flow, icmp, tcp: Clean up helpers for getting flow from index

TCP (both regular and spliced) and ICMP both have macros to retrieve the
relevant protcol specific flow structure from a flow index.  In most cases
what we actually want is to get the specific flow from a sidx.  Replace
those simple macros with a more precise inline, which also asserts that
the flow is of the type we expect.

While we're they're also add a pif_at_sidx() helper to get the interface of
a specific flow & side, which is useful in some places.

Finally, fix some minor style issues in the comments on some of the
existing sidx related helpers.

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

1 files changed, 19 insertions, 3 deletions

diff --git a/icmp.c b/icmp.c
index d4ccc72..7cf31e6 100644
--- a/icmp.c
+++ b/icmp.c
@@ -45,19 +45,35 @@
 #define ICMP_ECHO_TIMEOUT	60 /* s, timeout for ICMP socket activity */
 #define ICMP_NUM_IDS		(1U << 16)
 
-#define PINGF(idx)		(&(FLOW(idx)->ping))
-
 /* Indexed by ICMP echo identifier */
 static struct icmp_ping_flow *icmp_id_map[IP_VERSIONS][ICMP_NUM_IDS];
 
 /**
+ * ping_at_sidx() - Get ping specific flow at given sidx
+ * @sidx:	Flow and side to retrieve
+ *
+ * Return: ping specific flow at @sidx, or NULL of @sidx is invalid.  Asserts if
+ *         the flow at @sidx is not FLOW_PING4 or FLOW_PING6
+ */
+static struct icmp_ping_flow *ping_at_sidx(flow_sidx_t sidx)
+{
+	union flow *flow = flow_at_sidx(sidx);
+
+	if (!flow)
+		return NULL;
+
+	ASSERT(flow->f.type == FLOW_PING4 || flow->f.type == FLOW_PING6);
+	return &flow->ping;
+}
+
+/**
  * icmp_sock_handler() - Handle new data from ICMP or ICMPv6 socket
  * @c:		Execution context
  * @ref:	epoll reference
  */
 void icmp_sock_handler(const struct ctx *c, union epoll_ref ref)
 {
-	struct icmp_ping_flow *pingf = PINGF(ref.flowside.flow);
+	struct icmp_ping_flow *pingf = ping_at_sidx(ref.flowside);
 	union sockaddr_inany sr;
 	socklen_t sl = sizeof(sr);
 	char buf[USHRT_MAX];