index/maildir/maildir-keywords.c

	maildir-keywords.c revision 6e1e9e341ffe21a69a23229c2b896d03066a071e
248N/A/* Copyright (C) 2005 Timo Sirainen */
248N/A
248N/A/* note that everything here depends on uidlist file being locked the whole
248N/A   time. that's why we don't have any locking of our own, or that we do things
248N/A   that would be racy otherwise. */
248N/A
248N/A#include "lib.h"
248N/A#include "array.h"
248N/A#include "ioloop.h"
248N/A#include "hash.h"
248N/A#include "str.h"
248N/A#include "istream.h"
248N/A#include "file-dotlock.h"
248N/A#include "write-full.h"
248N/A#include "maildir-storage.h"
248N/A#include "maildir-uidlist.h"
248N/A#include "maildir-keywords.h"
248N/A
248N/A#include <stdlib.h>
248N/A#include <sys/stat.h>
248N/A#include <utime.h>
248N/A
2490N/A/* how many seconds to wait before overriding dovecot-keywords.lock */
248N/A#define KEYWORDS_LOCK_STALE_TIMEOUT (60*2)
248N/A
814N/Astruct maildir_keywords {
814N/A    struct maildir_mailbox *mbox;
2238N/A    char *path;
814N/A
248N/A    pool_t pool;
248N/A    ARRAY_TYPE(keywords) list;
248N/A    struct hash_table *hash; /* name -> idx+1 */
248N/A
248N/A        struct dotlock_settings dotlock_settings;
248N/A
248N/A    time_t synced_mtime;
844N/A    unsigned int synced:1;
844N/A    unsigned int changed:1;
248N/A};
1273N/A
248N/Astruct maildir_keywords_sync_ctx {
248N/A    struct maildir_keywords *mk;
248N/A    struct mail_index *index;
248N/A
248N/A    const ARRAY_TYPE(keywords) *keywords;
248N/A    ARRAY_DEFINE(idx_to_chr, char);
248N/A    unsigned int chridx_to_idx[MAILDIR_MAX_KEYWORDS];
248N/A};
248N/A
248N/Astruct maildir_keywords *maildir_keywords_init(struct maildir_mailbox *mbox)
690N/A{
248N/A    struct maildir_keywords *mk;
248N/A
690N/A    mk = i_new(struct maildir_keywords, 1);
248N/A    mk->mbox = mbox;
248N/A    mk->path = i_strconcat(mbox->control_dir,
248N/A                   "/" MAILDIR_KEYWORDS_NAME, NULL);
248N/A    mk->pool = pool_alloconly_create("maildir keywords", 256);
248N/A    i_array_init(&mk->list, MAILDIR_MAX_KEYWORDS);
248N/A    mk->hash = hash_create(default_pool, mk->pool, 0,
248N/A                   strcase_hash, (hash_cmp_callback_t *)strcasecmp);
248N/A
248N/A    mk->dotlock_settings.use_excl_lock =
248N/A        (STORAGE(mbox->storage)->flags &
248N/A         MAIL_STORAGE_FLAG_DOTLOCK_USE_EXCL) != 0;
248N/A    mk->dotlock_settings.timeout = KEYWORDS_LOCK_STALE_TIMEOUT + 2;
248N/A    mk->dotlock_settings.stale_timeout = KEYWORDS_LOCK_STALE_TIMEOUT;
248N/A    mk->dotlock_settings.temp_prefix = mbox->storage->temp_prefix;
248N/A    return mk;
248N/A}
248N/A
2490N/Avoid maildir_keywords_deinit(struct maildir_keywords *mk)
248N/A{
248N/A    hash_destroy(mk->hash);
248N/A    array_free(&mk->list);
248N/A    pool_unref(mk->pool);
248N/A    i_free(mk->path);
248N/A    i_free(mk);
248N/A}
248N/A
248N/Astatic void maildir_keywords_clear(struct maildir_keywords *mk)
248N/A{
248N/A    array_clear(&mk->list);
    hash_clear(mk->hash, FALSE);
    p_clear(mk->pool);
}

static int maildir_keywords_sync(struct maildir_keywords *mk)
{
    struct istream *input;
    struct stat st;
    char *line, *p, *new_name;
    const char **strp;
    int fd, idx;

        /* Remember that we rely on uidlist file locking in here. That's why
           we rely on stat()'s timestamp and don't bother handling ESTALE
           errors. */

    if (stat(mk->path, &st) < 0) {
        if (errno == ENOENT) {
            maildir_keywords_clear(mk);
            mk->synced = TRUE;
            return 0;
        }
                mail_storage_set_critical(STORAGE(mk->mbox->storage),
                      "stat(%s) failed: %m", mk->path);
        return -1;
    }

    if (st.st_mtime == mk->synced_mtime) {
        /* hasn't changed */
        mk->synced = TRUE;
        return 0;
    }
    mk->synced_mtime = st.st_mtime;

    fd = open(mk->path, O_RDONLY);
    if (fd == -1) {
        if (errno == ENOENT) {
            maildir_keywords_clear(mk);
            mk->synced = TRUE;
            return 0;
        }
                mail_storage_set_critical(STORAGE(mk->mbox->storage),
                      "open(%s) failed: %m", mk->path);
        return -1;
    }

    maildir_keywords_clear(mk);
    input = i_stream_create_file(fd, default_pool, 1024, FALSE);
    while ((line = i_stream_read_next_line(input)) != NULL) {
        p = strchr(line, ' ');
        if (p == NULL) {
            /* note that when converting .customflags file this
               case happens in the first line. */
            continue;
        }
        *p++ = '\0';

        idx = atoi(line);
        if (idx < 0 || idx >= MAILDIR_MAX_KEYWORDS) {
            /* shouldn't happen */
            continue;
        }

        /* save it */
        new_name = p_strdup(mk->pool, p);
        hash_insert(mk->hash, new_name, POINTER_CAST(idx + 1));

        strp = array_idx_modifiable(&mk->list, idx);
        *strp = new_name;
    }
    i_stream_destroy(&input);

    if (close(fd) < 0) {
                mail_storage_set_critical(STORAGE(mk->mbox->storage),
                      "close(%s) failed: %m", mk->path);
        return -1;
    }

    mk->synced = TRUE;
    return 0;
}

static int
maildir_keywords_lookup(struct maildir_keywords *mk, const char *name)
{
    void *p;

    i_assert(maildir_uidlist_is_locked(mk->mbox->uidlist));

    p = hash_lookup(mk->hash, name);
    if (p == NULL) {
        if (mk->synced)
            return -1;

        if (maildir_keywords_sync(mk) < 0)
            return -1;

        p = hash_lookup(mk->hash, name);
        if (p == NULL)
            return -1;
    }

    return POINTER_CAST_TO(p, int)-1;
}

static void
maildir_keywords_create(struct maildir_keywords *mk, const char *name,
            unsigned int chridx)
{
    const char **strp;
    char *new_name;

    i_assert(chridx < MAILDIR_MAX_KEYWORDS);

    new_name = p_strdup(mk->pool, name);
    hash_insert(mk->hash, new_name, POINTER_CAST(chridx + 1));

    strp = array_idx_modifiable(&mk->list, chridx);
    *strp = new_name;

    mk->changed = TRUE;
}

static int
maildir_keywords_lookup_or_create(struct maildir_keywords *mk, const char *name)
{
    const char *const *keywords;
    unsigned int i, count;
    int idx;

    idx = maildir_keywords_lookup(mk, name);
    if (idx >= 0)
        return idx;
    if (!mk->synced) {
        /* we couldn't open the dovecot-keywords file. */
        return -1;
    }

    /* see if we are full */
    keywords = array_get(&mk->list, &count);
    for (i = 0; i < count; i++) {
        if (keywords[i] == NULL)
            break;
    }

    if (i == count && count >= MAILDIR_MAX_KEYWORDS)
        return -1;

        maildir_keywords_create(mk, name, i);
    return i;
}

static const char *
maildir_keywords_idx(struct maildir_keywords *mk, unsigned int idx)
{
    const char *const *keywords;
    unsigned int count;

    i_assert(maildir_uidlist_is_locked(mk->mbox->uidlist));

    keywords = array_get(&mk->list, &count);
    if (idx >= count) {
        if (mk->synced)
            return NULL;

        if (maildir_keywords_sync(mk) < 0)
            return NULL;

        keywords = array_get(&mk->list, &count);
    }
    return idx >= count ? NULL : keywords[idx];
}

static int maildir_keywords_commit(struct maildir_keywords *mk)
{
    struct dotlock *dotlock;
    const char *lock_path, *const *keywords;
    unsigned int i, count;
    struct utimbuf ut;
    string_t *str;
    mode_t old_mask;
    int fd;

    mk->synced = FALSE;

    if (!mk->changed)
        return 0;

    /* we could just create the temp file directly, but doing it this
       ways avoids potential problems with overwriting contents in
       malicious symlinks */
    t_push();
    lock_path = t_strconcat(mk->path, ".lock", NULL);
    (void)unlink(lock_path);
        old_mask = umask(0777 & ~mk->mbox->mail_create_mode);
    fd = file_dotlock_open(&mk->dotlock_settings, mk->path,
                   DOTLOCK_CREATE_FLAG_NONBLOCK, &dotlock);
    umask(old_mask);
    if (fd == -1) {
        mail_storage_set_critical(STORAGE(mk->mbox->storage),
            "file_dotlock_open(%s) failed: %m", mk->path);
        t_pop();
        return -1;
    }

    str = t_str_new(256);
    keywords = array_get(&mk->list, &count);
    for (i = 0; i < count; i++) {
        if (keywords[i] != NULL)
            str_printfa(str, "%u %s\n", i, keywords[i]);
    }
    if (write_full(fd, str_data(str), str_len(str)) < 0) {
        mail_storage_set_critical(STORAGE(mk->mbox->storage),
            "write_full(%s) failed: %m", mk->path);
        (void)file_dotlock_delete(&dotlock);
        t_pop();
        return -1;
    }

    /* mtime must grow every time */
        mk->synced_mtime = ioloop_time <= mk->synced_mtime ?
        mk->synced_mtime + 1 : ioloop_time;
    ut.actime = ioloop_time;
    ut.modtime = mk->synced_mtime;
    if (utime(lock_path, &ut) < 0) {
        mail_storage_set_critical(STORAGE(mk->mbox->storage),
            "utime(%s) failed: %m", lock_path);
        return -1;
    }

    if (file_dotlock_replace(&dotlock, 0) < 0) {
        mail_storage_set_critical(STORAGE(mk->mbox->storage),
            "file_dotlock_replace(%s) failed: %m", mk->path);
        t_pop();
        return -1;
    }

    mk->changed = FALSE;
    t_pop();
    return 0;
}

struct maildir_keywords_sync_ctx *
maildir_keywords_sync_init(struct maildir_keywords *mk,
               struct mail_index *index)
{
    struct maildir_keywords_sync_ctx *ctx;

    ctx = i_new(struct maildir_keywords_sync_ctx, 1);
    ctx->mk = mk;
    ctx->index = index;
    ctx->keywords = mail_index_get_keywords(index);
    i_array_init(&ctx->idx_to_chr, MAILDIR_MAX_KEYWORDS);
    return ctx;
}

void maildir_keywords_sync_deinit(struct maildir_keywords_sync_ctx *ctx)
{
    maildir_keywords_commit(ctx->mk);
    array_free(&ctx->idx_to_chr);
    i_free(ctx);
}

unsigned int maildir_keywords_char_idx(struct maildir_keywords_sync_ctx *ctx,
                       char keyword)
{
    const char *name;
    unsigned int chridx, idx;

    i_assert(keyword >= MAILDIR_KEYWORD_FIRST &&
         keyword <= MAILDIR_KEYWORD_LAST);
    chridx = keyword - MAILDIR_KEYWORD_FIRST;

    if (ctx->chridx_to_idx[chridx] != 0)
        return ctx->chridx_to_idx[chridx];

    /* lookup / create */
    name = maildir_keywords_idx(ctx->mk, chridx);
    if (name == NULL) {
        /* name is lost. just generate one ourself. */
        name = t_strdup_printf("unknown-%u", chridx);
        while (maildir_keywords_lookup(ctx->mk, name) >= 0) {
            /* don't create a duplicate name.
               keep changing the name until it doesn't exist */
            name = t_strconcat(name, "?", NULL);
        }
                maildir_keywords_create(ctx->mk, name, chridx);
    }

    if (!mail_index_keyword_lookup(ctx->index, name, TRUE, &idx))
        i_unreached();

        ctx->chridx_to_idx[chridx] = idx;
    return idx;
}

char maildir_keywords_idx_char(struct maildir_keywords_sync_ctx *ctx,
                   unsigned int idx)
{
    const char *const *name_p;
    char *chr_p;
    int chridx;

    chr_p = array_idx_modifiable(&ctx->idx_to_chr, idx);
    if (*chr_p != '\0')
        return *chr_p;

    name_p = array_idx(ctx->keywords, idx);
    chridx = maildir_keywords_lookup_or_create(ctx->mk, *name_p);
    if (chridx < 0)
        return '\0';

    *chr_p = chridx + MAILDIR_KEYWORD_FIRST;
    return *chr_p;
}