src/imap/cmd-copy.c

/* Copyright (c) 2002-2018 Dovecot authors, see the included COPYING file */

#include "imap-common.h"
#include "str.h"
#include "ostream.h"
#include "imap-resp-code.h"
#include "imap-util.h"
#include "imap-commands.h"
#include "imap-search-args.h"

#include <time.h>

#define COPY_CHECK_INTERVAL 100

static void client_send_sendalive_if_needed(struct client *client)
{
    time_t now, last_io;

    if (o_stream_get_buffer_used_size(client->output) != 0)
        return;

    now = time(NULL);
    last_io = I_MAX(client->last_input, client->last_output);
    if (now - last_io > MAIL_STORAGE_STAYALIVE_SECS) {
        o_stream_nsend_str(client->output, "* OK Hang in there..\r\n");
        /* make sure it doesn't get stuck on the corked stream */
        o_stream_uncork(client->output);
        o_stream_cork(client->output);
        client->last_output = now;
    }
}

static int fetch_and_copy(struct client_command_context *cmd, bool move,
              struct mailbox_transaction_context *t,
              struct mailbox_transaction_context **src_trans_r,
              struct mail_search_args *search_args,
              const char **src_uidset_r,
              unsigned int *copy_count_r)
{
    struct client *client = cmd->client;
    struct mail_search_context *search_ctx;
        struct mailbox_transaction_context *src_trans;
    struct mail_save_context *save_ctx;
    struct mail *mail;
    unsigned int copy_count = 0;
    struct msgset_generator_context srcset_ctx;
    string_t *src_uidset;
    int ret;

    i_assert(o_stream_is_corked(client->output));

    src_uidset = t_str_new(256);
    msgset_generator_init(&srcset_ctx, src_uidset);

    src_trans = mailbox_transaction_begin(client->mailbox, 0,
                          imap_client_command_get_reason(cmd));
    search_ctx = mailbox_search_init(src_trans, search_args, NULL, 0, NULL);

    ret = 1;
    while (mailbox_search_next(search_ctx, &mail) && ret > 0) {
        if (mail->expunged) {
            ret = 0;
            break;
        }

        if ((++copy_count % COPY_CHECK_INTERVAL) == 0)
            client_send_sendalive_if_needed(client);

        save_ctx = mailbox_save_alloc(t);
        mailbox_save_copy_flags(save_ctx, mail);

        if (move) {
            if (mailbox_move(&save_ctx, mail) < 0)
                ret = -1;
        } else {
            if (mailbox_copy(&save_ctx, mail) < 0)
                ret = -1;
        }
        if (ret < 0 && mail->expunged)
            ret = 0;

        msgset_generator_next(&srcset_ctx, mail->uid);
    }
    msgset_generator_finish(&srcset_ctx);

    if (mailbox_search_deinit(&search_ctx) < 0)
        ret = -1;

    *src_trans_r = src_trans;
    *src_uidset_r = str_c(src_uidset);
    *copy_count_r = copy_count;
    return ret;
}

static void copy_update_trashed(struct client *client, struct mailbox *box,
                unsigned int count)
{
    const struct mailbox_settings *set;

    set = mailbox_settings_find(mailbox_get_namespace(box),
                    mailbox_get_vname(box));
    if (set != NULL && set->special_use[0] != '\0' &&
        str_array_icase_find(t_strsplit_spaces(set->special_use, " "),
                 "\\Trash"))
        client->trashed_count += count;
}

static bool cmd_copy_full(struct client_command_context *cmd, bool move)
{
    struct client *client = cmd->client;
    struct mail_storage *dest_storage;
    struct mailbox *destbox;
    struct mailbox_transaction_context *t, *src_trans;
        struct mail_search_args *search_args;
    const char *messageset, *mailbox, *src_uidset;
    enum mailbox_sync_flags sync_flags = 0;
    enum imap_sync_flags imap_flags = 0;
    struct mail_transaction_commit_changes changes;
    unsigned int copy_count;
    string_t *msg;
    int ret;

    /* <message set> <mailbox> */
    if (!client_read_string_args(cmd, 2, &messageset, &mailbox))
        return FALSE;

    if (!client_verify_open_mailbox(cmd))
        return TRUE;

    ret = imap_search_get_seqset(cmd, messageset, cmd->uid, &search_args);
    if (ret <= 0)
        return ret < 0;

    if (client_open_save_dest_box(cmd, mailbox, &destbox) < 0) {
        mail_search_args_unref(&search_args);
        return TRUE;
    }

    t = mailbox_transaction_begin(destbox,
                      MAILBOX_TRANSACTION_FLAG_EXTERNAL |
                      MAILBOX_TRANSACTION_FLAG_ASSIGN_UIDS,
                      imap_client_command_get_reason(cmd));
    ret = fetch_and_copy(cmd, move, t, &src_trans, search_args,
                 &src_uidset, &copy_count);
    mail_search_args_unref(&search_args);

    msg = t_str_new(256);
    if (ret <= 0)
        mailbox_transaction_rollback(&t);
    else if (mailbox_transaction_commit_get_changes(&t, &changes) < 0) {
        if (mailbox_get_last_mail_error(destbox) == MAIL_ERROR_EXPUNGED) {
            /* storage backend didn't notice the expunge until
               at commit time. */
            ret = 0;
        } else {
            ret = -1;
        }
    } else if (copy_count == 0) {
        str_append(msg, "OK No messages found.");
        pool_unref(&changes.pool);
    } else if (seq_range_count(&changes.saved_uids) == 0 ||
           changes.no_read_perm) {
        /* not supported by backend (virtual) or no read permissions
           for mailbox */
        str_append(msg, move ? "OK Move completed." :
               "OK Copy completed.");
        pool_unref(&changes.pool);
    } else if (move) {
        i_assert(copy_count == seq_range_count(&changes.saved_uids));
        copy_update_trashed(client, destbox, copy_count);

        str_printfa(msg, "* OK [COPYUID %u %s ",
                changes.uid_validity, src_uidset);
        imap_write_seq_range(msg, &changes.saved_uids);
        str_append(msg, "] Moved UIDs.");
        client_send_line(client, str_c(msg));

        str_truncate(msg, 0);
        str_append(msg, "OK Move completed.");
        pool_unref(&changes.pool);
    } else {
        i_assert(copy_count == seq_range_count(&changes.saved_uids));
        copy_update_trashed(client, destbox, copy_count);

        str_printfa(msg, "OK [COPYUID %u %s ", changes.uid_validity,
                src_uidset);
        imap_write_seq_range(msg, &changes.saved_uids);
        str_append(msg, "] Copy completed.");
        pool_unref(&changes.pool);
    }

    if (ret <= 0 && move) {
        /* move failed, don't expunge anything */
        mailbox_transaction_rollback(&src_trans);
    } else {
        if (mailbox_transaction_commit(&src_trans) < 0)
            ret = -1;
    }

    dest_storage = mailbox_get_storage(destbox);
    if (destbox != client->mailbox) {
        if (move)
            sync_flags |= MAILBOX_SYNC_FLAG_EXPUNGE;
        else
            sync_flags |= MAILBOX_SYNC_FLAG_FAST;
        imap_flags |= IMAP_SYNC_FLAG_SAFE;
        mailbox_free(&destbox);
    } else if (move) {
        sync_flags |= MAILBOX_SYNC_FLAG_EXPUNGE;
        imap_flags |= IMAP_SYNC_FLAG_SAFE;
    }

    if (ret > 0)
        return cmd_sync(cmd, sync_flags, imap_flags, str_c(msg));
    else if (ret == 0) {
        /* some messages were expunged, sync them */
        return cmd_sync(cmd, 0, 0,
            "NO ["IMAP_RESP_CODE_EXPUNGEISSUED"] "
            "Some of the requested messages no longer exist.");
    } else {
        client_send_storage_error(cmd, dest_storage);
        return TRUE;
    }
}

bool cmd_copy(struct client_command_context *cmd)
{
    return cmd_copy_full(cmd, FALSE);
}

bool cmd_move(struct client_command_context *cmd)
{
    return cmd_copy_full(cmd, TRUE);
}