h"
964N/A#include "mail-transaction-log.h"
964N/A#include "mail-cache.h"
964N/A
964N/A#include <stdio.h>
964N/A#include <stddef.h>
964N/A#include <time.h>
964N/A#include <sys/stat.h>
964N/A
964N/Astruct mail_index_module_register mail_index_module_register = { 0 };
964N/A
964N/Astruct mail_index *mail_index_alloc(const char *dir, const char *prefix)
964N/A{
964N/A    struct mail_index *index;
964N/A
964N/A    index = i_new(struct mail_index, 1);
964N/A    index->dir = i_strdup(dir);
964N/A    index->prefix = i_strdup(prefix);
964N/A    index->fd = -1;
964N/A
964N/A    index->extension_pool =
964N/A        pool_alloconly_create(MEMPOOL_GROWING"index extension", 1024);
964N/A    p_array_init(&index->extensions, index->extension_pool, 5);
964N/A    i_array_init(&index->sync_lost_handlers, 4);
964N/A    i_array_init(&index->module_contexts,
964N/A             I_MIN(5, mail_index_module_register.id));
964N/A
964N/A    index->mode = 0600;
964N/A    index->gid = (gid_t)-1;
964N/A
964N/A    index->keywords_ext_id =
964N/A        mail_index_ext_register(index, "keywords", 128, 2, 1);
964N/A    index->keywords_pool = pool_alloconly_create("keywords", 512);
964N/A    i_array_init(&index->keywords, 16);
964N/A    index->keywords_hash =
964N/A        hash_create(default_pool, index->keywords_pool, 0,
964N/A                strcase_hash, (hash_cmp_callback_t *)strcasecmp);
964N/A    index->log = mail_transaction_log_alloc(index);
964N/A    return index;
964N/A}
964N/A
964N/Avoid mail_index_free(struct mail_index **_index)
964N/A{
964N/A    struct mail_index *index = *_index;
964N/A
964N/A    *_index = NULL;
964N/A    mail_index_close(index);
964N/A
964N/A    mail_transaction_log_free(&index->log);
964N/A    hash_destroy(index->keywords_hash);
964N/A    pool_unref(index->extension_pool);
964N/A    pool_unref(index->keywords_pool);
964N/A
982N/A    array_free(&index->sync_lost_handlers);
964N/A    array_free(&index->keywords);
964N/A    array_free(&index->module_contexts);
964N/A
964N/A    i_free(index->error);
964N/A    i_free(index->dir);
964N/A    i_free(index->prefix);
964N/A    i_free(index);
964N/A}
964N/A
964N/Avoid mail_index_set_permissions(struct mail_index *index,
964N/A                mode_t mode, gid_t gid)
964N/A{
964N/A    index->mode = mode & 0666;
964N/A    index->gid = gid;
964N/A}
964N/A
964N/Auint32_t mail_index_ext_register(struct mail_index *index, const char *name,
964N/A                 uint32_t default_hdr_size,
964N/A                 uint16_t default_record_size,
964N/A                 uint16_t default_record_align)
964N/A{
964N/A        const struct mail_index_registered_ext *extensions;
964N/A    struct mail_index_registered_ext rext;
964N/A    unsigned int i, ext_count;
964N/A
964N/A    extensions = array_get(&index->extensions, &ext_count);
964N/A
964N/A    /* see if it's already there */
964N/A    for (i = 0; i < ext_count; i++) {
964N/A        if (strcmp(extensions[i].name, name) == 0)
964N/A            return i;
964N/A    }
964N/A
964N/A    memset(&rext, 0, sizeof(rext));
964N/A    rext.name = p_strdup(index->extension_pool, name);
    rext.index_idx = ext_count;
    rext.hdr_size = default_hdr_size;
    rext.record_size = default_record_size;
    rext.record_align = default_record_align;

    array_append(&index->extensions, &rext, 1);
    return ext_count;
}

void mail_index_register_expunge_handler(struct mail_index *index,
                     uint32_t ext_id, bool call_always,
                     mail_index_expunge_handler_t *cb,
                     void *context)
{
    struct mail_index_registered_ext *rext;

    rext = array_idx_modifiable(&index->extensions, ext_id);
    i_assert(rext->expunge_handler == NULL || rext->expunge_handler == cb);

    rext->expunge_handler = cb;
    rext->expunge_context = context;
    rext->expunge_handler_call_always = call_always;
}

void mail_index_unregister_expunge_handler(struct mail_index *index,
                       uint32_t ext_id)
{
    struct mail_index_registered_ext *rext;

    rext = array_idx_modifiable(&index->extensions, ext_id);
    i_assert(rext->expunge_handler != NULL);

    rext->expunge_handler = NULL;
}

void mail_index_register_sync_handler(struct mail_index *index, uint32_t ext_id,
                      mail_index_sync_handler_t *cb,
                      enum mail_index_sync_handler_type type)
{
    struct mail_index_registered_ext *rext;

    rext = array_idx_modifiable(&index->extensions, ext_id);
    i_assert(rext->sync_handler.callback == NULL);

    rext->sync_handler.callback = cb;
    rext->sync_handler.type = type;
}

void mail_index_unregister_sync_handler(struct mail_index *index,
                    uint32_t ext_id)
{
    struct mail_index_registered_ext *rext;

    rext = array_idx_modifiable(&index->extensions, ext_id);
    i_assert(rext->sync_handler.callback != NULL);

    rext->sync_handler.callback = NULL;
    rext->sync_handler.type = 0;
}

void mail_index_register_sync_lost_handler(struct mail_index *index,
                       mail_index_sync_lost_handler_t *cb)
{
    array_append(&index->sync_lost_handlers, &cb, 1);
}

void mail_index_unregister_sync_lost_handler(struct mail_index *index,
                         mail_index_sync_lost_handler_t *cb)
{
    mail_index_sync_lost_handler_t *const *handlers;
    unsigned int i, count;

    handlers = array_get(&index->sync_lost_handlers, &count);
    for (i = 0; i < count; i++) {
        if (handlers[i] == cb) {
            array_delete(&index->sync_lost_handlers, i, 1);
            break;
        }
    }
}

bool mail_index_keyword_lookup(struct mail_index *index,
                   const char *keyword, unsigned int *idx_r)
{
    void *value;

    /* keywords_hash keeps a name => index mapping of keywords.
       Keywords are never removed from it, so the index values are valid
       for the lifetime of the mail_index. */
    if (hash_lookup_full(index->keywords_hash, keyword, NULL, &value)) {
        *idx_r = POINTER_CAST_TO(value, unsigned int);
        return TRUE;
    }

    *idx_r = (unsigned int)-1;
    return FALSE;
}

void mail_index_keyword_lookup_or_create(struct mail_index *index,
                     const char *keyword,
                     unsigned int *idx_r)
{
    char *keyword_dup;

    i_assert(*keyword != '\0');

    if (mail_index_keyword_lookup(index, keyword, idx_r))
        return;

    keyword = keyword_dup = p_strdup(index->keywords_pool, keyword);
    *idx_r = array_count(&index->keywords);

    hash_insert(index->keywords_hash, keyword_dup, POINTER_CAST(*idx_r));
    array_append(&index->keywords, &keyword, 1);
}

int mail_index_map_parse_keywords(struct mail_index_map *map)
{
    struct mail_index *index = map->index;
    const struct mail_index_ext *ext;
    const struct mail_index_keyword_header *kw_hdr;
    const struct mail_index_keyword_header_rec *kw_rec;
    const char *name;
    unsigned int i, name_area_end_offset, old_count;
    uint32_t idx;

    if (!mail_index_map_lookup_ext(map, "keywords", &idx)) {
        if (array_is_created(&map->keyword_idx_map))
            array_clear(&map->keyword_idx_map);
        return 0;
    }
    ext = array_idx(&map->extensions, idx);

    /* Extension header contains:
       - struct mail_index_keyword_header
       - struct mail_index_keyword_header_rec * keywords_count
       - const char names[] * keywords_count
    */
    i_assert(ext->hdr_offset < map->hdr.header_size);
    kw_hdr = CONST_PTR_OFFSET(map->hdr_base, ext->hdr_offset);
    kw_rec = (const void *)(kw_hdr + 1);
    name = (const char *)(kw_rec + kw_hdr->keywords_count);

    old_count = !array_is_created(&map->keyword_idx_map) ? 0 :
        array_count(&map->keyword_idx_map);

    /* Keywords can only be added into same mapping. Removing requires a
       new mapping (recreating the index file) */
    if (kw_hdr->keywords_count == old_count) {
        /* nothing changed */
        return 0;
    }

    /* make sure the header is valid */
    if (kw_hdr->keywords_count < old_count) {
        mail_index_set_error(index, "Corrupted index file %s: "
                     "Keywords removed unexpectedly",
                     index->filepath);
        return -1;
    }

    if ((size_t)(name - (const char *)kw_hdr) > ext->hdr_size) {
        mail_index_set_error(index, "Corrupted index file %s: "
                     "keywords_count larger than header size",
                     index->filepath);
        return -1;
    }

    name_area_end_offset = (const char *)kw_hdr + ext->hdr_size - name;
    for (i = 0; i < kw_hdr->keywords_count; i++) {
        if (kw_rec[i].name_offset > name_area_end_offset) {
            mail_index_set_error(index, "Corrupted index file %s: "
                "name_offset points outside allocated header",
                index->filepath);
            return -1;
        }
    }
    if (name[name_area_end_offset-1] != '\0') {
        mail_index_set_error(index, "Corrupted index file %s: "
                     "Keyword header doesn't end with NUL",
                     index->filepath);
        return -1;
    }

    /* create file -> index mapping */
    if (!array_is_created(&map->keyword_idx_map))
        i_array_init(&map->keyword_idx_map, kw_hdr->keywords_count);

#ifdef DEBUG
    /* Check that existing headers are still the same. It's behind DEBUG
       since it's pretty useless waste of CPU normally. */
    for (i = 0; i < array_count(&map->keyword_idx_map); i++) {
        const char *keyword = name + kw_rec[i].name_offset;
        const unsigned int *old_idx;
        unsigned int idx;

        old_idx = array_idx(&map->keyword_idx_map, i);
        if (!mail_index_keyword_lookup(index, keyword, &idx) ||
            idx != *old_idx) {
            mail_index_set_error(index, "Corrupted index file %s: "
                         "Keywords changed unexpectedly",
                         index->filepath);
            return -1;
        }
    }
#endif
    /* Register the newly seen keywords */
    i = array_count(&map->keyword_idx_map);
    for (; i < kw_hdr->keywords_count; i++) {
        const char *keyword = name + kw_rec[i].name_offset;
        unsigned int idx;

        if (*keyword == '\0') {
            mail_index_set_error(index, "Corrupted index file %s: "
                "Empty keyword name in header",
                index->filepath);
            return -1;
        }
        mail_index_keyword_lookup_or_create(index, keyword, &idx);
        array_append(&map->keyword_idx_map, &idx, 1);
    }
    return 0;
}

const ARRAY_TYPE(keywords) *mail_index_get_keywords(struct mail_index *index)
{
    return &index->keywords;
}

int mail_index_try_open_only(struct mail_index *index)
{
    i_assert(index->fd == -1);
    i_assert(!MAIL_INDEX_IS_IN_MEMORY(index));

        /* Note that our caller must close index->fd by itself. */
    index->fd = nfs_safe_open(index->filepath, O_RDWR);
    index->readonly = FALSE;

    if (index->fd == -1 && errno == EACCES) {
        index->fd = open(index->filepath, O_RDONLY);
        index->readonly = TRUE;
    }

    if (index->fd == -1) {
        if (errno != ENOENT)
            return mail_index_set_syscall_error(index, "open()");

        /* have to create it */
        return 0;
    }
    return 1;
}

static int
mail_index_try_open(struct mail_index *index)
{
    int ret;

        i_assert(index->fd == -1);

    if (MAIL_INDEX_IS_IN_MEMORY(index))
        return 0;

    i_assert(index->map == NULL || index->map->rec_map->lock_id == 0);
    ret = mail_index_map(index, MAIL_INDEX_SYNC_HANDLER_HEAD);
    if (ret == 0) {
        /* it's corrupted - recreate it */
        if (index->fd != -1) {
            if (close(index->fd) < 0)
                mail_index_set_syscall_error(index, "close()");
            index->fd = -1;
        }
    }
    return ret;
}

int mail_index_create_tmp_file(struct mail_index *index, const char **path_r)
{
        mode_t old_mask;
    const char *path;
    int fd;

    i_assert(!MAIL_INDEX_IS_IN_MEMORY(index));

    path = *path_r = t_strconcat(index->filepath, ".tmp", NULL);
    old_mask = umask(0);
    fd = open(path, O_RDWR|O_CREAT|O_TRUNC, index->mode);
    umask(old_mask);
    if (fd == -1)
        return mail_index_file_set_syscall_error(index, path, "open()");

    if (index->gid != (gid_t)-1 && fchown(fd, (uid_t)-1, index->gid) < 0) {
        mail_index_file_set_syscall_error(index, path, "fchown()");
        return -1;
    }

    return fd;
}

static int mail_index_open_files(struct mail_index *index,
                 enum mail_index_open_flags flags)
{
    int ret;
    bool created = FALSE;

    ret = mail_transaction_log_open(index->log);
    if (ret == 0) {
        if ((flags & MAIL_INDEX_OPEN_FLAG_CREATE) == 0)
            return 0;

        /* if dovecot.index exists, read it first so that we can get
           the correct indexid and log sequence */
        (void)mail_index_try_open(index);

        if (index->indexid == 0) {
            /* Create a new indexid for us. If we're opening index
               into memory, index->map doesn't exist yet. */
            index->indexid = ioloop_time;
            if (index->map != NULL)
                index->map->hdr.indexid = index->indexid;
        }

        ret = mail_transaction_log_create(index->log);
        created = TRUE;
    }
    if (ret >= 0) {
        ret = index->map != NULL ? 0 : mail_index_try_open(index);
        if (ret == 0) {
            /* doesn't exist / corrupted */
            mail_transaction_log_close(index->log);
            ret = mail_transaction_log_create(index->log);
            if (ret == 0) {
                if (index->map != NULL)
                    mail_index_unmap(&index->map);
                index->map = mail_index_map_alloc(index);
            }
        }
    }
    if (ret < 0) {
        /* open/create failed, fallback to in-memory indexes */
        if ((flags & MAIL_INDEX_OPEN_FLAG_CREATE) == 0)
            return -1;

        if (mail_index_move_to_memory(index) < 0)
            return -1;
    }

    index->cache = created ? mail_cache_create(index) :
        mail_cache_open_or_create(index);
    return 1;
}

int mail_index_open(struct mail_index *index, enum mail_index_open_flags flags,
            enum file_lock_method lock_method)
{
    int ret;

    if (index->opened) {
        if (index->map != NULL &&
            (index->map->hdr.flags &
             MAIL_INDEX_HDR_FLAG_CORRUPTED) != 0) {
            /* corrupted, reopen files */
                        mail_index_close(index);
        } else {
            i_assert(index->map != NULL);
            return 1;
        }
    }

    index->filepath = MAIL_INDEX_IS_IN_MEMORY(index) ?
        i_strdup("(in-memory index)") :
        i_strconcat(index->dir, "/", index->prefix, NULL);

    index->shared_lock_count = 0;
    index->excl_lock_count = 0;
    index->lock_type = F_UNLCK;
    index->lock_id_counter = 2;

    index->readonly = FALSE;
    index->nodiskspace = FALSE;
    index->index_lock_timeout = FALSE;
    index->log_locked = FALSE;
    index->mmap_disable = (flags & MAIL_INDEX_OPEN_FLAG_MMAP_DISABLE) != 0;
    index->use_excl_dotlocks =
        (flags & MAIL_INDEX_OPEN_FLAG_DOTLOCK_USE_EXCL) != 0;
    index->fsync_disable =
        (flags & MAIL_INDEX_OPEN_FLAG_FSYNC_DISABLE) != 0;
    index->nfs_flush = (flags & MAIL_INDEX_OPEN_FLAG_NFS_FLUSH) != 0;
    index->lock_method = lock_method;

    if (index->nfs_flush && index->fsync_disable)
        i_fatal("nfs flush requires fsync_disable=no");
    if (index->nfs_flush && !index->mmap_disable)
        i_fatal("nfs flush requires mmap_disable=yes");

    if ((ret = mail_index_open_files(index, flags)) <= 0) {
        /* doesn't exist and create flag not used */
        mail_index_close(index);
        return ret;
    }

    i_assert(index->map != NULL);
    index->opened = TRUE;
    return 1;
}

static void mail_index_close_file(struct mail_index *index)
{
    if (index->file_lock != NULL)
        file_lock_free(&index->file_lock);

    if (index->fd != -1) {
        if (close(index->fd) < 0)
            mail_index_set_syscall_error(index, "close()");
        index->fd = -1;
    }

    index->lock_id_counter += 2;
    index->lock_type = F_UNLCK;
    index->shared_lock_count = 0;
    index->excl_lock_count = 0;
}

void mail_index_close(struct mail_index *index)
{
    if (index->map != NULL)
        mail_index_unmap(&index->map);

    mail_index_close_file(index);
    mail_transaction_log_close(index->log);
    if (index->cache != NULL)
        mail_cache_free(&index->cache);

    i_free_and_null(index->filepath);

    index->indexid = 0;
    index->opened = FALSE;
}

int mail_index_reopen_if_changed(struct mail_index *index)
{
    struct stat st1, st2;

    i_assert(index->excl_lock_count == 0);

    if (MAIL_INDEX_IS_IN_MEMORY(index))
        return 0;

    if (index->fd == -1)
        return mail_index_try_open_only(index);

    if (fstat(index->fd, &st1) < 0) {
        if (errno != ESTALE)
            return mail_index_set_syscall_error(index, "fstat()");
        /* deleted/recreated, reopen */
        mail_index_close_file(index);
        return mail_index_try_open_only(index);
    }

    if (index->nfs_flush)
        nfs_flush_attr_cache(index->filepath);
    if (nfs_safe_stat(index->filepath, &st2) < 0) {
        if (errno == ENOENT)
            return 0;

        return mail_index_set_syscall_error(index, "stat()");
    }

    if (st1.st_ino == st2.st_ino && CMP_DEV_T(st1.st_dev, st2.st_dev)) {
        /* the same file */
        return 1;
    }

    /* new file, new locks. the old fd can keep its locks, they don't
       matter anymore as no-one's going to modify the file. */
    mail_index_close_file(index);

    return mail_index_try_open_only(index);
}

int mail_index_refresh(struct mail_index *index)
{
    int ret;

    if (MAIL_INDEX_IS_IN_MEMORY(index))
        return 0;

    if (index->excl_lock_count > 0) {
        /* we have index exclusively locked, nothing could
           have changed. */
        return 0;
    }

    ret = mail_index_map(index, MAIL_INDEX_SYNC_HANDLER_HEAD);
    return ret <= 0 ? -1 : 0;
}

struct mail_cache *mail_index_get_cache(struct mail_index *index)
{
    return index->cache;
}

int mail_index_set_error(struct mail_index *index, const char *fmt, ...)
{
    va_list va;

    i_free(index->error);

    if (fmt == NULL)
        index->error = NULL;
    else {
        va_start(va, fmt);
        index->error = i_strdup_vprintf(fmt, va);
        va_end(va);

        i_error("%s", index->error);
    }

    return -1;
}

int mail_index_move_to_memory(struct mail_index *index)
{
    struct mail_index_map *map;

    if (MAIL_INDEX_IS_IN_MEMORY(index))
        return index->map == NULL ? -1 : 0;

    /* set the index as being into memory */
    i_free_and_null(index->dir);

    i_free(index->filepath);
    index->filepath = i_strdup("(in-memory index)");

    if (index->map == NULL) {
        /* index was never even opened. just mark it as being in
           memory and let the caller re-open the index. */
        i_assert(index->fd == -1);
        return -1;
    }

    /* move index map to memory */
    if (!MAIL_INDEX_MAP_IS_IN_MEMORY(index->map)) {
        map = mail_index_map_clone(index->map);
        mail_index_unmap(&index->map);
        index->map = map;
    }

    if (index->log != NULL) {
        /* move transaction log to memory */
        mail_transaction_log_move_to_memory(index->log);
    }

    if (index->file_lock != NULL)
        file_lock_free(&index->file_lock);

    if (index->fd != -1) {
        if (close(index->fd) < 0)
            mail_index_set_syscall_error(index, "close()");
        index->fd = -1;
    }
    return 0;
}

void mail_index_mark_corrupted(struct mail_index *index)
{
    index->indexid = 0;

    index->map->hdr.flags |= MAIL_INDEX_HDR_FLAG_CORRUPTED;
    if (unlink(index->filepath) < 0 && errno != ENOENT && errno != ESTALE)
        mail_index_set_syscall_error(index, "unlink()");
}

int mail_index_set_syscall_error(struct mail_index *index,
                 const char *function)
{
    i_assert(function != NULL);

    if (ENOSPACE(errno)) {
        index->nodiskspace = TRUE;
        return -1;
    }

    return mail_index_set_error(index, "%s failed with index file %s: %m",
                    function, index->filepath);
}

int mail_index_file_set_syscall_error(struct mail_index *index,
                      const char *filepath,
                      const char *function)
{
    i_assert(filepath != NULL);
    i_assert(function != NULL);

    if (ENOSPACE(errno)) {
        index->nodiskspace = TRUE;
        return -1;
    }

    return mail_index_set_error(index, "%s failed with file %s: %m",
                    function, filepath);
}

const char *mail_index_get_error_message(struct mail_index *index)
{
    return index->error;
}

void mail_index_reset_error(struct mail_index *index)
{
    if (index->error != NULL) {
        i_free(index->error);
        index->error = NULL;
    }

    index->nodiskspace = FALSE;
        index->index_lock_timeout = FALSE;
}

#ifdef WORDS_BIGENDIAN
/* FIXME: Unfortunately these functions were originally written to use
   endian-specific code and we can't avoid that without breaking backwards
   compatibility. When we do break it, just select one of these. */
uint32_t mail_index_uint32_to_offset(uint32_t offset)
{
    i_assert(offset < 0x40000000);
    i_assert((offset & 3) == 0);

    offset >>= 2;
    return  0x00000080 | ((offset & 0x0000007f)) |
        0x00008000 | ((offset & 0x00003f80) >> 7 << 8) |
        0x00800000 | ((offset & 0x001fc000) >> 14 << 16) |
        0x80000000 | ((offset & 0x0fe00000) >> 21 << 24);
}

uint32_t mail_index_offset_to_uint32(uint32_t offset)
{
    if ((offset & 0x80808080) != 0x80808080)
        return 0;

    return  (((offset & 0x0000007f)) |
         ((offset & 0x00007f00) >> 8 << 7) |
         ((offset & 0x007f0000) >> 16 << 14) |
         ((offset & 0x7f000000) >> 24 << 21)) << 2;
}
#else
uint32_t mail_index_uint32_to_offset(uint32_t offset)
{
    i_assert(offset < 0x40000000);
    i_assert((offset & 3) == 0);

    offset >>= 2;
    return  0x80000000 | ((offset & 0x0000007f) << 24) |
        0x00800000 | ((offset & 0x00003f80) >> 7 << 16) |
        0x00008000 | ((offset & 0x001fc000) >> 14 << 8) |
        0x00000080 | ((offset & 0x0fe00000) >> 21);
}

uint32_t mail_index_offset_to_uint32(uint32_t offset)
{
    if ((offset & 0x80808080) != 0x80808080)
        return 0;

    return  (((offset & 0x0000007f) << 21) |
         ((offset & 0x00007f00) >> 8 << 14) |
         ((offset & 0x007f0000) >> 16 << 7) |
         ((offset & 0x7f000000) >> 24)) << 2;
}
#endif