[PATCH v4 24/28] icmp: use iov_tail rather than pool

[Laurent Vivier <lvivier@redhat.com>]

As the iov_tail has a non zero offset (because of the presence of
packet headers in the iov array), we must copy it to a new
iov array (using iov_splice()) to pass it to sendmsg().

We cannot use anymore iov_tail_msghdr(), so remove it.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
 icmp.c | 30 +++++++++++++++++++-----------
 icmp.h |  2 +-
 iov.c  | 23 -----------------------
 iov.h  |  2 --
 tap.c  |  7 ++-----
 5 files changed, 22 insertions(+), 42 deletions(-)

diff --git a/icmp.c b/icmp.c
index d27d860b4af4..44d431d53c96 100644
--- a/icmp.c
+++ b/icmp.c
@@ -44,6 +44,7 @@
 
 #define ICMP_ECHO_TIMEOUT	60 /* s, timeout for ICMP socket activity */
 #define ICMP_NUM_IDS		(1U << 16)
+#define MAX_IOV_ICMP		16
 
 /**
  * ping_at_sidx() - Get ping specific flow at given sidx
@@ -229,36 +230,33 @@ cancel:
  * @af:		Address family, AF_INET or AF_INET6
  * @saddr:	Source address
  * @daddr:	Destination address
- * @p:		Packet pool, single packet with ICMP/ICMPv6 header
+ * @data:	Single packet with ICMP/ICMPv6 header
  * @now:	Current timestamp
  *
  * Return: count of consumed packets (always 1, even if malformed)
  */
 int icmp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af,
 		     const void *saddr, const void *daddr,
-		     const struct pool *p, const struct timespec *now)
+		     struct iov_tail *data, const struct timespec *now)
 {
+	struct iovec iov[MAX_IOV_ICMP];
 	struct icmp_ping_flow *pingf;
 	const struct flowside *tgt;
 	union sockaddr_inany sa;
-	struct iov_tail data;
 	struct msghdr msh;
 	uint16_t id, seq;
 	union flow *flow;
 	uint8_t proto;
-	socklen_t sl;
+	int cnt;
 
 	(void)saddr;
 	ASSERT(pif == PIF_TAP);
 
-	if (!packet_data(p, 0, &data))
-		return -1;
-
 	if (af == AF_INET) {
 		const struct icmphdr *ih;
 		struct icmphdr ihc;
 
-		ih = IOV_PEEK_HEADER(&data, ihc);
+		ih = IOV_PEEK_HEADER(data, ihc);
 		if (!ih)
 			return 1;
 
@@ -272,7 +270,7 @@ int icmp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af,
 		const struct icmp6hdr *ih;
 		struct icmp6hdr ihc;
 
-		ih = IOV_PEEK_HEADER(&data, ihc);
+		ih = IOV_PEEK_HEADER(data, ihc);
 		if (!ih)
 			return 1;
 
@@ -286,6 +284,10 @@ int icmp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af,
 		ASSERT(0);
 	}
 
+	cnt = iov_tail_slice(&iov[0], MAX_IOV_ICMP, data, NULL);
+	if (cnt < 0)
+		return 1;
+
 	flow = flow_at_sidx(flow_lookup_af(c, proto, PIF_TAP,
 					   af, saddr, daddr, id, id));
 
@@ -300,8 +302,14 @@ int icmp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af,
 	pingf->ts = now->tv_sec;
 
 
-	pif_sockaddr(c, &sa, &sl, PIF_HOST, &tgt->eaddr, 0);
-	iov_tail_msghdr(&msh, &data, &sa, sl);
+	pif_sockaddr(c, &sa, &msh.msg_namelen, PIF_HOST, &tgt->eaddr, 0);
+	msh.msg_name = &sa;
+	msh.msg_iov = iov;
+	msh.msg_iovlen = cnt;
+	msh.msg_control = NULL;
+	msh.msg_controllen = 0;
+	msh.msg_flags = 0;
+
 	if (sendmsg(pingf->sock, &msh, MSG_NOSIGNAL) < 0) {
 		flow_dbg_perror(pingf, "failed to relay request to socket");
 	} else {
diff --git a/icmp.h b/icmp.h
index 5ce22b5eca1f..d1cecb20e29d 100644
--- a/icmp.h
+++ b/icmp.h
@@ -14,7 +14,7 @@ struct icmp_ping_flow;
 void icmp_sock_handler(const struct ctx *c, union epoll_ref ref);
 int icmp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af,
 		     const void *saddr, const void *daddr,
-		     const struct pool *p, const struct timespec *now);
+		     struct iov_tail *data, const struct timespec *now);
 void icmp_init(void);
 
 /**
diff --git a/iov.c b/iov.c
index f25ece225a4a..303351850e50 100644
--- a/iov.c
+++ b/iov.c
@@ -209,29 +209,6 @@ int iov_slice(struct iovec *dst_iov, size_t dst_iov_cnt,
 	return j;
 }
 
-/**
- * iov_tail_msghdr - Initialize a msghdr from an IOV tail structure
- * @msh:		msghdr to initialize
- * @tail:		iov_tail to use to set msg_iov and msg_iovlen
- * @msg_name:		Pointer to set to msg_name
- * @msg_namelen:	Size of @msg_name
- */
-void iov_tail_msghdr(struct msghdr *msh, struct iov_tail *tail,
-		     void *msg_name, socklen_t msg_namelen)
-{
-	iov_tail_prune(tail);
-
-	ASSERT(tail->off == 0);
-
-	msh->msg_name = msg_name;
-	msh->msg_namelen = msg_namelen;
-	msh->msg_iov = (struct iovec *)tail->iov;
-	msh->msg_iovlen = tail->cnt;
-	msh->msg_control = NULL;
-	msh->msg_controllen = 0;
-	msh->msg_flags = 0;
-}
-
 /**
  * iov_tail_prune() - Remove any unneeded buffers from an IOV tail
  * @tail:	IO vector tail (modified)
diff --git a/iov.h b/iov.h
index 8b73f99b063e..8e8c7efe6639 100644
--- a/iov.h
+++ b/iov.h
@@ -83,8 +83,6 @@ struct iov_tail {
 #define IOV_TAIL_FROM_BUF(buf_, len_, off_) \
 	IOV_TAIL((&(const struct iovec){ .iov_base = (buf_), .iov_len = (len_) }), 1, (off_))
 
-void iov_tail_msghdr(struct msghdr *msh, struct iov_tail *tail,
-		     void *msg_name, socklen_t msg_namelen);
 bool iov_tail_prune(struct iov_tail *tail);
 size_t iov_tail_size(struct iov_tail *tail);
 bool iov_tail_drop(struct iov_tail *tail, size_t len);
diff --git a/tap.c b/tap.c
index 5ab49935d318..d70e387fa7cc 100644
--- a/tap.c
+++ b/tap.c
@@ -762,17 +762,14 @@ resume:
 			continue;
 
 		if (iph->protocol == IPPROTO_ICMP) {
-			PACKET_POOL_P(pkt, 1, in->buf, in->buf_size);
-
 			if (c->no_icmp)
 				continue;
 
 			tap_packet_debug(iph, NULL, NULL, 0, NULL, 1);
 
-			packet_add(pkt, &data);
 			icmp_tap_handler(c, PIF_TAP, AF_INET,
 					 &iph->saddr, &iph->daddr,
-					 pkt, now);
+					 &data, now);
 			continue;
 		}
 
@@ -962,7 +959,7 @@ resume:
 			tap_packet_debug(NULL, ip6h, NULL, proto, NULL, 1);
 
 			icmp_tap_handler(c, PIF_TAP, AF_INET6,
-					 saddr, daddr, pkt, now);
+					 saddr, daddr, &data, now);
 			continue;
 		}
 
-- 
@@ -762,17 +762,14 @@ resume:
 			continue;
 
 		if (iph->protocol == IPPROTO_ICMP) {
-			PACKET_POOL_P(pkt, 1, in->buf, in->buf_size);
-
 			if (c->no_icmp)
 				continue;
 
 			tap_packet_debug(iph, NULL, NULL, 0, NULL, 1);
 
-			packet_add(pkt, &data);
 			icmp_tap_handler(c, PIF_TAP, AF_INET,
 					 &iph->saddr, &iph->daddr,
-					 pkt, now);
+					 &data, now);
 			continue;
 		}
 
@@ -962,7 +959,7 @@ resume:
 			tap_packet_debug(NULL, ip6h, NULL, proto, NULL, 1);
 
 			icmp_tap_handler(c, PIF_TAP, AF_INET6,
-					 saddr, daddr, pkt, now);
+					 saddr, daddr, &data, now);
 			continue;
 		}
 
-- 
2.49.0