treewide: Packet abstraction with mandatory boundary checks

Implement a packet abstraction providing boundary and size checks
based on packet descriptors: packets stored in a buffer can be queued
into a pool (without storage of its own), and data can be retrieved
referring to an index in the pool, specifying offset and length.

Checks ensure data is not read outside the boundaries of buffer and
descriptors, and that packets added to a pool are within the buffer
range with valid offset and indices.

This implies a wider rework: usage of the "queueing" part of the
abstraction mostly affects tap_handler_{passt,pasta}() functions and
their callees, while the "fetching" part affects all the guest or tap
facing implementations: TCP, UDP, ICMP, ARP, NDP, DHCP and DHCPv6
handlers.

Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 5 insertions, 11 deletions

diff --git a/tcp.h b/tcp.h
index 109516d..cf52f32 100644
--- a/tcp.h
+++ b/tcp.h
@@ -6,9 +6,7 @@
 #ifndef TCP_H
 #define TCP_H
 
-#define REFILL_INTERVAL			1000	/* ms */
-#define PORT_DETECT_INTERVAL		1000
-#define TCP_TIMER_INTERVAL	MIN(REFILL_INTERVAL, PORT_DETECT_INTERVAL)
+#define TCP_TIMER_INTERVAL		1000	/* ms */
 
 #define TCP_CONN_INDEX_BITS		17	/* 128k */
 #define TCP_MAX_CONNS			(1 << TCP_CONN_INDEX_BITS)
@@ -20,10 +18,10 @@ struct ctx;
 
 void tcp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events,
 		      struct timespec *now);
-int tcp_tap_handler(struct ctx *c, int af, void *addr,
-		    struct tap_l4_msg *msg, int count, struct timespec *now);
-int tcp_sock_init(struct ctx *c, struct timespec *now);
-void tcp_timer(struct ctx *c, struct timespec *now);
+int tcp_tap_handler(struct ctx *c, int af, void *addr, struct pool *p,
+		    struct timespec *now);
+int tcp_sock_init(struct ctx *c);
+void tcp_timer(struct ctx *c, struct timespec *ts);
 void tcp_defer_handler(struct ctx *c);
 
 void tcp_sock_set_bufsize(struct ctx *c, int s);
@@ -64,8 +62,6 @@ union tcp_epoll_ref {
  * @timer_run:		Timestamp of most recent timer run
  * @kernel_snd_wnd:	Kernel reports sending window (with commit 8f7baad7f035)
  * @pipe_size:		Size of pipes for spliced connections
- * @refill_ts:		Time of last refill operation for pools of sockets/pipes
- * @port_detect_ts:	Time of last TCP port detection/rebind, if enabled
  */
 struct tcp_ctx {
 	uint64_t hash_secret[2];
@@ -80,8 +76,6 @@ struct tcp_ctx {
 	int kernel_snd_wnd;
 #endif
 	size_t pipe_size;
-	struct timespec refill_ts;
-	struct timespec port_detect_ts;
 };
 
 #endif /* TCP_H */