flow, tcp: Consolidate flow pointer<->index helpers

Both tcp.c and tcp_splice.c define CONN_IDX() variants to find the index
of their connection structures in the connection table, now become the
unified flow table.  We can easily combine these into a common helper.
While we're there, add some trickery for some additional type safety.

They also define their own CONN() versions, which aren't so easily combined
since they need to return different types, but we can have them use a
common helper.

In the process, we standardise on always using an unsigned type to store
the connection / flow index, which makes more sense.  tcp.c's conn_at_idx()
remains for now, but we change its parameter to unsigned to match.  That in
turn means we can remove a check for negative values from it.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 10 insertions, 11 deletions

diff --git a/tcp_splice.c b/tcp_splice.c
index 092a816..4b5c81a 100644
--- a/tcp_splice.c
+++ b/tcp_splice.c
@@ -76,8 +76,7 @@ static int splice_pipe_pool		[TCP_SPLICE_PIPE_POOL_SIZE][2];
 #define CONN_V6(x)			(x->flags & SPLICE_V6)
 #define CONN_V4(x)			(!CONN_V6(x))
 #define CONN_HAS(conn, set)		((conn->events & (set)) == (set))
-#define CONN(idx)			(&tc[(idx)].splice)
-#define CONN_IDX(conn)			((union flow *)(conn) - flowtab)
+#define CONN(idx)			(&FLOW(idx)->tcp_splice)
 
 /* Display strings for connection events */
 static const char *tcp_splice_event_str[] __attribute((__unused__)) = {
@@ -129,8 +128,8 @@ static int tcp_splice_epoll_ctl(const struct ctx *c,
 {
 	int m = conn->in_epoll ? EPOLL_CTL_MOD : EPOLL_CTL_ADD;
 	union epoll_ref ref[SIDES] = {
-		{ .type = EPOLL_TYPE_TCP, .fd = conn->s[0], .tcp.index = CONN_IDX(conn) },
-		{ .type = EPOLL_TYPE_TCP, .fd = conn->s[1], .tcp.index = CONN_IDX(conn) }
+		{ .type = EPOLL_TYPE_TCP, .fd = conn->s[0], .tcp.index = FLOW_IDX(conn) },
+		{ .type = EPOLL_TYPE_TCP, .fd = conn->s[1], .tcp.index = FLOW_IDX(conn) }
 	};
 	struct epoll_event ev[SIDES] = { { .data.u64 = ref[0].u64 },
 					 { .data.u64 = ref[1].u64 } };
@@ -140,8 +139,8 @@ static int tcp_splice_epoll_ctl(const struct ctx *c,
 	if (epoll_ctl(c->epollfd, m, conn->s[0], &ev[0]) ||
 	    epoll_ctl(c->epollfd, m, conn->s[1], &ev[1])) {
 		int ret = -errno;
-		err("TCP (spliced): index %li, ERROR on epoll_ctl(): %s",
-		    CONN_IDX(conn), strerror(errno));
+		err("TCP (spliced): index %u, ERROR on epoll_ctl(): %s",
+		    FLOW_IDX(conn), strerror(errno));
 		return ret;
 	}
 
@@ -167,7 +166,7 @@ static void conn_flag_do(const struct ctx *c, struct tcp_splice_conn *conn,
 
 		conn->flags &= flag;
 		if (flag_index >= 0) {
-			debug("TCP (spliced): index %li: %s dropped", CONN_IDX(conn),
+			debug("TCP (spliced): index %u: %s dropped", FLOW_IDX(conn),
 			      tcp_splice_flag_str[flag_index]);
 		}
 	} else {
@@ -178,7 +177,7 @@ static void conn_flag_do(const struct ctx *c, struct tcp_splice_conn *conn,
 
 		conn->flags |= flag;
 		if (flag_index >= 0) {
-			debug("TCP (spliced): index %li: %s", CONN_IDX(conn),
+			debug("TCP (spliced): index %u: %s", FLOW_IDX(conn),
 			      tcp_splice_flag_str[flag_index]);
 		}
 	}
@@ -213,7 +212,7 @@ static void conn_event_do(const struct ctx *c, struct tcp_splice_conn *conn,
 
 		conn->events &= event;
 		if (flag_index >= 0) {
-			debug("TCP (spliced): index %li, ~%s", CONN_IDX(conn),
+			debug("TCP (spliced): index %u, ~%s", FLOW_IDX(conn),
 			      tcp_splice_event_str[flag_index]);
 		}
 	} else {
@@ -224,7 +223,7 @@ static void conn_event_do(const struct ctx *c, struct tcp_splice_conn *conn,
 
 		conn->events |= event;
 		if (flag_index >= 0) {
-			debug("TCP (spliced): index %li, %s", CONN_IDX(conn),
+			debug("TCP (spliced): index %u, %s", FLOW_IDX(conn),
 			      tcp_splice_event_str[flag_index]);
 		}
 	}
@@ -282,7 +281,7 @@ void tcp_splice_destroy(struct ctx *c, union flow *flow)
 
 	conn->events = SPLICE_CLOSED;
 	conn->flags = 0;
-	debug("TCP (spliced): index %li, CLOSED", CONN_IDX(conn));
+	debug("TCP (spliced): index %u, CLOSED", FLOW_IDX(conn));
 
 	tcp_table_compact(c, flow);
 }