src/lmtp/commands.c

	commands.c revision 30fc0b14f0d99a86c04aacff311e4cf2ddd5ff12
163N/A/* Copyright (c) 2009-2012 Dovecot authors, see the included COPYING file */
163N/A
163N/A#include "lib.h"
163N/A#include "ioloop.h"
163N/A#include "array.h"
163N/A#include "str.h"
163N/A#include "strescape.h"
163N/A#include "hostpid.h"
163N/A#include "istream.h"
163N/A#include "istream-concat.h"
163N/A#include "ostream.h"
163N/A#include "istream-dot.h"
163N/A#include "safe-mkstemp.h"
163N/A#include "restrict-access.h"
163N/A#include "master-service.h"
163N/A#include "rfc822-parser.h"
163N/A#include "message-date.h"
163N/A#include "auth-master.h"
163N/A#include "mail-storage-service.h"
163N/A#include "index/raw/raw-storage.h"
163N/A#include "lda-settings.h"
163N/A#include "lmtp-settings.h"
163N/A#include "mail-namespace.h"
163N/A#include "mail-deliver.h"
163N/A#include "main.h"
163N/A#include "client.h"
163N/A#include "commands.h"
163N/A#include "lmtp-proxy.h"
163N/A
211N/A#include <stdlib.h>
636N/A
636N/A#define ERRSTR_TEMP_MAILBOX_FAIL "451 4.3.0 <%s> Temporary internal error"
211N/A#define ERRSTR_TEMP_USERDB_FAIL_PREFIX "451 4.3.0 <%s> "
211N/A#define ERRSTR_TEMP_USERDB_FAIL \
636N/A    ERRSTR_TEMP_USERDB_FAIL_PREFIX "Temporary user lookup failure"
618N/A
163N/A#define LMTP_PROXY_DEFAULT_TIMEOUT_MSECS (1000*30)
163N/A
163N/Aint cmd_lhlo(struct client *client, const char *args)
163N/A{
163N/A    struct rfc822_parser_context parser;
211N/A    string_t *domain = t_str_new(128);
163N/A    const char *p;
163N/A    int ret = 0;
163N/A
163N/A    if (*args == '\0') {
163N/A        client_send_line(client, "501 Missing hostname");
163N/A        return 0;
163N/A    }
163N/A
163N/A    /* domain / address-literal */
163N/A    rfc822_parser_init(&parser, (const unsigned char *)args, strlen(args),
163N/A               NULL);
163N/A    if (*args != '[')
163N/A        ret = rfc822_parse_dot_atom(&parser, domain);
163N/A    else {
163N/A        for (p = args+1; *p != ']'; p++) {
163N/A            if (*p == '\\' || *p == '[')
163N/A                break;
163N/A        }
163N/A        if (strcmp(p, "]") != 0)
163N/A            ret = -1;
163N/A    }
163N/A    if (ret < 0) {
163N/A        str_truncate(domain, 0);
163N/A        str_append(domain, "invalid");
163N/A    }
163N/A
163N/A    client_state_reset(client);
163N/A    client_send_line(client, "250-%s", client->my_domain);
163N/A    client_send_line(client, "250-8BITMIME");
163N/A    client_send_line(client, "250-ENHANCEDSTATUSCODES");
211N/A    client_send_line(client, "250 PIPELINING");
163N/A
163N/A    i_free(client->lhlo);
163N/A    client->lhlo = i_strdup(str_c(domain));
163N/A    client_state_set(client, "LHLO");
163N/A    return 0;
211N/A}
163N/A
163N/Astatic int parse_address(const char *str, const char **address_r,
163N/A             const char **rest_r)
163N/A{
163N/A    const char *start;
163N/A
163N/A    if (*str++ != '<')
163N/A        return -1;
163N/A    start = str;
211N/A    if (*str == '"') {
211N/A        /* "quoted-string"@domain */
163N/A        for (str++; *str != '"'; str++) {
163N/A            if (*str == '\\')
163N/A                str++;
163N/A            if (*str == '\0')
163N/A                return -1;
163N/A        }
181N/A        str++;
163N/A    }
163N/A    for (; *str != '>'; str++) {
163N/A        if (*str == '\0' || *str == ' ')
163N/A            return -1;
    }
    *address_r = t_strdup_until(start, str);
    if (*str++ != '>')
        return -1;

    if (*str == ' ')
        str++;
    else if (*str != '\0')
        return -1;
    *rest_r = str;
    return 0;
}

int cmd_mail(struct client *client, const char *args)
{
    const char *addr, *const *argv;

    if (client->state.mail_from != NULL) {
        client_send_line(client, "503 5.5.1 MAIL already given");
        return 0;
    }

    if (strncasecmp(args, "FROM:", 5) != 0 ||
        parse_address(args + 5, &addr, &args) < 0) {
        client_send_line(client, "501 5.5.4 Invalid parameters");
        return 0;
    }

    argv = t_strsplit(args, " ");
    for (; *argv != NULL; argv++) {
        if (strcasecmp(*argv, "BODY=7BIT") == 0)
            client->state.mail_body_7bit = TRUE;
        else if (strcasecmp(*argv, "BODY=8BITMIME") == 0)
            client->state.mail_body_8bitmime = TRUE;
        else {
            client_send_line(client,
                "501 5.5.4 Unsupported options");
            return 0;
        }
    }

    client->state.mail_from = p_strdup(client->state_pool, addr);
    p_array_init(&client->state.rcpt_to, client->state_pool, 64);
    client_send_line(client, "250 2.1.0 OK");
    client_state_set(client, "MAIL FROM");
    return 0;
}

static bool
client_proxy_rcpt_parse_fields(struct lmtp_proxy_settings *set,
                   const char *const *args, const char **address)
{
    const char *p, *key, *value;
    bool proxying = FALSE, port_set = FALSE;

    for (; *args != NULL; args++) {
        p = strchr(*args, '=');
        if (p == NULL) {
            key = *args;
            value = "";
        } else {
            key = t_strdup_until(*args, p);
            value = p + 1;
        }

        if (strcmp(key, "proxy") == 0)
            proxying = TRUE;
        else if (strcmp(key, "host") == 0)
            set->host = value;
        else if (strcmp(key, "port") == 0) {
            set->port = atoi(value);
            port_set = TRUE;
        } else if (strcmp(key, "proxy_timeout") == 0)
            set->timeout_msecs = atoi(value)*1000;
        else if (strcmp(key, "protocol") == 0) {
            if (strcmp(value, "lmtp") == 0)
                set->protocol = LMTP_CLIENT_PROTOCOL_LMTP;
            else if (strcmp(value, "smtp") == 0) {
                set->protocol = LMTP_CLIENT_PROTOCOL_SMTP;
                if (!port_set)
                    set->port = 25;
            } else {
                i_error("proxy: Unknown protocol %s", value);
                return FALSE;
            }
        } else if (strcmp(key, "user") == 0 ||
               strcmp(key, "destuser") == 0) {
            /* changing the username */
            *address = value;
        } else {
            /* just ignore it */
        }
    }
    if (proxying && set->host == NULL) {
        i_error("proxy: host not given");
        return FALSE;
    }
    return proxying;
}

static bool
client_proxy_is_ourself(const struct client *client,
            const struct lmtp_proxy_settings *set)
{
    struct ip_addr ip;

    if (set->port != client->local_port)
        return FALSE;

    if (net_addr2ip(set->host, &ip) < 0)
        return FALSE;
    if (!net_ip_compare(&ip, &client->local_ip))
        return FALSE;
    return TRUE;
}

static const char *
address_add_detail(struct client *client, const char *username,
           const char *detail)
{
    const char *delim = client->set->recipient_delimiter;
    const char *domain;

    domain = strchr(username, '@');
    if (domain == NULL)
        return t_strconcat(username, delim, detail, NULL);
    else {
        username = t_strdup_until(username, domain);
        return t_strconcat(username, delim, detail, domain, NULL);
    }
}

static bool client_proxy_rcpt(struct client *client, const char *address,
                  const char *username, const char *detail)
{
    struct auth_master_connection *auth_conn;
    struct lmtp_proxy_settings set;
    struct auth_user_info info;
    struct mail_storage_service_input input;
    const char *args, *const *fields, *errstr, *orig_username = username;
    pool_t pool;
    int ret;

    memset(&input, 0, sizeof(input));
    input.module = input.service = "lmtp";
    mail_storage_service_init_settings(storage_service, &input);

    memset(&info, 0, sizeof(info));
    info.service = master_service_get_name(master_service);
    info.local_ip = client->local_ip;
    info.remote_ip = client->remote_ip;
    info.local_port = client->local_port;
    info.remote_port = client->remote_port;

    pool = pool_alloconly_create("auth lookup", 1024);
    auth_conn = mail_storage_service_get_auth_conn(storage_service);
    ret = auth_master_pass_lookup(auth_conn, username, &info,
                      pool, &fields);
    if (ret <= 0) {
        errstr = ret < 0 && fields[0] != NULL ? t_strdup(fields[0]) :
            t_strdup_printf(ERRSTR_TEMP_USERDB_FAIL, address);
        pool_unref(&pool);
        if (ret < 0) {
            client_send_line(client, "%s", errstr);
            return TRUE;
        } else {
            /* user not found from passdb. try userdb also. */
            return FALSE;
        }
    }

    memset(&set, 0, sizeof(set));
    set.port = client->local_port;
    set.protocol = LMTP_CLIENT_PROTOCOL_LMTP;
    set.timeout_msecs = LMTP_PROXY_DEFAULT_TIMEOUT_MSECS;

    if (!client_proxy_rcpt_parse_fields(&set, fields, &username)) {
        /* not proxying this user */
        pool_unref(&pool);
        return FALSE;
    }
    if (strcmp(username, orig_username) != 0) {
        /* username changed. change the address as well */
        if (*detail == '\0')
            address = username;
        else
            address = address_add_detail(client, username, detail);
    } else if (client_proxy_is_ourself(client, &set)) {
        i_error("Proxying to <%s> loops to itself", username);
        client_send_line(client, "554 5.4.6 <%s> "
                 "Proxying loops to itself", address);
        pool_unref(&pool);
        return TRUE;
    }

    if (array_count(&client->state.rcpt_to) != 0) {
        client_send_line(client, "451 4.3.0 <%s> "
            "Can't handle mixed proxy/non-proxy destinations",
            address);
        pool_unref(&pool);
        return TRUE;
    }
    if (client->proxy == NULL) {
        client->proxy = lmtp_proxy_init(client->set->hostname,
                        dns_client_socket_path,
                        client->state.session_id,
                        client->output);
        if (client->state.mail_body_8bitmime)
            args = " BODY=8BITMIME";
        else if (client->state.mail_body_7bit)
            args = " BODY=7BIT";
        else
            args = "";
        lmtp_proxy_mail_from(client->proxy, t_strdup_printf(
            "<%s>%s", client->state.mail_from, args));
    }
    if (lmtp_proxy_add_rcpt(client->proxy, address, &set) < 0)
        client_send_line(client, ERRSTR_TEMP_REMOTE_FAILURE);
    else
        client_send_line(client, "250 2.1.5 OK");
    pool_unref(&pool);
    return TRUE;
}

static const char *lmtp_unescape_address(const char *name)
{
    string_t *str;
    const char *p;

    if (*name != '"')
        return name;

    /* quoted-string local-part. drop the quotes unless there's a
       '@' character inside or there's an error. */
    str = t_str_new(128);
    for (p = name+1; *p != '"'; p++) {
        if (*p == '\0')
            return name;
        if (*p == '\\') {
            if (p[1] == '\0') {
                /* error */
                return name;
            }
            p++;
        }
        if (*p == '@')
            return name;
        str_append_c(str, *p);
    }
    p++;
    if (*p != '@' && *p != '\0')
        return name;

    str_append(str, p);
    return str_c(str);
}

static void rcpt_address_parse(struct client *client, const char *address,
                   const char **username_r, const char **detail_r)
{
    const char *p, *domain;

    *username_r = address;
    *detail_r = "";

    if (*client->set->recipient_delimiter == '\0')
        return;

    domain = strchr(address, '@');
    p = strstr(address, client->set->recipient_delimiter);
    if (p != NULL && (domain == NULL || p < domain)) {
        /* user+detail@domain */
        *username_r = t_strdup_until(*username_r, p);
        if (domain == NULL)
            *detail_r = p+1;
        else {
            *detail_r = t_strdup_until(p+1, domain);
            *username_r = t_strconcat(*username_r, domain, NULL);
        }
    }
}

static void lmtp_address_translate(struct client *client, const char **address)
{
    const char *transpos = client->lmtp_set->lmtp_address_translate;
    const char *p, *nextstr, *addrpos = *address;
    unsigned int len;
    string_t *username, *domain, *dest = NULL;

    if (*transpos == '\0')
        return;

    username = t_str_new(64);
    domain = t_str_new(64);

    /* check that string matches up to the first '%' */
    p = strchr(transpos, '%');
    if (p == NULL)
        len = strlen(transpos);
    else
        len = p-transpos;
    if (strncmp(transpos, addrpos, len) != 0)
        return;
    transpos += len;
    addrpos += len;

    while (*transpos != '\0') {
        switch (transpos[1]) {
        case 'n':
        case 'u':
            dest = username;
            break;
        case 'd':
            dest = domain;
            break;
        default:
            return;
        }
        transpos += 2;

        /* find where the next string starts */
        if (*transpos == '\0') {
            str_append(dest, addrpos);
            break;
        }
        p = strchr(transpos, '%');
        if (p == NULL)
            nextstr = transpos;
        else
            nextstr = t_strdup_until(transpos, p);
        p = strstr(addrpos, nextstr);
        if (p == NULL)
            return;
        str_append_n(dest, addrpos, p-addrpos);

        len = strlen(nextstr);
        transpos += len;
        addrpos = p + len;
    }
    str_append_c(username, '@');
    if (domain != NULL)
        str_append_str(username, domain);
    *address = str_c(username);
}

static int
lmtp_rcpt_to_is_over_quota(struct client *client,
               const struct mail_recipient *rcpt)
{
    struct mail_user *user;
    struct mail_namespace *ns;
    struct mailbox *box;
    struct mailbox_status status;
    const char *errstr;
    enum mail_error error;
    int ret;

    if (!client->lmtp_set->lmtp_rcpt_check_quota)
        return 0;

    ret = mail_storage_service_next(storage_service,
                    rcpt->service_user, &user);
    if (ret < 0)
        return -1;

    ns = mail_namespace_find_inbox(user->namespaces);
    box = mailbox_alloc(ns->list, "INBOX", 0);
    ret = mailbox_get_status(box, STATUS_CHECK_OVER_QUOTA, &status);
    if (ret < 0) {
        errstr = mailbox_get_last_error(box, &error);
        if (error == MAIL_ERROR_NOSPACE) {
            client_send_line(client, "552 5.2.2 <%s> %s",
                     rcpt->address, errstr);
            ret = 1;
        }
    }
    mailbox_free(&box);
    mail_user_unref(&user);
    return ret;
}

int cmd_rcpt(struct client *client, const char *args)
{
    struct mail_recipient rcpt;
    struct mail_storage_service_input input;
    const char *address, *username, *detail, *prefix;
    const char *error = NULL;
    int ret = 0;

    client_state_set(client, "RCPT TO");

    if (client->state.mail_from == NULL) {
        client_send_line(client, "503 5.5.1 MAIL needed first");
        return 0;
    }

    if (strncasecmp(args, "TO:", 3) != 0 ||
        parse_address(args + 3, &address, &args) < 0) {
        client_send_line(client, "501 5.5.4 Invalid parameters");
        return 0;
    }

    memset(&rcpt, 0, sizeof(rcpt));
    address = lmtp_unescape_address(address);

    if (*args != '\0') {
        client_send_line(client, "501 5.5.4 Unsupported options");
        return 0;
    }
    rcpt_address_parse(client, address, &username, &detail);

    if (client->lmtp_set->lmtp_proxy) {
        if (client_proxy_rcpt(client, address, username, detail))
            return 0;
    }

    memset(&input, 0, sizeof(input));
    input.module = input.service = "lmtp";
    input.username = username;
    input.local_ip = client->local_ip;
    input.remote_ip = client->remote_ip;
    input.local_port = client->local_port;
    input.remote_port = client->remote_port;

    ret = mail_storage_service_lookup(storage_service, &input,
                      &rcpt.service_user, &error);

    if (ret < 0) {
        prefix = t_strdup_printf(ERRSTR_TEMP_USERDB_FAIL_PREFIX,
                     username);
        client_send_line(client, "%s%s", prefix, error);
        return 0;
    }
    if (ret == 0) {
        client_send_line(client,
                 "550 5.1.1 <%s> User doesn't exist: %s",
                 address, username);
        return 0;
    }
    if (client->proxy != NULL) {
        /* NOTE: if this restriction is ever removed, we'll also need
           to send different message bodies to local and proxy
           (with and without Return-Path: header) */
        client_send_line(client, "451 4.3.0 <%s> "
            "Can't handle mixed proxy/non-proxy destinations",
            address);
        return 0;
    }

    lmtp_address_translate(client, &address);

    rcpt.address = p_strdup(client->state_pool, address);
    rcpt.detail = p_strdup(client->state_pool, detail);
    if ((ret = lmtp_rcpt_to_is_over_quota(client, &rcpt)) < 0) {
        client_send_line(client, ERRSTR_TEMP_MAILBOX_FAIL,
                 rcpt.address);
        return 0;
    }
    if (ret == 0) {
        array_append(&client->state.rcpt_to, &rcpt, 1);
        client_send_line(client, "250 2.1.5 OK");
    }
    return 0;
}

int cmd_quit(struct client *client, const char *args ATTR_UNUSED)
{
    client_destroy(client, "221 2.0.0", "Client quit");
    return -1;
}

int cmd_vrfy(struct client *client, const char *args ATTR_UNUSED)
{
    client_send_line(client, "252 2.3.3 Try RCPT instead");
    return 0;
}

int cmd_rset(struct client *client, const char *args ATTR_UNUSED)
{
    client_state_reset(client);
    client_send_line(client, "250 2.0.0 OK");
    return 0;
}

int cmd_noop(struct client *client, const char *args ATTR_UNUSED)
{
    client_send_line(client, "250 2.0.0 OK");
    return 0;
}

static int
client_deliver(struct client *client, const struct mail_recipient *rcpt,
           struct mail *src_mail, struct mail_deliver_session *session)
{
    struct mail_deliver_context dctx;
    struct mail_storage *storage;
    const struct mail_storage_service_input *input;
    struct mail_namespace *ns;
    void **sets;
    const char *error, *username;
    enum mail_error mail_error;
    int ret;

    input = mail_storage_service_user_get_input(rcpt->service_user);
    username = t_strdup(input->username);

    i_set_failure_prefix(t_strdup_printf("lmtp(%s, %s): ",
                         my_pid, username));
    if (mail_storage_service_next(storage_service, rcpt->service_user,
                      &client->state.dest_user) < 0) {
        client_send_line(client, ERRSTR_TEMP_MAILBOX_FAIL,
                 rcpt->address);
        return -1;
    }
    sets = mail_storage_service_user_get_set(rcpt->service_user);

    memset(&dctx, 0, sizeof(dctx));
    dctx.session = session;
    dctx.pool = session->pool;
    dctx.set = sets[1];
    dctx.session_id = client->state.session_id;
    dctx.src_mail = src_mail;
    dctx.src_envelope_sender = client->state.mail_from;
    dctx.dest_user = client->state.dest_user;
    if (*dctx.set->lda_original_recipient_header != '\0') {
        dctx.dest_addr = mail_deliver_get_address(src_mail,
                dctx.set->lda_original_recipient_header);
    }
    if (dctx.dest_addr == NULL)
        dctx.dest_addr = rcpt->address;
    dctx.final_dest_addr = rcpt->address;
    if (*rcpt->detail == '\0' ||
        !client->lmtp_set->lmtp_save_to_detail_mailbox)
        dctx.dest_mailbox_name = "INBOX";
    else {
        ns = mail_namespace_find_inbox(dctx.dest_user->namespaces);
        dctx.dest_mailbox_name =
            t_strconcat(ns->prefix, rcpt->detail, NULL);
    }

    dctx.save_dest_mail = array_count(&client->state.rcpt_to) > 1 &&
        client->state.first_saved_mail == NULL;

    if (mail_deliver(&dctx, &storage) == 0) {
        if (dctx.dest_mail != NULL) {
            i_assert(client->state.first_saved_mail == NULL);
            client->state.first_saved_mail = dctx.dest_mail;
        }
        client_send_line(client, "250 2.0.0 <%s> %s Saved",
                 rcpt->address, client->state.session_id);
        ret = 0;
    } else if (storage == NULL) {
        /* This shouldn't happen */
        i_error("BUG: Saving failed to unknown storage");
        client_send_line(client, ERRSTR_TEMP_MAILBOX_FAIL,
                 rcpt->address);
        ret = -1;
    } else {
        error = mail_storage_get_last_error(storage, &mail_error);
        if (mail_error == MAIL_ERROR_NOSPACE) {
            client_send_line(client, "%s <%s> %s",
                     dctx.set->quota_full_tempfail ?
                     "452 4.2.2" : "552 5.2.2",
                     rcpt->address, error);
        } else {
            client_send_line(client, "451 4.2.0 <%s> %s",
                     rcpt->address, error);
        }
        ret = -1;
    }
    return ret;
}

static bool client_deliver_next(struct client *client, struct mail *src_mail,
                struct mail_deliver_session *session)
{
    const struct mail_recipient *rcpts;
    unsigned int count;
    int ret;

    rcpts = array_get(&client->state.rcpt_to, &count);
    while (client->state.rcpt_idx < count) {
        ret = client_deliver(client, &rcpts[client->state.rcpt_idx],
                     src_mail, session);
        i_set_failure_prefix(t_strdup_printf("lmtp(%s): ", my_pid));

        client->state.rcpt_idx++;
        if (ret == 0)
            return TRUE;
        /* failed. try the next one. */
        if (client->state.dest_user != NULL)
            mail_user_unref(&client->state.dest_user);
    }
    return FALSE;
}

static void client_rcpt_fail_all(struct client *client)
{
    const struct mail_recipient *rcpt;

    array_foreach(&client->state.rcpt_to, rcpt) {
        client_send_line(client, ERRSTR_TEMP_MAILBOX_FAIL,
                 rcpt->address);
    }
}

static struct istream *client_get_input(struct client *client)
{
    struct client_state *state = &client->state;
    struct istream *cinput, *inputs[3];

    inputs[0] = i_stream_create_from_data(state->added_headers,
                          strlen(state->added_headers));

    if (state->mail_data_output != NULL) {
        o_stream_unref(&state->mail_data_output);
        inputs[1] = i_stream_create_fd(state->mail_data_fd,
                           MAIL_READ_FULL_BLOCK_SIZE,
                           FALSE);
        i_stream_set_init_buffer_size(inputs[1],
                          MAIL_READ_FULL_BLOCK_SIZE);
    } else {
        inputs[1] = i_stream_create_from_data(state->mail_data->data,
                              state->mail_data->used);
    }
    inputs[2] = NULL;

    cinput = i_stream_create_concat(inputs);
    i_stream_unref(&inputs[0]);
    i_stream_unref(&inputs[1]);
    return cinput;
}

static int client_open_raw_mail(struct client *client, struct istream *input)
{
    static const char *wanted_headers[] = {
        "From", "To", "Message-ID", "Subject", "Return-Path",
        NULL
    };
    struct mailbox *box;
    struct mailbox_transaction_context *trans;
    struct mailbox_header_lookup_ctx *headers_ctx;
    enum mail_error error;

    if (raw_mailbox_alloc_stream(client->raw_mail_user, input,
                     (time_t)-1, client->state.mail_from,
                     &box) < 0) {
        i_error("Can't open delivery mail as raw: %s",
            mailbox_get_last_error(box, &error));
        mailbox_free(&box);
        client_rcpt_fail_all(client);
        return -1;
    }

    trans = mailbox_transaction_begin(box, 0);

    headers_ctx = mailbox_header_lookup_init(box, wanted_headers);
    client->state.raw_mail = mail_alloc(trans, 0, headers_ctx);
    mailbox_header_lookup_unref(&headers_ctx);
    mail_set_seq(client->state.raw_mail, 1);
    return 0;
}

static void
client_input_data_write_local(struct client *client, struct istream *input)
{
    struct mail_deliver_session *session;
    struct mail *src_mail;
    uid_t old_uid, first_uid = (uid_t)-1;

    if (client_open_raw_mail(client, input) < 0)
        return;

    session = mail_deliver_session_init();
    old_uid = geteuid();
    src_mail = client->state.raw_mail;
    while (client_deliver_next(client, src_mail, session)) {
        if (client->state.first_saved_mail == NULL ||
            client->state.first_saved_mail == src_mail)
            mail_user_unref(&client->state.dest_user);
        else {
            /* use the first saved message to save it elsewhere too.
               this might allow hard linking the files. */
            client->state.dest_user = NULL;
            src_mail = client->state.first_saved_mail;
            first_uid = geteuid();
            i_assert(first_uid != 0);
        }
    }
    mail_deliver_session_deinit(&session);

    if (client->state.first_saved_mail != NULL) {
        struct mail *mail = client->state.first_saved_mail;
        struct mailbox_transaction_context *trans = mail->transaction;
        struct mailbox *box = trans->box;
        struct mail_user *user = box->storage->user;

        /* just in case these functions are going to write anything,
           change uid back to user's own one */
        if (first_uid != old_uid) {
            if (seteuid(0) < 0)
                i_fatal("seteuid(0) failed: %m");
            if (seteuid(first_uid) < 0)
                i_fatal("seteuid() failed: %m");
        }

        mail_free(&mail);
        mailbox_transaction_rollback(&trans);
        mailbox_free(&box);
        mail_user_unref(&user);
    }

    if (old_uid == 0) {
        /* switch back to running as root, since that's what we're
           practically doing anyway. it's also important in case we
           lose e.g. config connection and need to reconnect to it. */
        if (seteuid(0) < 0)
            i_fatal("seteuid(0) failed: %m");
        /* enable core dumping again. we need to chdir also to
           root-owned directory to get core dumps. */
        restrict_access_allow_coredumps(TRUE);
        (void)chdir(base_dir);
    }
}

static void client_input_data_finish(struct client *client)
{
    client_io_reset(client);
    client_state_reset(client);
    if (i_stream_have_bytes_left(client->input))
        client_input_handle(client);
}

static void client_proxy_finish(void *context)
{
    struct client *client = context;

    lmtp_proxy_deinit(&client->proxy);
    client_input_data_finish(client);
}

static const char *client_get_added_headers(struct client *client)
{
    string_t *str = t_str_new(200);
    const char *host, *rcpt_to = NULL;

    if (array_count(&client->state.rcpt_to) == 1) {
        const struct mail_recipient *rcpt =
            array_idx(&client->state.rcpt_to, 0);

        rcpt_to = rcpt->address;
    }

    /* don't set Return-Path when proxying so it won't get added twice */
    if (array_count(&client->state.rcpt_to) > 0) {
        str_printfa(str, "Return-Path: <%s>\r\n",
                client->state.mail_from);
        if (rcpt_to != NULL)
            str_printfa(str, "Delivered-To: <%s>\r\n", rcpt_to);
    }

    str_printfa(str, "Received: from %s", client->lhlo);
    if ((host = net_ip2addr(&client->remote_ip)) != NULL)
        str_printfa(str, " ([%s])", host);
    str_printfa(str, "\r\n\tby %s ("PACKAGE_NAME") with LMTP id %s",
            client->my_domain, client->state.session_id);

    str_append(str, "\r\n\t");
    if (rcpt_to != NULL)
        str_printfa(str, "for <%s>", rcpt_to);
    str_printfa(str, "; %s\r\n", message_date_create(ioloop_time));
    return str_c(str);
}

static bool client_input_data_write(struct client *client)
{
    struct istream *input;
    bool ret = TRUE;

    /* stop handling client input until saving/proxying is finished */
    if (client->to_idle != NULL)
        timeout_remove(&client->to_idle);
    io_remove(&client->io);
    i_stream_destroy(&client->dot_input);

    input = client_get_input(client);
    if (array_count(&client->state.rcpt_to) != 0)
        client_input_data_write_local(client, input);
    if (client->proxy != NULL) {
        lmtp_proxy_start(client->proxy, input, NULL,
                 client_proxy_finish, client);
        ret = FALSE;
    }
    i_stream_unref(&input);
    return ret;
}

static int client_input_add_file(struct client *client,
                 const unsigned char *data, size_t size)
{
    struct client_state *state = &client->state;
    string_t *path;
    ssize_t ret;
    int fd;

    if (state->mail_data_output != NULL) {
        /* continue writing to file */
        if (o_stream_send(state->mail_data_output,
                  data, size) != (ssize_t)size)
            return -1;
        return 0;
    }

    /* move everything to a temporary file. */
    path = t_str_new(256);
    mail_user_set_get_temp_prefix(path, client->raw_mail_user->set);
    fd = safe_mkstemp_hostpid(path, 0600, (uid_t)-1, (gid_t)-1);
    if (fd == -1) {
        i_error("Temp file creation to %s failed: %m", str_c(path));
        return -1;
    }

    /* we just want the fd, unlink it */
    if (unlink(str_c(path)) < 0) {
        /* shouldn't happen.. */
        i_error("unlink(%s) failed: %m", str_c(path));
        (void)close(fd);
        return -1;
    }

    state->mail_data_fd = fd;
    state->mail_data_output = o_stream_create_fd_file(fd, 0, FALSE);
    o_stream_cork(state->mail_data_output);

    ret = o_stream_send(state->mail_data_output,
                state->mail_data->data, state->mail_data->used);
    if (ret != (ssize_t)state->mail_data->used)
        return -1;
    if (o_stream_send(client->state.mail_data_output,
              data, size) != (ssize_t)size)
        return -1;
    return 0;
}

static int
client_input_add(struct client *client, const unsigned char *data, size_t size)
{
    if (client->state.mail_data->used + size <=
        CLIENT_MAIL_DATA_MAX_INMEMORY_SIZE &&
        client->state.mail_data_output == NULL) {
        buffer_append(client->state.mail_data, data, size);
        return 0;
    } else {
        return client_input_add_file(client, data, size);
    }
}

static void client_input_data_handle(struct client *client)
{
    const unsigned char *data;
    size_t size;
    ssize_t ret;

    while ((ret = i_stream_read(client->dot_input)) > 0 || ret == -2) {
        data = i_stream_get_data(client->dot_input, &size);
        if (client_input_add(client, data, size) < 0) {
            client_destroy(client, "451 4.3.0",
                       "Temporary internal failure");
            return;
        }
        i_stream_skip(client->dot_input, size);
    }
    if (ret == 0)
        return;

    if (!client->dot_input->eof) {
        /* client probably disconnected */
        client_destroy(client, NULL, NULL);
        return;
    }

    if (client_input_data_write(client))
        client_input_data_finish(client);
}

static void client_input_data(struct client *client)
{
    if (client_input_read(client) < 0)
        return;

    client_input_data_handle(client);
}

int cmd_data(struct client *client, const char *args ATTR_UNUSED)
{
    if (client->state.mail_from == NULL) {
        client_send_line(client, "503 5.5.1 MAIL needed first");
        return 0;
    }
    if (array_count(&client->state.rcpt_to) == 0 && client->proxy == NULL) {
        client_send_line(client, "554 5.5.1 No valid recipients");
        return 0;
    }

    client->state.added_headers =
        p_strdup(client->state_pool, client_get_added_headers(client));

    i_assert(client->state.mail_data == NULL);
    client->state.mail_data = buffer_create_dynamic(default_pool, 1024*64);

    i_assert(client->dot_input == NULL);
    client->dot_input = i_stream_create_dot(client->input, TRUE);
    client_send_line(client, "354 OK");

    io_remove(&client->io);
    client_state_set(client, "DATA");
    client->io = io_add(client->fd_in, IO_READ, client_input_data, client);
    client_input_data_handle(client);
    return -1;
}