[PATCH 4 of 4] QUIC: client sockets

Roman Arutyunyan arut at nginx.com
Tue Jan 17 11:24:02 UTC 2023


# HG changeset patch
# User Roman Arutyunyan <arut at nginx.com>
# Date 1673868053 0
#      Mon Jan 16 11:20:53 2023 +0000
# Branch quic
# Node ID 7873810feab00761677f02224a2f6c1b0f130203
# Parent  52681b76d4db0e9e814f1e69b0d6b35f5ac630a2
QUIC: client sockets.

In client sockets mode, a new socket is created for each client.  This socket
is bound to server address and connected to client address.  This allows for
seamless configuration reload and binary upgrade.

This mode is enabled by default and can be disabled by
"--without-quic_client_sockets" configure option.

With this approach, it is possible that some new connection packets will arrive
not to the listen socket, but to a client socket due to a race between bind()
and connect().  Such packets initiate new connections in the workers they end
up in.

diff --git a/auto/modules b/auto/modules
--- a/auto/modules
+++ b/auto/modules
@@ -1378,6 +1378,10 @@ if [ $USE_OPENSSL_QUIC = YES ]; then
 
         have=NGX_QUIC_BPF . auto/have
     fi
+
+    if [ $QUIC_CLIENT_SOCKETS = YES ]; then
+        have=NGX_QUIC_CLIENT_SOCKETS . auto/have
+    fi
 fi
 
 
diff --git a/auto/options b/auto/options
--- a/auto/options
+++ b/auto/options
@@ -45,6 +45,7 @@ USE_THREADS=NO
 
 NGX_FILE_AIO=NO
 
+QUIC_CLIENT_SOCKETS=YES
 QUIC_BPF=NO
 
 HTTP=YES
@@ -216,6 +217,7 @@ do
 
         --with-file-aio)                 NGX_FILE_AIO=YES           ;;
 
+        --without-quic_client_sockets)   QUIC_CLIENT_SOCKETS=NONE   ;;
         --without-quic_bpf_module)       QUIC_BPF=NONE              ;;
 
         --with-ipv6)
@@ -452,6 +454,7 @@ cat << END
 
   --with-file-aio                    enable file AIO support
 
+  --without-quic_client_sockets      disable QUIC client sockets
   --without-quic_bpf_module          disable ngx_quic_bpf_module
 
   --with-http_ssl_module             enable ngx_http_ssl_module
diff --git a/src/core/ngx_connection.c b/src/core/ngx_connection.c
--- a/src/core/ngx_connection.c
+++ b/src/core/ngx_connection.c
@@ -513,6 +513,33 @@ ngx_open_listening_sockets(ngx_cycle_t *
 
 #if (NGX_HAVE_REUSEPORT)
 
+#if (NGX_QUIC_CLIENT_SOCKETS && defined SO_REUSEPORT_LB)
+
+            if (ls[i].quic) {
+                int  reuseport;
+
+                reuseport = 1;
+
+                if (setsockopt(s, SOL_SOCKET, SO_REUSEPORT,
+                               (const void *) &reuseport, sizeof(int))
+                    == -1)
+                {
+                    ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno,
+                                  "setsockopt(SO_REUSEPORT) %V failed",
+                                  &ls[i].addr_text);
+
+                    if (ngx_close_socket(s) == -1) {
+                        ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno,
+                                      ngx_close_socket_n " %V failed",
+                                      &ls[i].addr_text);
+                    }
+
+                    return NGX_ERROR;
+                }
+            }
+
+#endif
+
             if (ls[i].reuseport && !ngx_test_config) {
                 int  reuseport;
 
diff --git a/src/event/quic/ngx_event_quic.c b/src/event/quic/ngx_event_quic.c
--- a/src/event/quic/ngx_event_quic.c
+++ b/src/event/quic/ngx_event_quic.c
@@ -10,11 +10,15 @@
 #include <ngx_event_quic_connection.h>
 
 
+#define NGX_QUIC_LINGERING_TIMEOUT  50
+
+
 static ngx_quic_connection_t *ngx_quic_new_connection(ngx_connection_t *c,
     ngx_quic_conf_t *conf, ngx_quic_header_t *pkt);
 static ngx_int_t ngx_quic_handle_stateless_reset(ngx_connection_t *c,
     ngx_quic_header_t *pkt);
 static void ngx_quic_input_handler(ngx_event_t *rev);
+static void ngx_quic_lingering_handler(ngx_event_t *rev);
 static void ngx_quic_close_handler(ngx_event_t *ev);
 
 static ngx_int_t ngx_quic_handle_packet(ngx_connection_t *c,
@@ -208,6 +212,13 @@ ngx_quic_run(ngx_connection_t *c, ngx_qu
         ngx_quic_close_connection(c, rc);
         return;
     }
+
+    if (!c->shared) {
+        if (ngx_add_event(c->read, NGX_READ_EVENT, 0) == NGX_ERROR) {
+            ngx_quic_close_connection(c, NGX_ERROR);
+            return;
+        }
+    }
 }
 
 
@@ -432,6 +443,10 @@ ngx_quic_input_handler(ngx_event_t *rev)
 
         return;
     }
+
+    if (!c->shared) {
+        ngx_quic_recvmsg(rev);
+    }
 }
 
 
@@ -574,6 +589,15 @@ quic_done:
 
     c->destroyed = 1;
 
+    if (c->read->ready) {
+        ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0, "quic lingering");
+
+        c->read->handler = ngx_quic_lingering_handler;
+        ngx_add_timer(c->read, NGX_QUIC_LINGERING_TIMEOUT);
+
+        return;
+    }
+
     pool = c->pool;
 
     ngx_close_connection(c);
@@ -582,6 +606,31 @@ quic_done:
 }
 
 
+static void
+ngx_quic_lingering_handler(ngx_event_t *rev)
+{
+    ngx_pool_t        *pool;
+    ngx_connection_t  *c;
+
+    c = rev->data;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0, "quic lingering handler");
+
+    if (rev->ready && !rev->timedout) {
+        ngx_quic_recvmsg(rev);
+    }
+
+    if (!rev->ready || rev->timedout) {
+        pool = c->pool;
+
+        ngx_close_connection(c);
+        ngx_destroy_pool(pool);
+
+        return;
+    }
+}
+
+
 void
 ngx_quic_finalize_connection(ngx_connection_t *c, ngx_uint_t err,
     const char *reason)
diff --git a/src/event/quic/ngx_event_quic_output.c b/src/event/quic/ngx_event_quic_output.c
--- a/src/event/quic/ngx_event_quic_output.c
+++ b/src/event/quic/ngx_event_quic_output.c
@@ -437,8 +437,10 @@ ngx_quic_send_segments(ngx_connection_t 
     msg.msg_iov = &iov;
     msg.msg_iovlen = 1;
 
-    msg.msg_name = sockaddr;
-    msg.msg_namelen = socklen;
+    if (c->shared) {
+        msg.msg_name = sockaddr;
+        msg.msg_namelen = socklen;
+    }
 
     msg.msg_control = msg_control;
     msg.msg_controllen = sizeof(msg_control);
@@ -455,7 +457,7 @@ ngx_quic_send_segments(ngx_connection_t 
     *valp = segment;
 
 #if (NGX_HAVE_ADDRINFO_CMSG)
-    if (c->listening && c->listening->wildcard && c->local_sockaddr) {
+    if (c->shared && c->listening->wildcard) {
         cmsg = CMSG_NXTHDR(&msg, cmsg);
         clen += ngx_set_srcaddr_cmsg(cmsg, c->local_sockaddr);
     }
@@ -747,11 +749,13 @@ ngx_quic_send(ngx_connection_t *c, u_cha
     msg.msg_iov = &iov;
     msg.msg_iovlen = 1;
 
-    msg.msg_name = sockaddr;
-    msg.msg_namelen = socklen;
+    if (c->shared) {
+        msg.msg_name = sockaddr;
+        msg.msg_namelen = socklen;
+    }
 
 #if (NGX_HAVE_ADDRINFO_CMSG)
-    if (c->listening && c->listening->wildcard && c->local_sockaddr) {
+    if (c->shared && c->listening->wildcard) {
 
         msg.msg_control = msg_control;
         msg.msg_controllen = sizeof(msg_control);
diff --git a/src/event/quic/ngx_event_quic_udp.c b/src/event/quic/ngx_event_quic_udp.c
--- a/src/event/quic/ngx_event_quic_udp.c
+++ b/src/event/quic/ngx_event_quic_udp.c
@@ -11,6 +11,11 @@
 #include <ngx_event_quic_connection.h>
 
 
+#if (NGX_QUIC_CLIENT_SOCKETS)
+static ngx_int_t ngx_quic_create_client_socket_connection(ngx_connection_t *lc,
+    ngx_connection_t **pc, struct sockaddr *sockaddr, socklen_t socklen,
+    struct sockaddr *local_sockaddr, socklen_t local_socklen);
+#endif
 static void ngx_quic_close_accepted_connection(ngx_connection_t *c);
 static ngx_connection_t *ngx_quic_lookup_connection(ngx_listening_t *ls,
     ngx_str_t *key, struct sockaddr *local_sockaddr, socklen_t local_socklen);
@@ -48,7 +53,6 @@ ngx_quic_recvmsg(ngx_event_t *ev)
 
     lc = ev->data;
     ls = lc->listening;
-    ev->ready = 0;
 
     ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
                    "quic recvmsg on %V, ready: %d",
@@ -65,8 +69,17 @@ ngx_quic_recvmsg(ngx_event_t *ev)
         msg.msg_iov = iov;
         msg.msg_iovlen = 1;
 
+        if (lc->local_sockaddr) {
+            local_sockaddr = lc->local_sockaddr;
+            local_socklen = lc->local_socklen;
+
+        } else {
+            local_sockaddr = ls->sockaddr;
+            local_socklen = ls->socklen;
+        }
+
 #if (NGX_HAVE_ADDRINFO_CMSG)
-        if (ls->wildcard) {
+        if (ngx_inet_wildcard(local_sockaddr)) {
             msg.msg_control = &msg_control;
             msg.msg_controllen = sizeof(msg_control);
 
@@ -82,6 +95,7 @@ ngx_quic_recvmsg(ngx_event_t *ev)
             if (err == NGX_EAGAIN) {
                 ngx_log_debug0(NGX_LOG_DEBUG_EVENT, ev->log, err,
                                "quic recvmsg() not ready");
+                ev->ready = 0;
                 return;
             }
 
@@ -121,12 +135,9 @@ ngx_quic_recvmsg(ngx_event_t *ev)
 
 #endif
 
-        local_sockaddr = ls->sockaddr;
-        local_socklen = ls->socklen;
-
 #if (NGX_HAVE_ADDRINFO_CMSG)
 
-        if (ls->wildcard) {
+        if (ngx_inet_wildcard(local_sockaddr)) {
             struct cmsghdr  *cmsg;
 
             ngx_memcpy(&lsa, local_sockaddr, local_socklen);
@@ -201,6 +212,17 @@ ngx_quic_recvmsg(ngx_event_t *ev)
         }
 #endif
 
+#if (NGX_QUIC_CLIENT_SOCKETS)
+        if (c == NULL) {
+            if (ngx_quic_create_client_socket_connection(lc, &c,
+                              sockaddr, socklen, local_sockaddr, local_socklen)
+                != NGX_OK)
+            {
+                return;
+            }
+        }
+#endif
+
         if (c == NULL) {
             c = ngx_get_connection(lc->fd, ev->log);
             if (c == NULL) {
@@ -243,17 +265,13 @@ ngx_quic_recvmsg(ngx_event_t *ev)
         c->pool->log = log;
         c->listening = ls;
 
-        if (local_sockaddr == &lsa.sockaddr) {
-            local_sockaddr = ngx_palloc(c->pool, local_socklen);
-            if (local_sockaddr == NULL) {
-                ngx_quic_close_accepted_connection(c);
-                return;
-            }
-
-            ngx_memcpy(local_sockaddr, &lsa, local_socklen);
+        c->local_sockaddr = ngx_palloc(c->pool, local_socklen);
+        if (c->local_sockaddr == NULL) {
+            ngx_quic_close_accepted_connection(c);
+            return;
         }
 
-        c->local_sockaddr = local_sockaddr;
+        ngx_memcpy(c->local_sockaddr, local_sockaddr, local_socklen);
         c->local_socklen = local_socklen;
 
         c->buffer = ngx_create_temp_buf(c->pool, n);
@@ -267,7 +285,7 @@ ngx_quic_recvmsg(ngx_event_t *ev)
         rev = c->read;
         wev = c->write;
 
-        rev->active = 1;
+        rev->ready = (c->shared ? 0 : 1);
         wev->ready = 1;
 
         rev->log = log;
@@ -341,6 +359,94 @@ ngx_quic_recvmsg(ngx_event_t *ev)
 }
 
 
+#if (NGX_QUIC_CLIENT_SOCKETS)
+
+static ngx_int_t
+ngx_quic_create_client_socket_connection(ngx_connection_t *lc,
+    ngx_connection_t **pc, struct sockaddr *sockaddr, socklen_t socklen,
+    struct sockaddr *local_sockaddr, socklen_t local_socklen)
+{
+    int           value;
+    ngx_socket_t  s;
+
+    s = ngx_socket(sockaddr->sa_family, SOCK_DGRAM, 0);
+    if (s == (ngx_socket_t) -1) {
+        ngx_log_error(NGX_LOG_ERR, lc->log, ngx_socket_errno,
+                      ngx_socket_n " failed");
+        return NGX_ERROR;
+    }
+
+    if (ngx_nonblocking(s) == -1) {
+        ngx_log_error(NGX_LOG_EMERG, lc->log, ngx_socket_errno,
+                      ngx_nonblocking_n " client socket failed");
+        goto failed;
+    }
+
+    value = 1;
+
+#if (NGX_HAVE_REUSEPORT && !NGX_LINUX)
+
+    if (setsockopt(s, SOL_SOCKET, SO_REUSEPORT,
+                   (const void *) &value, sizeof(int))
+        == -1)
+    {
+        ngx_log_error(NGX_LOG_EMERG, lc->log, ngx_socket_errno,
+                      "setsockopt(SO_REUSEPORT) client socket failed");
+        goto failed;
+    }
+
+#else
+
+    if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
+                   (const void *) &value, sizeof(int))
+        == -1)
+    {
+        ngx_log_error(NGX_LOG_EMERG, lc->log, ngx_socket_errno,
+                      "setsockopt(SO_REUSEADDR) client socket failed");
+        goto failed;
+    }
+
+#endif
+
+    if (bind(s, local_sockaddr, local_socklen) == -1) {
+        ngx_log_error(NGX_LOG_EMERG, lc->log, ngx_socket_errno,
+                      "bind() for client socket failed");
+        goto failed;
+    }
+
+    if (connect(s, sockaddr, socklen) == -1) {
+        ngx_log_error(NGX_LOG_EMERG, lc->log, ngx_socket_errno,
+                      "connect() to client failed");
+        goto failed;
+    }
+
+    *pc = ngx_get_connection(s, lc->log);
+    if (*pc == NULL) {
+        goto failed;
+    }
+
+    ngx_log_debug2(NGX_LOG_DEBUG_EVENT, lc->log, 0,
+                   "quic client socket connection fd:%d r:%d",
+                   s, lc->listening->connection != lc);
+
+    ngx_accept_disabled = ngx_cycle->connection_n / 8
+                          - ngx_cycle->free_connection_n;
+
+    return NGX_OK;
+
+failed:
+
+    if (ngx_close_socket(s) == -1) {
+        ngx_log_error(NGX_LOG_EMERG, lc->log, ngx_socket_errno,
+                      ngx_close_socket_n " client failed");
+    }
+
+    return NGX_ERROR;
+}
+
+#endif
+
+
 static void
 ngx_quic_close_accepted_connection(ngx_connection_t *c)
 {


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