Mercurial > hg > nginx
view src/mail/ngx_mail_handler.c @ 9260:ac5635650bc6
Request body: handling of body after unbuffered reading.
As long as unbuffered reading of the request body was used, and an attempt
to read the request body is made again, such as when redirecting the request
to an error page, the request body is now cleared to make sure it can be
used safely.
Further, the r->reading_body flag, if it is still set, is cleared (along with
disabling keepalive and enabling lingering close), so the code which uses
the request body, such as when proxying, is not confused and doesn't try
to use "Transfer-Encoding: chunked".
Note that this change makes the workaround for HTTP/2 issues with unbuffered
proxying and error pages, as introduced in 7561:9f1f9d6e056a, ineffective
(since r->reading_body now cleared along with r->reading_body_no_buffering).
Though the workaround is anyway not needed after 7924:d9e009b39596, hence
it is removed.
This makes it safer to use complex processing of error pages with unbuffered
proxying.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Sat, 27 Apr 2024 18:22:07 +0300 |
parents | d9a52ebb9b00 |
children | f83cb031a4a4 |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #include <ngx_mail.h> static void ngx_mail_proxy_protocol_handler(ngx_event_t *rev); static void ngx_mail_init_session_handler(ngx_event_t *rev); static void ngx_mail_init_session(ngx_connection_t *c); #if (NGX_MAIL_SSL) static void ngx_mail_ssl_init_connection(ngx_ssl_t *ssl, ngx_connection_t *c); static void ngx_mail_ssl_handshake_handler(ngx_connection_t *c); static ngx_int_t ngx_mail_verify_cert(ngx_mail_session_t *s, ngx_connection_t *c); #endif void ngx_mail_init_connection(ngx_connection_t *c) { size_t len; ngx_uint_t i; ngx_event_t *rev; ngx_mail_port_t *port; struct sockaddr *sa; struct sockaddr_in *sin; ngx_mail_log_ctx_t *ctx; ngx_mail_in_addr_t *addr; ngx_mail_session_t *s; ngx_mail_addr_conf_t *addr_conf; ngx_mail_core_srv_conf_t *cscf; u_char text[NGX_SOCKADDR_STRLEN]; #if (NGX_HAVE_INET6) struct sockaddr_in6 *sin6; ngx_mail_in6_addr_t *addr6; #endif /* find the server configuration for the address:port */ port = c->listening->servers; if (port->naddrs > 1) { /* * There are several addresses on this port and one of them * is the "*:port" wildcard so getsockname() is needed to determine * the server address. * * AcceptEx() already gave this address. */ if (ngx_connection_local_sockaddr(c, NULL, 0) != NGX_OK) { ngx_mail_close_connection(c); return; } sa = c->local_sockaddr; switch (sa->sa_family) { #if (NGX_HAVE_INET6) case AF_INET6: sin6 = (struct sockaddr_in6 *) sa; addr6 = port->addrs; /* the last address is "*" */ for (i = 0; i < port->naddrs - 1; i++) { if (ngx_memcmp(&addr6[i].addr6, &sin6->sin6_addr, 16) == 0) { break; } } addr_conf = &addr6[i].conf; break; #endif default: /* AF_INET */ sin = (struct sockaddr_in *) sa; addr = port->addrs; /* the last address is "*" */ for (i = 0; i < port->naddrs - 1; i++) { if (addr[i].addr == sin->sin_addr.s_addr) { break; } } addr_conf = &addr[i].conf; break; } } else { switch (c->local_sockaddr->sa_family) { #if (NGX_HAVE_INET6) case AF_INET6: addr6 = port->addrs; addr_conf = &addr6[0].conf; break; #endif default: /* AF_INET */ addr = port->addrs; addr_conf = &addr[0].conf; break; } } s = ngx_pcalloc(c->pool, sizeof(ngx_mail_session_t)); if (s == NULL) { ngx_mail_close_connection(c); return; } s->signature = NGX_MAIL_MODULE; s->main_conf = addr_conf->ctx->main_conf; s->srv_conf = addr_conf->ctx->srv_conf; #if (NGX_MAIL_SSL) s->ssl = addr_conf->ssl; #endif s->addr_text = &addr_conf->addr_text; c->data = s; s->connection = c; cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); ngx_set_connection_log(c, cscf->error_log); len = ngx_sock_ntop(c->sockaddr, c->socklen, text, NGX_SOCKADDR_STRLEN, 1); ngx_log_error(NGX_LOG_INFO, c->log, 0, "*%uA client %*s connected to %V", c->number, len, text, s->addr_text); ctx = ngx_palloc(c->pool, sizeof(ngx_mail_log_ctx_t)); if (ctx == NULL) { ngx_mail_close_connection(c); return; } ctx->client = &c->addr_text; ctx->session = s; c->log->connection = c->number; c->log->handler = ngx_mail_log_error; c->log->data = ctx; c->log->action = "sending client greeting line"; c->log_error = NGX_ERROR_INFO; rev = c->read; rev->handler = ngx_mail_init_session_handler; if (addr_conf->proxy_protocol) { c->log->action = "reading PROXY protocol"; rev->handler = ngx_mail_proxy_protocol_handler; if (!rev->ready) { ngx_add_timer(rev, cscf->timeout); if (ngx_handle_read_event(rev, 0) != NGX_OK) { ngx_mail_close_connection(c); } return; } } if (ngx_use_accept_mutex) { ngx_post_event(rev, &ngx_posted_events); return; } rev->handler(rev); } static void ngx_mail_proxy_protocol_handler(ngx_event_t *rev) { u_char *p, buf[NGX_PROXY_PROTOCOL_MAX_HEADER]; size_t size; ssize_t n; ngx_err_t err; ngx_connection_t *c; ngx_mail_session_t *s; ngx_mail_core_srv_conf_t *cscf; c = rev->data; s = c->data; ngx_log_debug0(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail PROXY protocol handler"); if (rev->timedout) { ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out"); c->timedout = 1; ngx_mail_close_connection(c); return; } n = recv(c->fd, (char *) buf, sizeof(buf), MSG_PEEK); err = ngx_socket_errno; ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "recv(): %z", n); if (n == -1) { if (err == NGX_EAGAIN) { rev->ready = 0; if (!rev->timer_set) { cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); ngx_add_timer(rev, cscf->timeout); } if (ngx_handle_read_event(rev, 0) != NGX_OK) { ngx_mail_close_connection(c); } return; } ngx_connection_error(c, err, "recv() failed"); ngx_mail_close_connection(c); return; } p = ngx_proxy_protocol_read(c, buf, buf + n); if (p == NULL) { ngx_mail_close_connection(c); return; } size = p - buf; if (c->recv(c, buf, size) != (ssize_t) size) { ngx_mail_close_connection(c); return; } if (ngx_mail_realip_handler(s) != NGX_OK) { ngx_mail_close_connection(c); return; } ngx_mail_init_session_handler(rev); } static void ngx_mail_init_session_handler(ngx_event_t *rev) { ngx_connection_t *c; c = rev->data; #if (NGX_MAIL_SSL) { ngx_mail_session_t *s; ngx_mail_ssl_conf_t *sslcf; s = c->data; if (s->ssl) { c->log->action = "SSL handshaking"; sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module); ngx_mail_ssl_init_connection(&sslcf->ssl, c); return; } } #endif ngx_mail_init_session(c); } #if (NGX_MAIL_SSL) void ngx_mail_starttls_handler(ngx_event_t *rev) { ngx_connection_t *c; ngx_mail_session_t *s; ngx_mail_ssl_conf_t *sslcf; c = rev->data; s = c->data; s->starttls = 1; c->log->action = "in starttls state"; sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module); ngx_mail_ssl_init_connection(&sslcf->ssl, c); } static void ngx_mail_ssl_init_connection(ngx_ssl_t *ssl, ngx_connection_t *c) { ngx_mail_session_t *s; ngx_mail_core_srv_conf_t *cscf; if (ngx_ssl_create_connection(ssl, c, 0) != NGX_OK) { ngx_mail_close_connection(c); return; } if (ngx_ssl_handshake(c) == NGX_AGAIN) { s = c->data; if (!c->read->timer_set) { cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); ngx_add_timer(c->read, cscf->timeout); } c->ssl->handler = ngx_mail_ssl_handshake_handler; return; } ngx_mail_ssl_handshake_handler(c); } static void ngx_mail_ssl_handshake_handler(ngx_connection_t *c) { ngx_mail_session_t *s; ngx_mail_core_srv_conf_t *cscf; if (c->ssl->handshaked) { s = c->data; if (ngx_mail_verify_cert(s, c) != NGX_OK) { return; } if (s->starttls) { cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); c->read->handler = cscf->protocol->init_protocol; c->write->handler = ngx_mail_send; cscf->protocol->init_protocol(c->read); return; } c->read->ready = 0; ngx_mail_init_session(c); return; } ngx_mail_close_connection(c); } static ngx_int_t ngx_mail_verify_cert(ngx_mail_session_t *s, ngx_connection_t *c) { long rc; X509 *cert; ngx_mail_ssl_conf_t *sslcf; ngx_mail_core_srv_conf_t *cscf; sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module); if (!sslcf->verify) { return NGX_OK; } rc = SSL_get_verify_result(c->ssl->connection); if (rc != X509_V_OK && (sslcf->verify != 3 || !ngx_ssl_verify_error_optional(rc))) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client SSL certificate verify error: (%l:%s)", rc, X509_verify_cert_error_string(rc)); ngx_ssl_remove_cached_session(c->ssl->session_ctx, (SSL_get0_session(c->ssl->connection))); cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); s->out = cscf->protocol->cert_error; s->quit = 1; c->write->handler = ngx_mail_send; ngx_mail_send(s->connection->write); return NGX_ERROR; } if (sslcf->verify == 1) { cert = SSL_get_peer_certificate(c->ssl->connection); if (cert == NULL) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent no required SSL certificate"); ngx_ssl_remove_cached_session(c->ssl->session_ctx, (SSL_get0_session(c->ssl->connection))); cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); s->out = cscf->protocol->no_cert; s->quit = 1; c->write->handler = ngx_mail_send; ngx_mail_send(s->connection->write); return NGX_ERROR; } X509_free(cert); } return NGX_OK; } #endif static void ngx_mail_init_session(ngx_connection_t *c) { ngx_mail_session_t *s; ngx_mail_core_srv_conf_t *cscf; s = c->data; c->log->action = "sending client greeting line"; cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); s->protocol = cscf->protocol->type; s->ctx = ngx_pcalloc(c->pool, sizeof(void *) * ngx_mail_max_module); if (s->ctx == NULL) { ngx_mail_session_internal_server_error(s); return; } c->write->handler = ngx_mail_send; cscf->protocol->init_session(s, c); } ngx_int_t ngx_mail_salt(ngx_mail_session_t *s, ngx_connection_t *c, ngx_mail_core_srv_conf_t *cscf) { s->salt.data = ngx_pnalloc(c->pool, sizeof(" <18446744073709551616.@>" CRLF) - 1 + NGX_TIME_T_LEN + cscf->server_name.len); if (s->salt.data == NULL) { return NGX_ERROR; } s->salt.len = ngx_sprintf(s->salt.data, "<%ul.%T@%V>" CRLF, ngx_random(), ngx_time(), &cscf->server_name) - s->salt.data; return NGX_OK; } #if (NGX_MAIL_SSL) ngx_int_t ngx_mail_starttls_only(ngx_mail_session_t *s, ngx_connection_t *c) { ngx_mail_ssl_conf_t *sslcf; if (c->ssl) { return 0; } sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module); if (sslcf->starttls == NGX_MAIL_STARTTLS_ONLY) { return 1; } return 0; } #endif ngx_int_t ngx_mail_auth_plain(ngx_mail_session_t *s, ngx_connection_t *c, ngx_uint_t n) { u_char *p, *last; ngx_str_t *arg, plain; arg = s->args.elts; #if (NGX_DEBUG_MAIL_PASSWD) ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth plain: \"%V\"", &arg[n]); #endif plain.data = ngx_pnalloc(c->pool, ngx_base64_decoded_length(arg[n].len)); if (plain.data == NULL) { return NGX_ERROR; } if (ngx_decode_base64(&plain, &arg[n]) != NGX_OK) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent invalid base64 encoding in AUTH PLAIN command"); return NGX_MAIL_PARSE_INVALID_COMMAND; } p = plain.data; last = p + plain.len; while (p < last && *p++) { /* void */ } if (p == last) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent invalid login in AUTH PLAIN command"); return NGX_MAIL_PARSE_INVALID_COMMAND; } s->login.data = p; while (p < last && *p) { p++; } if (p == last) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent invalid password in AUTH PLAIN command"); return NGX_MAIL_PARSE_INVALID_COMMAND; } s->login.len = p++ - s->login.data; s->passwd.len = last - p; s->passwd.data = p; #if (NGX_DEBUG_MAIL_PASSWD) ngx_log_debug2(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth plain: \"%V\" \"%V\"", &s->login, &s->passwd); #endif return NGX_DONE; } ngx_int_t ngx_mail_auth_login_username(ngx_mail_session_t *s, ngx_connection_t *c, ngx_uint_t n) { ngx_str_t *arg; arg = s->args.elts; ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth login username: \"%V\"", &arg[n]); s->login.data = ngx_pnalloc(c->pool, ngx_base64_decoded_length(arg[n].len)); if (s->login.data == NULL) { return NGX_ERROR; } if (ngx_decode_base64(&s->login, &arg[n]) != 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; } 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_pnalloc(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_pnalloc(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_pnalloc(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; } ngx_int_t ngx_mail_auth_external(ngx_mail_session_t *s, ngx_connection_t *c, ngx_uint_t n) { ngx_str_t *arg, external; arg = s->args.elts; ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth external: \"%V\"", &arg[n]); external.data = ngx_pnalloc(c->pool, ngx_base64_decoded_length(arg[n].len)); if (external.data == NULL) { return NGX_ERROR; } if (ngx_decode_base64(&external, &arg[n]) != NGX_OK) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent invalid base64 encoding in AUTH EXTERNAL command"); return NGX_MAIL_PARSE_INVALID_COMMAND; } s->login.len = external.len; s->login.data = external.data; ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth external: \"%V\"", &s->login); s->auth_method = NGX_MAIL_AUTH_EXTERNAL; 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_OK) { ngx_mail_close_connection(c); } return; } n = c->send(c, s->out.data, s->out.len); if (n > 0) { s->out.data += n; s->out.len -= n; if (s->out.len != 0) { goto again; } if (wev->timer_set) { ngx_del_timer(wev); } if (s->quit) { ngx_mail_close_connection(c); return; } if (s->blocked) { ngx_post_event(c->read, &ngx_posted_events); } return; } if (n == NGX_ERROR) { ngx_mail_close_connection(c); return; } /* n == NGX_AGAIN */ 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_OK) { 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; if (s->buffer->last < s->buffer->end) { 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 (s->buffer->pos == s->buffer->last) { 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_MAIL_PARSE_INVALID_COMMAND) { s->errors++; if (s->errors >= cscf->max_errors) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent too many invalid commands"); s->quit = 1; } return rc; } if (rc == NGX_IMAP_NEXT) { return rc; } if (rc == NGX_ERROR) { ngx_mail_close_connection(c); return NGX_ERROR; } s->commands++; if (s->commands > cscf->max_commands) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent too many commands"); s->quit = 1; return NGX_MAIL_PARSE_INVALID_COMMAND; } return NGX_OK; } void ngx_mail_auth(ngx_mail_session_t *s, ngx_connection_t *c) { s->args.nelts = 0; if (s->buffer->pos == s->buffer->last) { 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) (void) 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; }