# HG changeset patch
# User Vladimir Homutov <vl@nginx.com>
# Date 1617379099 -10800
# Node ID c61fcdc1b8e3333653868b4ac545b487484c75bb
# Parent  385d511b50641957dc09f8345d9ca3aab72ed982
UDP: extended datagram context.

Sometimes it is required to process datagram properties at higher level (i.e.
QUIC is interested in source address which may change and IP options).  The
patch adds ngx_udp_dgram_t structure used to pass packet-related information
in c->udp.

diff --git a/src/event/ngx_event.h b/src/event/ngx_event.h
--- a/src/event/ngx_event.h
+++ b/src/event/ngx_event.h
@@ -169,11 +169,18 @@ struct ngx_event_aio_s {
 
 #if !(NGX_WIN32)
 
+typedef struct {
+    ngx_buf_t                 *buffer;
+    struct sockaddr           *sockaddr;
+    socklen_t                  socklen;
+} ngx_udp_dgram_t;
+
+
 struct ngx_udp_connection_s {
     ngx_rbtree_node_t          node;
     ngx_connection_t          *connection;
     ngx_str_t                  key;
-    ngx_buf_t                 *buffer;
+    ngx_udp_dgram_t           *dgram;
 };
 
 #endif
diff --git a/src/event/ngx_event_udp.c b/src/event/ngx_event_udp.c
--- a/src/event/ngx_event_udp.c
+++ b/src/event/ngx_event_udp.c
@@ -29,12 +29,13 @@ ngx_event_recvmsg(ngx_event_t *ev)
     ngx_buf_t          buf;
     ngx_log_t         *log;
     ngx_err_t          err;
-    socklen_t          socklen, local_socklen;
+    socklen_t          local_socklen;
     ngx_event_t       *rev, *wev;
     struct iovec       iov[1];
     struct msghdr      msg;
     ngx_sockaddr_t     sa, lsa;
-    struct sockaddr   *sockaddr, *local_sockaddr;
+    ngx_udp_dgram_t    dgram;
+    struct sockaddr   *local_sockaddr;
     ngx_listening_t   *ls;
     ngx_event_conf_t  *ecf;
     ngx_connection_t  *c, *lc;
@@ -131,21 +132,21 @@ ngx_event_recvmsg(ngx_event_t *ev)
         }
 #endif
 
-        sockaddr = msg.msg_name;
-        socklen = msg.msg_namelen;
+        dgram.sockaddr = msg.msg_name;
+        dgram.socklen = msg.msg_namelen;
 
-        if (socklen > (socklen_t) sizeof(ngx_sockaddr_t)) {
-            socklen = sizeof(ngx_sockaddr_t);
+        if (dgram.socklen > (socklen_t) sizeof(ngx_sockaddr_t)) {
+            dgram.socklen = sizeof(ngx_sockaddr_t);
         }
 
-        if (socklen == 0) {
+        if (dgram.socklen == 0) {
 
             /*
              * on Linux recvmsg() returns zero msg_namelen
              * when receiving packets from unbound AF_UNIX sockets
              */
 
-            socklen = sizeof(struct sockaddr);
+            dgram.socklen = sizeof(struct sockaddr);
             ngx_memzero(&sa, sizeof(struct sockaddr));
             sa.sockaddr.sa_family = ls->sockaddr->sa_family;
         }
@@ -223,15 +224,16 @@ ngx_event_recvmsg(ngx_event_t *ev)
 
 #endif
 
-        key.data = (u_char *) sockaddr;
-        key.len = socklen;
+        key.data = (u_char *) dgram.sockaddr;
+        key.len = dgram.socklen;
 
 #if (NGX_HAVE_UNIX_DOMAIN)
 
-        if (sockaddr->sa_family == AF_UNIX) {
-            struct sockaddr_un *saun = (struct sockaddr_un *) sockaddr;
+        if (dgram.sockaddr->sa_family == AF_UNIX) {
+            struct sockaddr_un *saun = (struct sockaddr_un *) dgram.sockaddr;
 
-            if (socklen <= (socklen_t) offsetof(struct sockaddr_un, sun_path)
+            if (dgram.socklen <= (socklen_t) offsetof(struct sockaddr_un,
+                                                      sun_path)
                 || saun->sun_path[0] == '\0')
             {
                 ngx_log_debug0(NGX_LOG_DEBUG_EVENT, ngx_cycle->log, 0,
@@ -268,13 +270,6 @@ ngx_event_recvmsg(ngx_event_t *ev)
             }
 #endif
 
-#if (NGX_QUIC)
-            if (ls->quic) {
-                c->socklen = socklen;
-                ngx_memcpy(c->sockaddr, sockaddr, socklen);
-            }
-#endif
-
             ngx_memzero(&buf, sizeof(ngx_buf_t));
 
             buf.pos = buffer;
@@ -284,7 +279,9 @@ ngx_event_recvmsg(ngx_event_t *ev)
 
             rev = c->read;
 
-            c->udp->buffer = &buf;
+            dgram.buffer = &buf;
+
+            c->udp->dgram = &dgram;
 
             rev->ready = 1;
             rev->active = 0;
@@ -292,7 +289,7 @@ ngx_event_recvmsg(ngx_event_t *ev)
             rev->handler(rev);
 
             if (c->udp) {
-                c->udp->buffer = NULL;
+                c->udp->dgram = NULL;
             }
 
             rev->ready = 0;
@@ -315,7 +312,7 @@ ngx_event_recvmsg(ngx_event_t *ev)
 
         c->shared = 1;
         c->type = SOCK_DGRAM;
-        c->socklen = socklen;
+        c->socklen = dgram.socklen;
 
 #if (NGX_STAT_STUB)
         (void) ngx_atomic_fetch_add(ngx_stat_active, 1);
@@ -327,7 +324,7 @@ ngx_event_recvmsg(ngx_event_t *ev)
             return;
         }
 
-        len = socklen;
+        len = dgram.socklen;
 
 #if (NGX_QUIC)
         if (ls->quic) {
@@ -341,7 +338,7 @@ ngx_event_recvmsg(ngx_event_t *ev)
             return;
         }
 
-        ngx_memcpy(c->sockaddr, sockaddr, socklen);
+        ngx_memcpy(c->sockaddr, dgram.sockaddr, dgram.socklen);
 
         log = ngx_palloc(c->pool, sizeof(ngx_log_t));
         if (log == NULL) {
@@ -483,17 +480,17 @@ ngx_udp_shared_recv(ngx_connection_t *c,
     ssize_t     n;
     ngx_buf_t  *b;
 
-    if (c->udp == NULL || c->udp->buffer == NULL) {
+    if (c->udp == NULL || c->udp->dgram == NULL) {
         return NGX_AGAIN;
     }
 
-    b = c->udp->buffer;
+    b = c->udp->dgram->buffer;
 
     n = ngx_min(b->last - b->pos, (ssize_t) size);
 
     ngx_memcpy(buf, b->pos, n);
 
-    c->udp->buffer = NULL;
+    c->udp->dgram = NULL;
 
     c->read->ready = 0;
     c->read->active = 1;
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
@@ -1920,7 +1920,7 @@ ngx_quic_input_handler(ngx_event_t *rev)
         }
     }
 
-    b = c->udp->buffer;
+    b = c->udp->dgram->buffer;
 
     qc->received += (b->last - b->pos);