ngx_mail_handler.c

Nginx是一个高性能的HTTP和反向代理服务器

    ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
                   "mail auth login username: \"%V\"", &s->login);

    return NGX_OK;
}


ngx_int_t
ngx_mail_auth_login_password(ngx_mail_session_t *s, ngx_connection_t *c)
{
    ngx_str_t  *arg;

    arg = s->args.elts;

#if (NGX_DEBUG_MAIL_PASSWD)
    ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
                   "mail auth login password: \"%V\"", &arg[0]);
#endif

    s->passwd.data = ngx_palloc(c->pool, ngx_base64_decoded_length(arg[0].len));
    if (s->passwd.data == NULL){
        return NGX_ERROR;
    }

    if (ngx_decode_base64(&s->passwd, &arg[0]) != NGX_OK) {
        ngx_log_error(NGX_LOG_INFO, c->log, 0,
            "client sent invalid base64 encoding in AUTH LOGIN command");
        return NGX_MAIL_PARSE_INVALID_COMMAND;
    }

#if (NGX_DEBUG_MAIL_PASSWD)
    ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
                   "mail auth login password: \"%V\"", &s->passwd);
#endif

    return NGX_DONE;
}


ngx_int_t
ngx_mail_auth_cram_md5_salt(ngx_mail_session_t *s, ngx_connection_t *c,
    char *prefix, size_t len)
{
    u_char      *p;
    ngx_str_t    salt;
    ngx_uint_t   n;

    p = ngx_palloc(c->pool, len + ngx_base64_encoded_length(s->salt.len) + 2);
    if (p == NULL) {
        return NGX_ERROR;
    }

    salt.data = ngx_cpymem(p, prefix, len);
    s->salt.len -= 2;

    ngx_encode_base64(&salt, &s->salt);

    s->salt.len += 2;
    n = len + salt.len;
    p[n++] = CR; p[n++] = LF;

    s->out.len = n;
    s->out.data = p;

    return NGX_OK;
}


ngx_int_t
ngx_mail_auth_cram_md5(ngx_mail_session_t *s, ngx_connection_t *c)
{
    u_char     *p, *last;
    ngx_str_t  *arg;

    arg = s->args.elts;

    ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
                   "mail auth cram-md5: \"%V\"", &arg[0]);

    s->login.data = ngx_palloc(c->pool, ngx_base64_decoded_length(arg[0].len));
    if (s->login.data == NULL){
        return NGX_ERROR;
    }

    if (ngx_decode_base64(&s->login, &arg[0]) != NGX_OK) {
        ngx_log_error(NGX_LOG_INFO, c->log, 0,
            "client sent invalid base64 encoding in AUTH CRAM-MD5 command");
        return NGX_MAIL_PARSE_INVALID_COMMAND;
    }

    p = s->login.data;
    last = p + s->login.len;

    while (p < last) {
        if (*p++ == ' ') {
            s->login.len = p - s->login.data - 1;
            s->passwd.len = last - p;
            s->passwd.data = p;
            break;
        }
    }

    if (s->passwd.len != 32) {
        ngx_log_error(NGX_LOG_INFO, c->log, 0,
            "client sent invalid CRAM-MD5 hash in AUTH CRAM-MD5 command");
        return NGX_MAIL_PARSE_INVALID_COMMAND;
    }

    ngx_log_debug2(NGX_LOG_DEBUG_MAIL, c->log, 0,
                   "mail auth cram-md5: \"%V\" \"%V\"", &s->login, &s->passwd);

    s->auth_method = NGX_MAIL_AUTH_CRAM_MD5;

    return NGX_DONE;
}


void
ngx_mail_send(ngx_event_t *wev)
{
    ngx_int_t                  n;
    ngx_connection_t          *c;
    ngx_mail_session_t        *s;
    ngx_mail_core_srv_conf_t  *cscf;

    c = wev->data;
    s = c->data;

    if (wev->timedout) {
        ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out");
        c->timedout = 1;
        ngx_mail_close_connection(c);
        return;
    }

    if (s->out.len == 0) {
        if (ngx_handle_write_event(c->write, 0) == NGX_ERROR) {
            ngx_mail_close_connection(c);
        }

        return;
    }

    n = c->send(c, s->out.data, s->out.len);

    if (n > 0) {
        s->out.len -= n;

        if (wev->timer_set) {
            ngx_del_timer(wev);
        }

        if (s->quit) {
            ngx_mail_close_connection(c);
            return;
        }

        if (s->blocked) {
            c->read->handler(c->read);
        }

        return;
    }

    if (n == NGX_ERROR) {
        ngx_mail_close_connection(c);
        return;
    }

    /* n == NGX_AGAIN */

    cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);

    ngx_add_timer(c->write, cscf->timeout);

    if (ngx_handle_write_event(c->write, 0) == NGX_ERROR) {
        ngx_mail_close_connection(c);
        return;
    }
}


ngx_int_t
ngx_mail_read_command(ngx_mail_session_t *s, ngx_connection_t *c)
{
    ssize_t                    n;
    ngx_int_t                  rc;
    ngx_str_t                  l;
    ngx_mail_core_srv_conf_t  *cscf;

    n = c->recv(c, s->buffer->last, s->buffer->end - s->buffer->last);

    if (n == NGX_ERROR || n == 0) {
        ngx_mail_close_connection(c);
        return NGX_ERROR;
    }

    if (n > 0) {
        s->buffer->last += n;
    }

    if (n == NGX_AGAIN) {
        if (ngx_handle_read_event(c->read, 0) == NGX_ERROR) {
            ngx_mail_session_internal_server_error(s);
            return NGX_ERROR;
        }

        return NGX_AGAIN;
    }

    cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);

    rc = cscf->protocol->parse_command(s);

    if (rc == NGX_AGAIN) {

        if (s->buffer->last < s->buffer->end) {
            return rc;
        }

        l.len = s->buffer->last - s->buffer->start;
        l.data = s->buffer->start;

        ngx_log_error(NGX_LOG_INFO, c->log, 0,
                      "client sent too long command \"%V\"", &l);

        s->quit = 1;

        return NGX_MAIL_PARSE_INVALID_COMMAND;
    }

    if (rc == NGX_IMAP_NEXT || rc == NGX_MAIL_PARSE_INVALID_COMMAND) {
        return rc;
    }

    if (rc == NGX_ERROR) {
        ngx_mail_close_connection(c);
        return NGX_ERROR;
    }

    return NGX_OK;
}


void
ngx_mail_auth(ngx_mail_session_t *s, ngx_connection_t *c)
{
    s->args.nelts = 0;
    s->buffer->pos = s->buffer->start;
    s->buffer->last = s->buffer->start;
    s->state = 0;

    if (c->read->timer_set) {
        ngx_del_timer(c->read);
    }

    s->login_attempt++;

    ngx_mail_auth_http_init(s);
}


void
ngx_mail_session_internal_server_error(ngx_mail_session_t *s)
{
    ngx_mail_core_srv_conf_t  *cscf;

    cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);

    s->out = cscf->protocol->internal_server_error;
    s->quit = 1;

    ngx_mail_send(s->connection->write);
}


void
ngx_mail_close_connection(ngx_connection_t *c)
{
    ngx_pool_t  *pool;

    ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
                   "close mail connection: %d", c->fd);

#if (NGX_MAIL_SSL)

    if (c->ssl) {
        if (ngx_ssl_shutdown(c) == NGX_AGAIN) {
            c->ssl->handler = ngx_mail_close_connection;
            return;
        }
    }

#endif

#if (NGX_STAT_STUB)
    ngx_atomic_fetch_add(ngx_stat_active, -1);
#endif

    c->destroyed = 1;

    pool = c->pool;

    ngx_close_connection(c);

    ngx_destroy_pool(pool);
}


u_char *
ngx_mail_log_error(ngx_log_t *log, u_char *buf, size_t len)
{
    u_char              *p;
    ngx_mail_session_t  *s;
    ngx_mail_log_ctx_t  *ctx;

    if (log->action) {
        p = ngx_snprintf(buf, len, " while %s", log->action);
        len -= p - buf;
        buf = p;
    }

    ctx = log->data;

    p = ngx_snprintf(buf, len, ", client: %V", ctx->client);
    len -= p - buf;
    buf = p;

    s = ctx->session;

    if (s == NULL) {
        return p;
    }

    p = ngx_snprintf(buf, len, "%s, server: %V",
                     s->starttls ? " using starttls" : "",
                     s->addr_text);
    len -= p - buf;
    buf = p;

    if (s->login.len == 0) {
        return p;
    }

    p = ngx_snprintf(buf, len, ", login: \"%V\"", &s->login);
    len -= p - buf;
    buf = p;

    if (s->proxy == NULL) {
        return p;
    }

    p = ngx_snprintf(buf, len, ", upstream: %V", s->proxy->upstream.name);

    return p;
}