udp, passt: Introduce socket packet buffer, avoid getsockname() for UDP

This is in preparation for scatter-gather IO on the UDP receive path:
save a getsockname() syscall by setting a flag if we get the numbering
of all bound sockets in a strict sequence (expected, in practice) and
repurpose the tap buffer to be also a socket receive buffer, passing
it down to protocol handlers.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/udp.h b/udp.h
index 201714a..a126488 100644
--- a/udp.h
+++ b/udp.h
@@ -3,7 +3,7 @@
 
 #define UDP_TIMER_INTERVAL		1000 /* ms */
 
-void udp_sock_handler(struct ctx *c, int s, uint32_t events,
+void udp_sock_handler(struct ctx *c, int s, uint32_t events, char *pkt_buf,
 		      struct timespec *now);
 int udp_tap_handler(struct ctx *c, int af, void *addr,
 		    struct tap_msg *msg, int count, struct timespec *now);
@@ -14,11 +14,13 @@ void udp_timer(struct ctx *c, struct timespec *ts);
  * struct udp_ctx - Execution context for UDP
  * @fd_min:		Lowest file descriptor number for UDP ever used
  * @fd_max:		Highest file descriptor number for UDP ever used
+ * @fd_in_seq:		1 if all socket numbers are in sequence, 0 otherwise
  * @timer_run:		Timestamp of most recent timer run
  */
 struct udp_ctx {
 	int fd_min;
 	int fd_max;
+	int fd_in_seq;
 	struct timespec timer_run;
 };