index/shared/shared-storage.c

	shared-storage.c revision 3398d5e2b883812de5d569721c8294b581e1d9e6
/* Copyright (c) 2008 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "array.h"
#include "str.h"
#include "ioloop.h"
#include "auth-master.h"
#include "var-expand.h"
#include "index-storage.h"
#include "shared-storage.h"

#include <stdlib.h>
#include <ctype.h>

#define SHARED_LIST_CONTEXT(obj) \
    MODULE_CONTEXT(obj, shared_mailbox_list_module)

extern struct mail_storage shared_storage;
extern struct mailbox shared_mailbox;

static MODULE_CONTEXT_DEFINE_INIT(shared_mailbox_list_module,
                  &mailbox_list_module_register);

static struct mail_storage *shared_alloc(void)
{
    struct shared_storage *storage;
    pool_t pool;

    pool = pool_alloconly_create("shared storage", 256);
    storage = p_new(pool, struct shared_storage, 1);
    storage->storage = shared_storage;
    storage->storage.pool = pool;
    storage->storage.storage_class = &shared_storage;

    storage->base_dir = p_strdup(pool, getenv("BASE_DIR"));
    if (storage->base_dir == NULL)
        storage->base_dir = PKG_RUNDIR;

    return &storage->storage;
}

static int shared_create(struct mail_storage *_storage, const char *data,
             const char **error_r)
{
    struct shared_storage *storage = (struct shared_storage *)_storage;
    struct mailbox_list_settings list_set;
    const char *driver, *p;
    char *wildcardp;
    bool have_username;

    /* data must begin with the actual mailbox driver */
    p = strchr(data, ':');
    if (p == NULL) {
        *error_r = "Shared mailbox location not prefixed with driver";
        return -1;
    }
    driver = t_strdup_until(data, p);
    storage->location = p_strdup(_storage->pool, data);
    storage->storage_class = mail_storage_find_class(driver);
    if (storage->storage_class == NULL) {
        *error_r = t_strconcat("Unknown shared storage driver: ",
                       driver, NULL);
        return -1;
    }
    _storage->mailbox_is_file = storage->storage_class->mailbox_is_file;

    wildcardp = strchr(_storage->ns->prefix, '%');
    if (wildcardp == NULL) {
        *error_r = "Shared namespace prefix doesn't contain %";
        return -1;
    }
    storage->ns_prefix_pattern = p_strdup(_storage->pool, wildcardp);
    *wildcardp = '\0';

    have_username = FALSE;
    for (p = storage->ns_prefix_pattern; *p != '\0'; p++) {
        if (*p != '%')
            continue;
        if (*++p == '\0')
            break;
        if (*p == 'u' || *p == 'n')
            have_username = TRUE;
        else if (*p != 'd')
            break;
    }
    if (*p != '\0') {
        *error_r = "Shared namespace prefix contains unknown variables";
        return -1;
    }
    if (!have_username) {
        *error_r = "Shared namespace prefix doesn't contain %u or %n";
        return -1;
    }

    if (mailbox_list_alloc("shared", &_storage->list, error_r) < 0)
        return -1;
    MODULE_CONTEXT_SET_FULL(_storage->list, shared_mailbox_list_module,
                storage, &storage->list_module_ctx);

    memset(&list_set, 0, sizeof(list_set));
    list_set.mail_storage_flags = &_storage->flags;
    list_set.lock_method = &_storage->lock_method;
    mailbox_list_init(_storage->list, _storage->ns, &list_set,
              mail_storage_get_list_flags(_storage->flags));
    return 0;
}

static void shared_storage_destroy(struct mail_storage *_storage)
{
    struct shared_storage *storage = (struct shared_storage *)_storage;

    if (storage->auth_master_conn != NULL)
        auth_master_deinit(&storage->auth_master_conn);
    index_storage_destroy(_storage);
}

static void shared_storage_auth_master_init(struct shared_storage *storage)
{
    const char *auth_socket_path;
    bool debug;

    auth_socket_path = getenv("AUTH_SOCKET_PATH");
    if (auth_socket_path == NULL) {
        auth_socket_path = t_strconcat(storage->base_dir,
                           "/auth-master", NULL);
    }

    debug = (storage->storage.flags & MAIL_STORAGE_FLAG_DEBUG) != 0;
    storage->auth_master_conn = auth_master_init(auth_socket_path, debug);
}

static int
shared_storage_lookup_home(struct shared_storage *storage,
               const char *user, const char **home_r)
{
    struct auth_user_reply reply;
    pool_t userdb_pool;
    int ret;

    if (storage->auth_master_conn == NULL)
        shared_storage_auth_master_init(storage);

    userdb_pool = pool_alloconly_create("userdb lookup", 512);
    ret = auth_master_user_lookup(storage->auth_master_conn, user,
                      AUTH_SERVICE_INTERNAL,
                      userdb_pool, &reply);
    if (ret > 0)
        *home_r = t_strdup(reply.home);
    pool_unref(&userdb_pool);
    return ret;
}

static void get_nonexisting_user_location(struct shared_storage *storage,
                      string_t *location)
{
    /* user wasn't found. we'll still need to create the storage
       to avoid exposing which users exist and which don't. */
    str_append(location, storage->storage_class->name);
    str_append_c(location, ':');

    /* use a reachable but non-existing path as the mail root directory */
    str_append(location, storage->base_dir);
    str_append(location, PKG_RUNDIR"/user-not-found");
}

int shared_storage_get_namespace(struct mail_storage *_storage,
                 const char **_name,
                 struct mail_namespace **ns_r)
{
    struct shared_storage *storage = (struct shared_storage *)_storage;
    struct mail_user *user = _storage->ns->user;
    static struct var_expand_table static_tab[] = {
        { 'u', NULL },
        { 'n', NULL },
        { 'd', NULL },
        { 'h', NULL },
        { '\0', NULL }
    };
    struct var_expand_table *tab;
    struct mail_namespace *ns;
    const char *domain = NULL, *username = NULL, *userdomain = NULL;
    const char *name, *p, *next, **dest, *error;
    string_t *prefix, *location;
    int ret;

    *ns_r = NULL;

    p = storage->ns_prefix_pattern;
    for (name = *_name; *p != '\0';) {
        if (*p != '%') {
            if (*p != *name)
                return -1;
            p++; name++;
            continue;
        }
        switch (*++p) {
        case 'd':
            dest = &domain;
            break;
        case 'n':
            dest = &username;
            break;
        case 'u':
            dest = &userdomain;
            break;
        default:
            /* we checked this already above */
            i_unreached();
        }
        p++;

        next = strchr(name, *p != '\0' ? *p : _storage->ns->sep);
        if (next == NULL)
            return -1;

        *dest = t_strdup_until(name, next);
        name = next;
    }
    /* successfully matched the name. */
    if (userdomain == NULL) {
        i_assert(username != NULL);
        userdomain = domain == NULL ? username :
            t_strconcat(username, "@", domain, NULL);
    } else {
        domain = strchr(userdomain, '@');
        if (domain == NULL)
            username = userdomain;
        else {
            username = t_strdup_until(userdomain, domain);
            domain++;
        }
    }

    /* expand the namespace prefix and see if it already exists.
       this should normally happen only when the mailbox is being opened */
    tab = t_malloc(sizeof(static_tab));
    memcpy(tab, static_tab, sizeof(static_tab));
    tab[0].value = userdomain;
    tab[1].value = username;
    tab[2].value = domain;

    prefix = t_str_new(128);
    str_append(prefix, _storage->ns->prefix);
    var_expand(prefix, storage->ns_prefix_pattern, tab);

    ns = mail_namespace_find_prefix(user->namespaces, str_c(prefix));
    if (ns != NULL) {
        *_name = mail_namespace_fix_sep(ns, name);
        *ns_r = ns;
        return 0;
    }

    if (!var_has_key(storage->location, 'h'))
        ret = 1;
    else {
        /* we'll need to look up the user's home directory */
        ret = shared_storage_lookup_home(storage, userdomain,
                         &tab[3].value);
        if (ret < 0) {
            mail_storage_set_critical(_storage, "Namespace '%s': "
                "Could not lookup home for user %s",
                _storage->ns->prefix, userdomain);
            return -1;
        }
    }

    /* create the new namespace */
    ns = i_new(struct mail_namespace, 1);
    ns->type = NAMESPACE_SHARED;
    ns->user = user;
    ns->prefix = i_strdup(str_c(prefix));
    ns->flags = NAMESPACE_FLAG_LIST | NAMESPACE_FLAG_HIDDEN |
        NAMESPACE_FLAG_AUTOCREATED;
    ns->sep = _storage->ns->sep;

    location = t_str_new(256);
    if (ret > 0)
        var_expand(location, storage->location, tab);
    else
        get_nonexisting_user_location(storage, location);
    if (mail_storage_create(ns, NULL, str_c(location), _storage->flags,
                _storage->lock_method, &error) < 0) {
        mail_storage_set_critical(_storage, "Namespace '%s': %s",
                      ns->prefix, error);
        return -1;
    }
    mail_user_add_namespace(user, ns);

    *_name = mail_namespace_fix_sep(ns, name);
    *ns_r = ns;
    return 0;
}

static void shared_mailbox_copy_error(struct mail_storage *shared_storage,
                      struct mail_namespace *backend_ns)
{
    const char *str;
    enum mail_error error;

    str = mail_storage_get_last_error(backend_ns->storage, &error);
    mail_storage_set_error(shared_storage, error, str);
}

static struct mailbox *
shared_mailbox_open(struct mail_storage *storage, const char *name,
            struct istream *input, enum mailbox_open_flags flags)
{
    struct mail_namespace *ns;
    struct mailbox *box;

    if (input != NULL) {
        mail_storage_set_critical(storage,
            "Shared storage doesn't support streamed mailboxes");
        return NULL;
    }

    if (shared_storage_get_namespace(storage, &name, &ns) < 0)
        return NULL;

    /* if we call the normal mailbox_open() here the plugins will see
       mailbox_open() called twice and they could break. */
    box = ns->storage->storage_class->v.
        mailbox_open(ns->storage, name, NULL, flags);
    if (box == NULL)
        shared_mailbox_copy_error(storage, ns);
    else
        ns->flags |= NAMESPACE_FLAG_USABLE;
    return box;
}

static int shared_mailbox_create(struct mail_storage *storage,
                 const char *name, bool directory)
{
    struct mail_namespace *ns;
    int ret;

    if (shared_storage_get_namespace(storage, &name, &ns) < 0)
        return -1;

    ret = mail_storage_mailbox_create(ns->storage, name, directory);
    if (ret < 0)
        shared_mailbox_copy_error(storage, ns);
    return ret;
}

struct mail_storage shared_storage = {
    MEMBER(name) SHARED_STORAGE_NAME,
    MEMBER(mailbox_is_file) FALSE, /* unknown at this point */

    {
        NULL,
        NULL,
        shared_alloc,
        shared_create,
        shared_storage_destroy,
        NULL,
        shared_mailbox_open,
        shared_mailbox_create
    }
};