Mercurial > dovecot > core-2.2
view src/pop3/pop3-client.c @ 9235:2e2b957f1cca HEAD
Implemented anvil service, which is used to implement mail_max_userip_connections.
author | Timo Sirainen <tss@iki.fi> |
---|---|
date | Tue, 05 May 2009 21:28:34 -0400 |
parents | 97cdfeb57129 |
children | 0c587f108916 |
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/* Copyright (c) 2002-2009 Dovecot authors, see the included COPYING file */ #include "pop3-common.h" #include "buffer.h" #include "ioloop.h" #include "network.h" #include "istream.h" #include "ostream.h" #include "str.h" #include "hostpid.h" #include "var-expand.h" #include "master-service.h" #include "mail-storage.h" #include "pop3-commands.h" #include "mail-search-build.h" #include "mail-namespace.h" #include <stdlib.h> #include <unistd.h> /* max. length of input command line (spec says 512) */ #define MAX_INBUF_SIZE 2048 /* Stop reading input when output buffer has this many bytes. Once the buffer size has dropped to half of it, start reading input again. */ #define OUTBUF_THROTTLE_SIZE 4096 /* Disconnect client when it sends too many bad commands in a row */ #define CLIENT_MAX_BAD_COMMANDS 20 /* Disconnect client after idling this many milliseconds */ #define CLIENT_IDLE_TIMEOUT_MSECS (10*60*1000) /* If client starts idling for this many milliseconds, commit the current transaction. This allows the mailbox to become unlocked. */ #define CLIENT_COMMIT_TIMEOUT_MSECS (10*1000) struct client_workaround_list { const char *name; enum client_workarounds num; }; static struct client_workaround_list client_workaround_list[] = { { "outlook-no-nuls", WORKAROUND_OUTLOOK_NO_NULS }, { "oe-ns-eoh", WORKAROUND_OE_NS_EOH }, { NULL, 0 } }; static struct client *my_client; /* we don't need more than one currently */ static void client_input(struct client *client); static int client_output(struct client *client); static void client_commit_timeout(struct client *client) { if (client->cmd != NULL) { /* Can't commit while commands are running */ return; } (void)mailbox_transaction_commit(&client->trans); client->trans = mailbox_transaction_begin(client->mailbox, 0); } static void client_idle_timeout(struct client *client) { if (client->cmd != NULL) { client_destroy(client, "Disconnected for inactivity in reading our output"); } else { client_send_line(client, "-ERR Disconnected for inactivity."); client_destroy(client, "Disconnected for inactivity"); } } static bool init_mailbox(struct client *client, const char **error_r) { struct mail_search_args *search_args; struct mailbox_transaction_context *t; struct mail_search_context *ctx; struct mailbox_status status; struct mail *mail; buffer_t *message_sizes_buf; uint32_t failed_uid = 0; uoff_t size; int i; bool failed, expunged; message_sizes_buf = buffer_create_dynamic(default_pool, 512); search_args = mail_search_build_init(); mail_search_build_add_all(search_args); for (i = 0; i < 2; i++) { expunged = FALSE; if (mailbox_sync(client->mailbox, MAILBOX_SYNC_FLAG_FULL_READ, STATUS_UIDVALIDITY, &status) < 0) { client_send_storage_error(client); break; } client->uid_validity = status.uidvalidity; t = mailbox_transaction_begin(client->mailbox, 0); ctx = mailbox_search_init(t, search_args, NULL); client->last_seen = 0; client->total_size = 0; buffer_set_used_size(message_sizes_buf, 0); failed = FALSE; mail = mail_alloc(t, MAIL_FETCH_VIRTUAL_SIZE, NULL); while (mailbox_search_next(ctx, mail) > 0) { if (mail_get_virtual_size(mail, &size) < 0) { expunged = mail->expunged; failed = TRUE; if (failed_uid == mail->uid) { i_error("Getting size of message " "UID=%u failed", mail->uid); break; } failed_uid = mail->uid; break; } if ((mail_get_flags(mail) & MAIL_SEEN) != 0) client->last_seen = mail->seq; client->total_size += size; buffer_append(message_sizes_buf, &size, sizeof(size)); } client->messages_count = message_sizes_buf->used / sizeof(uoff_t); mail_free(&mail); if (mailbox_search_deinit(&ctx) < 0 || (failed && !expunged)) { client_send_storage_error(client); (void)mailbox_transaction_commit(&t); break; } if (!failed) { client->trans = t; client->message_sizes = buffer_free_without_data(&message_sizes_buf); mail_search_args_unref(&search_args); return TRUE; } /* well, sync and try again. we might have cached virtual sizes, make sure they get committed. */ (void)mailbox_transaction_commit(&t); } mail_search_args_unref(&search_args); if (expunged) { client_send_line(client, "-ERR [IN-USE] Couldn't sync mailbox."); *error_r = "Can't sync mailbox: Messages keep getting expunged"; } else { struct mail_storage *storage = client->inbox_ns->storage; enum mail_error error; *error_r = mail_storage_get_last_error(storage, &error); } buffer_free(&message_sizes_buf); return FALSE; } static enum client_workarounds parse_workarounds(const struct pop3_settings *set) { enum client_workarounds client_workarounds = 0; struct client_workaround_list *list; const char *const *str; str = t_strsplit_spaces(set->pop3_client_workarounds, " ,"); for (; *str != NULL; str++) { list = client_workaround_list; for (; list->name != NULL; list++) { if (strcasecmp(*str, list->name) == 0) { client_workarounds |= list->num; break; } } if (list->name == NULL) i_fatal("Unknown client workaround: %s", *str); } return client_workarounds; } static enum uidl_keys parse_uidl_keymask(const char *format) { enum uidl_keys mask = 0; for (; *format != '\0'; format++) { if (format[0] == '%' && format[1] != '\0') { switch (var_get_key(++format)) { case 'v': mask |= UIDL_UIDVALIDITY; break; case 'u': mask |= UIDL_UID; break; case 'm': mask |= UIDL_MD5; break; case 'f': mask |= UIDL_FILE_NAME; break; } } } return mask; } struct client *client_create(int fd_in, int fd_out, struct mail_user *user, const struct pop3_settings *set) { struct mail_storage *storage; const char *inbox, *ident; struct client *client; enum mailbox_open_flags flags; const char *errmsg; enum mail_error error; /* always use nonblocking I/O */ net_set_nonblock(fd_in, TRUE); net_set_nonblock(fd_out, TRUE); client = i_new(struct client, 1); client->set = set; client->fd_in = fd_in; client->fd_out = fd_out; client->input = i_stream_create_fd(fd_in, MAX_INBUF_SIZE, FALSE); client->output = o_stream_create_fd(fd_out, (size_t)-1, FALSE); o_stream_set_flush_callback(client->output, client_output, client); client->io = io_add(fd_in, IO_READ, client_input, client); client->last_input = ioloop_time; client->to_idle = timeout_add(CLIENT_IDLE_TIMEOUT_MSECS, client_idle_timeout, client); if (!set->pop3_lock_session) { client->to_commit = timeout_add(CLIENT_COMMIT_TIMEOUT_MSECS, client_commit_timeout, client); } client->user = user; inbox = "INBOX"; client->inbox_ns = mail_namespace_find(user->namespaces, &inbox); if (client->inbox_ns == NULL) { client_send_line(client, "-ERR No INBOX namespace for user."); client_destroy(client, "No INBOX namespace for user."); return NULL; } storage = client->inbox_ns->storage; client->mail_set = mail_storage_get_settings(storage); flags = MAILBOX_OPEN_POP3_SESSION; if (set->pop3_no_flag_updates) flags |= MAILBOX_OPEN_KEEP_RECENT; if (set->pop3_lock_session) flags |= MAILBOX_OPEN_KEEP_LOCKED; client->mailbox = mailbox_open(&storage, "INBOX", NULL, flags); if (client->mailbox == NULL) { errmsg = t_strdup_printf("Couldn't open INBOX: %s", mail_storage_get_last_error(storage, &error)); i_error("%s", errmsg); client_send_line(client, "-ERR [IN-USE] %s", errmsg); client_destroy(client, "Couldn't open INBOX"); return NULL; } if (!init_mailbox(client, &errmsg)) { i_error("Couldn't init INBOX: %s", errmsg); client_destroy(client, "Mailbox init failed"); return NULL; } client->workarounds = parse_workarounds(set); client->uidl_keymask = parse_uidl_keymask(client->mail_set->pop3_uidl_format); if (client->uidl_keymask == 0) i_fatal("Invalid pop3_uidl_format"); if (!set->pop3_no_flag_updates && client->messages_count > 0) client->seen_bitmask = i_malloc(MSGS_BITMASK_SIZE(client)); ident = mail_user_get_anvil_userip_ident(client->user); if (ident != NULL) { master_service_anvil_send(service, t_strconcat("CONNECT\t", my_pid, "\t", ident, "/pop3\n", NULL)); client->anvil_sent = TRUE; } i_assert(my_client == NULL); my_client = client; if (hook_client_created != NULL) hook_client_created(&client); return client; } static const char *client_stats(struct client *client) { static struct var_expand_table static_tab[] = { { 'p', NULL, "top_bytes" }, { 't', NULL, "top_count" }, { 'b', NULL, "retr_bytes" }, { 'r', NULL, "retr_count" }, { 'd', NULL, "deleted_count" }, { 'm', NULL, "message_count" }, { 's', NULL, "message_bytes" }, { 'i', NULL, "input" }, { 'o', NULL, "output" }, { '\0', NULL, NULL } }; struct var_expand_table *tab; string_t *str; tab = t_malloc(sizeof(static_tab)); memcpy(tab, static_tab, sizeof(static_tab)); tab[0].value = dec2str(client->top_bytes); tab[1].value = dec2str(client->top_count); tab[2].value = dec2str(client->retr_bytes); tab[3].value = dec2str(client->retr_count); tab[4].value = dec2str(client->expunged_count); tab[5].value = dec2str(client->messages_count); tab[6].value = dec2str(client->total_size); tab[7].value = dec2str(client->input->v_offset); tab[8].value = dec2str(client->output->offset); str = t_str_new(128); var_expand(str, client->set->pop3_logout_format, tab); return str_c(str); } static const char *client_get_disconnect_reason(struct client *client) { errno = client->input->stream_errno != 0 ? client->input->stream_errno : client->output->stream_errno; return errno == 0 || errno == EPIPE ? "Connection closed" : t_strdup_printf("Connection closed: %m"); } void client_destroy(struct client *client, const char *reason) { if (client->seen_change_count > 0) client_update_mails(client); if (!client->disconnected) { if (reason == NULL) reason = client_get_disconnect_reason(client); i_info("%s %s", reason, client_stats(client)); } if (client->cmd != NULL) { /* deinitialize command */ i_stream_close(client->input); o_stream_close(client->output); client->cmd(client); i_assert(client->cmd == NULL); } if (client->trans != NULL) { /* client didn't QUIT, but we still want to save any changes done in this transaction. especially the cached virtual message sizes. */ (void)mailbox_transaction_commit(&client->trans); } if (client->mailbox != NULL) mailbox_close(&client->mailbox); if (client->anvil_sent) { master_service_anvil_send(service, t_strconcat("DISCONNECT\t", my_pid, "\t", mail_user_get_anvil_userip_ident(client->user), "/pop3" "\n", NULL)); } mail_user_unref(&client->user); i_free(client->message_sizes); i_free(client->deleted_bitmask); i_free(client->seen_bitmask); if (client->io != NULL) io_remove(&client->io); timeout_remove(&client->to_idle); if (client->to_commit != NULL) timeout_remove(&client->to_commit); i_stream_destroy(&client->input); o_stream_destroy(&client->output); if (close(client->fd_in) < 0) i_error("close(client in) failed: %m"); if (client->fd_in != client->fd_out) { if (close(client->fd_out) < 0) i_error("close(client out) failed: %m"); } i_free(client); /* quit the program */ my_client = NULL; master_service_stop(service); } void client_disconnect(struct client *client, const char *reason) { if (client->disconnected) return; client->disconnected = TRUE; i_info("Disconnected: %s %s", reason, client_stats(client)); (void)o_stream_flush(client->output); i_stream_close(client->input); o_stream_close(client->output); } int client_send_line(struct client *client, const char *fmt, ...) { va_list va; ssize_t ret; if (client->output->closed) return -1; va_start(va, fmt); T_BEGIN { string_t *str; str = t_str_new(256); str_vprintfa(str, fmt, va); str_append(str, "\r\n"); ret = o_stream_send(client->output, str_data(str), str_len(str)); i_assert(ret < 0 || (size_t)ret == str_len(str)); } T_END; if (ret >= 0) { if (o_stream_get_buffer_used_size(client->output) < OUTBUF_THROTTLE_SIZE) { ret = 1; client->last_output = ioloop_time; } else { ret = 0; if (client->io != NULL) { /* no more input until client has read our output */ io_remove(&client->io); /* If someone happens to flush output, we want to get our IO handler back in flush callback */ o_stream_set_flush_pending(client->output, TRUE); } } } va_end(va); return (int)ret; } void client_send_storage_error(struct client *client) { enum mail_error error; if (mailbox_is_inconsistent(client->mailbox)) { client_send_line(client, "-ERR Mailbox is in inconsistent " "state, please relogin."); client_disconnect(client, "Mailbox is in inconsistent state."); return; } client_send_line(client, "-ERR %s", mail_storage_get_last_error(client->inbox_ns->storage, &error)); } bool client_handle_input(struct client *client) { char *line, *args; int ret; o_stream_cork(client->output); while (!client->output->closed && (line = i_stream_next_line(client->input)) != NULL) { args = strchr(line, ' '); if (args != NULL) *args++ = '\0'; T_BEGIN { ret = client_command_execute(client, line, args != NULL ? args : ""); } T_END; if (ret >= 0) { client->bad_counter = 0; if (client->cmd != NULL) { o_stream_set_flush_pending(client->output, TRUE); client->waiting_input = TRUE; break; } } else if (++client->bad_counter > CLIENT_MAX_BAD_COMMANDS) { client_send_line(client, "-ERR Too many bad commands."); client_disconnect(client, "Too many bad commands."); } } o_stream_uncork(client->output); if (client->output->closed) { client_destroy(client, NULL); return FALSE; } return TRUE; } static void client_input(struct client *client) { if (client->cmd != NULL) { /* we're still processing a command. wait until it's finished. */ io_remove(&client->io); client->waiting_input = TRUE; return; } client->waiting_input = FALSE; client->last_input = ioloop_time; timeout_reset(client->to_idle); if (client->to_commit != NULL) timeout_reset(client->to_commit); switch (i_stream_read(client->input)) { case -1: /* disconnected */ client_destroy(client, NULL); return; case -2: /* line too long, kill it */ client_send_line(client, "-ERR Input line too long."); client_destroy(client, "Input line too long"); return; } (void)client_handle_input(client); } static int client_output(struct client *client) { int ret; if ((ret = o_stream_flush(client->output)) < 0) { client_destroy(client, NULL); return 1; } client->last_output = ioloop_time; timeout_reset(client->to_idle); if (client->to_commit != NULL) timeout_reset(client->to_commit); if (client->cmd != NULL) { o_stream_cork(client->output); client->cmd(client); o_stream_uncork(client->output); } if (client->cmd == NULL) { if (o_stream_get_buffer_used_size(client->output) < OUTBUF_THROTTLE_SIZE/2 && client->io == NULL) { /* enable input again */ client->io = io_add(i_stream_get_fd(client->input), IO_READ, client_input, client); } if (client->io != NULL && client->waiting_input) client_input(client); } return client->cmd == NULL; } void clients_init(void) { my_client = NULL; } void clients_deinit(void) { if (my_client != NULL) { client_send_line(my_client, "-ERR Server shutting down."); client_destroy(my_client, "Server shutting down"); } }