src/lib-smtp/smtp-server-private.h

#ifndef SMTP_SERVER_PRIVATE_H
#define SMTP_SERVER_PRIVATE_H

#include "connection.h"

#include "smtp-server.h"

#define SMTP_SERVER_COMMAND_POOL_MAX          (8 * 1024)

#define SMTP_SERVER_DEFAULT_MAX_COMMAND_LINE  (4 * 1024)
#define SMTP_SERVER_DEFAULT_MAX_BAD_COMMANDS  10

#define SMTP_SERVER_DEFAULT_CAPABILITIES \
    (SMTP_CAPABILITY_SIZE | SMTP_CAPABILITY_ENHANCEDSTATUSCODES | \
        SMTP_CAPABILITY_8BITMIME | SMTP_CAPABILITY_CHUNKING)

struct smtp_server_reply;
struct smtp_server_command;
struct smtp_server_connection;

ARRAY_DEFINE_TYPE(smtp_server_reply, struct smtp_server_reply);

enum smtp_server_command_state {
    /* New command; callback to command start handler executing. */
    SMTP_SERVER_COMMAND_STATE_NEW = 0,
    /* This command is being processed; command data is fully read, but no
       reply is yet submitted */
    SMTP_SERVER_COMMAND_STATE_PROCESSING,
    /* A reply is submitted for this command. If not all command data was
       read by the handler, it is first skipped on the input. If this is a
       multi-reply command (LMTP->DATA), not all replies may be submitted
       yet. */
    SMTP_SERVER_COMMAND_STATE_SUBMITTED_REPLY,
    /* Request is ready for sending reply; a reply is submitted and the
       command payload is fully read. If this is a multi-reply command
       (LMTP->DATA), not all replies may be submitted yet. In that case the
       command state goes back to PROCESSING once the all submitted replies
       are sent. */
    SMTP_SERVER_COMMAND_STATE_READY_TO_REPLY,
    /* The reply for the command is sent */
    SMTP_SERVER_COMMAND_STATE_FINISHED,
    /* Request is aborted; still lingering due to references */
    SMTP_SERVER_COMMAND_STATE_ABORTED
};

struct smtp_server_reply_content {
    unsigned int status;
    const char *status_prefix;

    string_t *text;
    size_t last_line;
};

struct smtp_server_reply {
    struct smtp_server_command *command;
    unsigned int index;

    /* replies may share content */
    struct smtp_server_reply_content *content;

    bool submitted:1;
    bool sent:1;
};

struct smtp_server_command_reg {
    const char *name;
    enum smtp_server_command_flags flags;
    smtp_server_cmd_start_func_t *func;
};

struct smtp_server_command {
    struct smtp_server_cmd_ctx context;
    const struct smtp_server_command_reg *reg;

    unsigned int refcount;

    enum smtp_server_command_state state;

    struct smtp_server_command *prev, *next;

    ARRAY_TYPE(smtp_server_reply) replies;
    unsigned int replies_expected;
    unsigned int replies_submitted;

    /* private hooks */

    /* next: command is next to reply but has not submittted all replies yet */
    smtp_server_cmd_func_t *hook_next;
    /* replied: command has submitted all replies */
    smtp_server_cmd_func_t *hook_replied;
    /* completed: server is about to send last replies for this command */
    smtp_server_cmd_func_t *hook_completed;
    /* destroy: command is about to be destroyed */
    smtp_server_cmd_func_t *hook_destroy;
    /* private context data */
    void *data;

    bool input_locked:1;
    bool input_captured:1;
    bool reply_early:1;
};

struct smtp_server_state_data {
    enum smtp_server_state state;
    time_t timestamp;

    unsigned int pending_mail_cmds, pending_rcpt_cmds;

    struct smtp_server_transaction *trans;
    struct istream *data_input, *data_chain_input;
    struct istream_chain *data_chain;
    unsigned int data_chunks;

    bool data_failed:1;
};

struct smtp_server_connection {
    struct connection conn;
    struct smtp_server *server;
    pool_t pool;
    unsigned int refcount;

    struct smtp_server_settings set;
    const struct smtp_server_callbacks *callbacks;
    void *context;

    unsigned int socket_family;
    struct ip_addr remote_ip;
    in_port_t remote_port;
    pid_t remote_pid;
    uid_t remote_uid;

    enum smtp_proxy_protocol proxy_proto;
    unsigned int proxy_ttl_plus_1;
    unsigned int proxy_timeout_secs;

    struct smtp_server_helo_data helo, *pending_helo;
    char *helo_domain, *helo_login, *username;
    unsigned int id;

    struct timeout *to_idle;
    struct istream *raw_input;
    struct ostream *raw_output;
    struct ssl_iostream *ssl_iostream;
    struct smtp_command_parser *smtp_parser;

    struct smtp_server_command *command_queue_head, *command_queue_tail;
    unsigned int command_queue_count;
    unsigned int bad_counter;

    char *disconnect_reason;

    struct smtp_server_state_data state;

    struct smtp_server_stats stats;

    bool started:1;
    bool halted:1;
    bool ssl_start:1;
    bool ssl_secured:1;
    bool authenticated:1;
    bool created_from_streams:1;
    bool corked:1;
    bool disconnected:1;
    bool closing:1;
    bool closed:1;
    bool input_broken:1;
    bool input_locked:1;
    bool handling_input:1;
    bool rawlog_checked:1;
    bool rawlog_enabled:1;
};

struct smtp_server {
    pool_t pool;

    struct smtp_server_settings set;

    struct ioloop *ioloop;

    ARRAY(struct smtp_server_command_reg) commands_reg;

    struct connection_list *conn_list;

    bool commands_unsorted:1;
};

static inline const char *
smtp_server_command_label(struct smtp_server_command *cmd)
{
    if (cmd->context.name == NULL)
        return "[INVALID]";
    return cmd->context.name;
}

static inline const char *
smtp_server_connection_label(struct smtp_server_connection *conn)
{
    return conn->conn.name;
}

bool smtp_server_connection_pending_command_data(
    struct smtp_server_connection *conn);

/*
 * Reply
 */

void smtp_server_reply_free(struct smtp_server_command *cmd);

int smtp_server_reply_send(struct smtp_server_reply *resp);

const char *smtp_server_reply_get_one_line(struct smtp_server_reply *reply);

/*
 * Command
 */

void smtp_server_commands_init(struct smtp_server *server);

void smtp_server_command_debug(struct smtp_server_cmd_ctx *cmd,
    const char *format, ...) ATTR_FORMAT(2, 3);

struct smtp_server_command *
smtp_server_command_alloc(struct smtp_server_connection *conn);
struct smtp_server_command *
smtp_server_command_new(struct smtp_server_connection *conn,
    const char *name, const char *params);
void smtp_server_command_ref(struct smtp_server_command *cmd);
bool smtp_server_command_unref(struct smtp_server_command **_cmd);
void smtp_server_command_abort(struct smtp_server_command **_cmd);

void smtp_server_command_submit_reply(struct smtp_server_command *cmd);

int smtp_server_connection_flush(struct smtp_server_connection *conn);

void smtp_server_command_ready_to_reply(struct smtp_server_command *cmd);
void smtp_server_command_next_to_reply(struct smtp_server_command *cmd);
void smtp_server_command_completed(struct smtp_server_command *cmd);
void smtp_server_command_finished(struct smtp_server_command *cmd);

static inline bool
smtp_server_command_is_complete(struct smtp_server_command *cmd)
{
    struct smtp_server_connection *conn = cmd->context.conn;

    return (conn->input_broken || (cmd->next != NULL) || cmd->reply_early ||
        !smtp_server_connection_pending_command_data(conn));
}

void smtp_server_cmd_ehlo(struct smtp_server_cmd_ctx *cmd,
    const char *params);
void smtp_server_cmd_helo(struct smtp_server_cmd_ctx *cmd,
    const char *params);
void smtp_server_cmd_xclient(struct smtp_server_cmd_ctx *cmd,
    const char *params);

void smtp_server_cmd_starttls(struct smtp_server_cmd_ctx *cmd,
    const char *params);
void smtp_server_cmd_auth(struct smtp_server_cmd_ctx *cmd,
    const char *params);

void smtp_server_cmd_mail(struct smtp_server_cmd_ctx *cmd,
    const char *params);
void smtp_server_cmd_rcpt(struct smtp_server_cmd_ctx *cmd,
    const char *params);
void smtp_server_cmd_data(struct smtp_server_cmd_ctx *cmd,
    const char *params);
void smtp_server_cmd_bdat(struct smtp_server_cmd_ctx *cmd,
    const char *params);
void smtp_server_cmd_rset(struct smtp_server_cmd_ctx *cmd,
    const char *params);

void smtp_server_cmd_noop(struct smtp_server_cmd_ctx *cmd,
    const char *params);
void smtp_server_cmd_vrfy(struct smtp_server_cmd_ctx *cmd,
    const char *params);

void smtp_server_cmd_quit(struct smtp_server_cmd_ctx *cmd,
    const char *params);

/*
 * Connection
 */

typedef void smtp_server_input_callback_t(void *context);

void smtp_server_connection_debug(struct smtp_server_connection *conn,
    const char *format, ...) ATTR_FORMAT(2, 3);
void smtp_server_connection_error(struct smtp_server_connection *conn,
    const char *format, ...) ATTR_FORMAT(2, 3);

struct connection_list *smtp_server_connection_list_init(void);

void smtp_server_connection_switch_ioloop(struct smtp_server_connection *conn);

void smtp_server_connection_handle_output_error(
    struct smtp_server_connection *conn);
void smtp_server_connection_trigger_output(struct smtp_server_connection *conn);
bool smtp_server_connection_pending_payload(struct smtp_server_connection *conn);

void smtp_server_connection_cork(struct smtp_server_connection *conn);
void smtp_server_connection_uncork(struct smtp_server_connection *conn);

void smtp_server_connection_input_halt(struct smtp_server_connection *conn);
void smtp_server_connection_input_resume(struct smtp_server_connection *conn);
void smtp_server_connection_input_capture(
    struct smtp_server_connection *conn,
    smtp_server_input_callback_t *callback, void *context);
#define smtp_server_connection_input_capture(conn, callback, context) \
    smtp_server_connection_input_capture(conn + \
        CALLBACK_TYPECHECK(callback, void (*)(typeof(context))), \
        (smtp_server_input_callback_t *)callback, context)

void smtp_server_connection_timeout_stop(struct smtp_server_connection *conn);
void smtp_server_connection_timeout_start(struct smtp_server_connection *conn);
void smtp_server_connection_timeout_reset(struct smtp_server_connection *conn);

void smtp_server_connection_send_line(struct smtp_server_connection *conn,
    const char *fmt, ...) ATTR_FORMAT(2, 3);
void smtp_server_connection_reply_immediate(
    struct smtp_server_connection *conn, unsigned int status,
    const char *fmt, ...) ATTR_FORMAT(3, 4);

void smtp_server_connection_reset_state(struct smtp_server_connection *conn);
void smtp_server_connection_set_state(struct smtp_server_connection *conn,
    enum smtp_server_state state);

int smtp_server_connection_ssl_init(struct smtp_server_connection *conn);

void smtp_server_connection_clear(struct smtp_server_connection *conn);

struct smtp_server_transaction *
smtp_server_connection_get_transaction(struct smtp_server_connection *conn);

void smtp_server_connection_set_proxy_data(struct smtp_server_connection *conn,
    const struct smtp_proxy_data *proxy_data);

/*
 * Transaction
 */

struct smtp_server_transaction *
smtp_server_transaction_create(struct smtp_server_connection *conn,
    const struct smtp_address *mail_from,
    const struct smtp_params_mail *params,
    const struct timeval *timestamp);
void smtp_server_transaction_free(struct smtp_server_transaction **_trans);

struct smtp_server_recipient *
smtp_server_transaction_add_rcpt(struct smtp_server_transaction *trans,
    const struct smtp_address *rcpt_to,
    const struct smtp_params_rcpt *params);
bool smtp_server_transaction_has_rcpt(struct smtp_server_transaction *trans);
unsigned int
smtp_server_transaction_rcpt_count(struct smtp_server_transaction *trans);

#endif