Mercurial > dovecot > original-hg > dovecot-1.2
view src/imap/cmd-idle.c @ 9445:d7f8dbc38fd7 HEAD
imap: If client disconnects while appending, don't treat the rest of the message as commands.
author | Timo Sirainen <tss@iki.fi> |
---|---|
date | Tue, 20 Oct 2009 13:21:13 -0400 |
parents | 373b22cbabac |
children | 00cd9aacd03c |
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/* Copyright (c) 2002-2009 Dovecot authors, see the included COPYING file */ #include "common.h" #include "ioloop.h" #include "istream.h" #include "ostream.h" #include "crc32.h" #include "commands.h" #include "mail-user.h" #include "imap-sync.h" #include <stdlib.h> #define DEFAULT_IDLE_CHECK_INTERVAL 30 /* Send some noice to client every few minutes to avoid NATs and stateful firewalls from closing the connection */ #define DEFAULT_IMAP_IDLE_NOTIFY_INTERVAL (2*60) struct cmd_idle_context { struct client *client; struct client_command_context *cmd; struct imap_sync_context *sync_ctx; struct timeout *keepalive_to; unsigned int manual_cork:1; unsigned int sync_pending:1; }; static void idle_add_keepalive_timeout(struct cmd_idle_context *ctx); static bool cmd_idle_continue(struct client_command_context *cmd); static void idle_finish(struct cmd_idle_context *ctx, bool done_ok, bool free_cmd) { struct client *client = ctx->client; if (ctx->keepalive_to != NULL) timeout_remove(&ctx->keepalive_to); if (ctx->sync_ctx != NULL) { /* we're here only in connection failure cases */ (void)imap_sync_deinit(ctx->sync_ctx, ctx->cmd); } o_stream_cork(client->output); if (client->io != NULL) io_remove(&client->io); if (client->mailbox != NULL) mailbox_notify_changes_stop(client->mailbox); if (done_ok) client_send_tagline(ctx->cmd, "OK Idle completed."); else client_send_tagline(ctx->cmd, "BAD Expected DONE."); o_stream_uncork(client->output); if (free_cmd) client_command_free(&ctx->cmd); } static void idle_client_input(struct cmd_idle_context *ctx) { struct client *client = ctx->client; char *line; client->last_input = ioloop_time; timeout_reset(client->to_idle); switch (i_stream_read(client->input)) { case -1: /* disconnected */ client_destroy(client, "Disconnected in IDLE"); return; case -2: client->input_skip_line = TRUE; idle_finish(ctx, FALSE, TRUE); client_continue_pending_input(client); return; } if (ctx->sync_ctx != NULL) { /* we're still sending output to client. wait until it's all sent so we don't lose any changes. */ io_remove(&client->io); return; } while ((line = i_stream_next_line(client->input)) != NULL) { if (client->input_skip_line) client->input_skip_line = FALSE; else { idle_finish(ctx, strcasecmp(line, "DONE") == 0, TRUE); break; } } if (client->disconnected) client_destroy(client, NULL); else client_continue_pending_input(client); } static void keepalive_timeout(struct cmd_idle_context *ctx) { if (ctx->client->output_lock != NULL) { /* it's busy sending output */ return; } /* Sending this keeps NATs/stateful firewalls alive. Sending this also catches dead connections. */ client_send_line(ctx->client, "* OK Still here"); /* Make sure idling connections don't get disconnected. There are several clients that really want to IDLE forever and there's not much harm in letting them do so. */ timeout_reset(ctx->client->to_idle); /* recalculate time for the next keepalive timeout */ idle_add_keepalive_timeout(ctx); } static void idle_sync_now(struct mailbox *box, struct cmd_idle_context *ctx) { i_assert(ctx->sync_ctx == NULL); ctx->sync_pending = FALSE; ctx->sync_ctx = imap_sync_init(ctx->client, box, 0, 0); cmd_idle_continue(ctx->cmd); } static void idle_callback(struct mailbox *box, struct cmd_idle_context *ctx) { if (ctx->sync_ctx != NULL) ctx->sync_pending = TRUE; else { ctx->manual_cork = TRUE; idle_sync_now(box, ctx); } } static void idle_add_keepalive_timeout(struct cmd_idle_context *ctx) { const char *value; unsigned int interval; value = getenv("IMAP_IDLE_NOTIFY_INTERVAL"); interval = value != NULL ? (unsigned int)strtoul(value, NULL, 10) : DEFAULT_IMAP_IDLE_NOTIFY_INTERVAL; if (interval == 0) return; interval -= (time(NULL) + crc32_str(ctx->client->user->username)) % interval; if (ctx->keepalive_to != NULL) timeout_remove(&ctx->keepalive_to); ctx->keepalive_to = timeout_add(interval * 1000, keepalive_timeout, ctx); } static bool cmd_idle_continue(struct client_command_context *cmd) { struct client *client = cmd->client; struct cmd_idle_context *ctx = cmd->context; uoff_t orig_offset = client->output->offset; if (cmd->cancel) { idle_finish(ctx, FALSE, FALSE); return TRUE; } if (ctx->manual_cork) { /* we're coming from idle_callback instead of a normal I/O handler, so we'll have to do corking manually */ o_stream_cork(client->output); } if (ctx->sync_ctx != NULL) { if (imap_sync_more(ctx->sync_ctx) == 0) { /* unfinished */ if (ctx->manual_cork) { ctx->manual_cork = FALSE; o_stream_uncork(client->output); } cmd->state = CLIENT_COMMAND_STATE_WAIT_OUTPUT; return FALSE; } if (imap_sync_deinit(ctx->sync_ctx, ctx->cmd) < 0) { client_send_untagged_storage_error(client, mailbox_get_storage(client->mailbox)); mailbox_notify_changes_stop(client->mailbox); } ctx->sync_ctx = NULL; } if (client->output->offset != orig_offset && ctx->keepalive_to != NULL) idle_add_keepalive_timeout(ctx); if (ctx->sync_pending) { /* more changes occurred while we were sending changes to client */ idle_sync_now(client->mailbox, ctx); /* NOTE: this recurses back to this function, so we return here instead of doing everything twice. */ return FALSE; } cmd->state = CLIENT_COMMAND_STATE_WAIT_INPUT; if (ctx->manual_cork) { ctx->manual_cork = FALSE; o_stream_uncork(client->output); } if (client->output->closed) { idle_finish(ctx, FALSE, FALSE); return TRUE; } if (client->io == NULL) { /* input is pending */ client->io = io_add(i_stream_get_fd(client->input), IO_READ, idle_client_input, ctx); idle_client_input(ctx); } return FALSE; } bool cmd_idle(struct client_command_context *cmd) { struct client *client = cmd->client; struct cmd_idle_context *ctx; const char *str; unsigned int interval; ctx = p_new(cmd->pool, struct cmd_idle_context, 1); ctx->cmd = cmd; ctx->client = client; idle_add_keepalive_timeout(ctx); str = getenv("MAILBOX_IDLE_CHECK_INTERVAL"); interval = str == NULL ? 0 : (unsigned int)strtoul(str, NULL, 10); if (interval == 0) interval = DEFAULT_IDLE_CHECK_INTERVAL; if (client->mailbox != NULL) { mailbox_notify_changes(client->mailbox, interval, idle_callback, ctx); } client_send_line(client, "+ idling"); io_remove(&client->io); client->io = io_add(i_stream_get_fd(client->input), IO_READ, idle_client_input, ctx); cmd->func = cmd_idle_continue; cmd->context = ctx; /* check immediately if there are changes. if they came before we added mailbox-notifier, we wouldn't see them otherwise. */ if (client->mailbox != NULL) idle_sync_now(client->mailbox, ctx); return FALSE; }