[PATCH 18/18] tap: Convert to iov_tail

[Laurent Vivier <lvivier@redhat.com>]

Use packet_base() and extract headers using IOV_REMOVE_HEADER()
and IOV_PEEK_HEADER() rather than packet_get().

Remove packet_get() as it is not used anymore.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
 packet.c | 53 -----------------------------------------------------
 packet.h | 10 ----------
 tap.c    | 23 ++++++++++++++---------
 3 files changed, 14 insertions(+), 72 deletions(-)

diff --git a/packet.c b/packet.c
index 8066ac12502b..e917b0daad2a 100644
--- a/packet.c
+++ b/packet.c
@@ -103,59 +103,6 @@ void packet_add_do(struct pool *p, struct iov_tail *data,
 	p->count++;
 }
 
-/**
- * packet_get_do() - Get data range from packet descriptor from given pool
- * @p:		Packet pool
- * @idx:	Index of packet descriptor in pool
- * @offset:	Offset of data range in packet descriptor
- * @len:	Length of desired data range
- * @left:	Length of available data after range, set on return, can be NULL
- * @func:	For tracing: name of calling function, NULL means no trace()
- * @line:	For tracing: caller line of function call
- *
- * Return: pointer to start of data range, NULL on invalid range or descriptor
- */
-void *packet_get_do(const struct pool *p, size_t idx, size_t offset,
-		    size_t len, size_t *left, const char *func, int line)
-{
-	char *ptr;
-
-	if (idx >= p->size || idx >= p->count) {
-		if (func) {
-			trace("packet %zu from pool size: %zu, count: %zu, "
-			      "%s:%i", idx, p->size, p->count, func, line);
-		}
-		return NULL;
-	}
-
-	if (len > PACKET_MAX_LEN) {
-		if (func) {
-			trace("packet data length %zu, %s:%i",
-			      len, func, line);
-		}
-		return NULL;
-	}
-
-	if (len + offset > p->pkt[idx].iov_len) {
-		if (func) {
-			trace("data length %zu, offset %zu from length %zu, "
-			      "%s:%i", len, offset, p->pkt[idx].iov_len,
-			      func, line);
-		}
-		return NULL;
-	}
-
-	ptr = (char *)p->pkt[idx].iov_base + offset;
-
-	if (packet_check_range(p, ptr, len, func, line))
-		return NULL;
-
-	if (left)
-		*left = p->pkt[idx].iov_len - offset - len;
-
-	return ptr;
-}
-
 /**
  * packet_base_do() - Get data range from packet descriptor from given pool
  * @p:		Packet pool
diff --git a/packet.h b/packet.h
index 35058e747a43..787535a228a5 100644
--- a/packet.h
+++ b/packet.h
@@ -32,9 +32,6 @@ struct pool {
 int vu_packet_check_range(void *buf, const char *ptr, size_t len);
 void packet_add_do(struct pool *p, struct iov_tail *data,
 		   const char *func, int line);
-void *packet_get_do(const struct pool *p, const size_t idx,
-		    size_t offset, size_t len, size_t *left,
-		    const char *func, int line);
 bool packet_base_do(const struct pool *p, const size_t idx,
 		    struct iov_tail *data,
 		    const char *func, int line);
@@ -43,13 +40,6 @@ void pool_flush(struct pool *p);
 #define packet_add(p, data)					\
 	packet_add_do(p, data, __func__, __LINE__)
 
-#define packet_get(p, idx, offset, len, left)				\
-	packet_get_do(p, idx, offset, len, left, __func__, __LINE__)
-
-
-#define packet_get_try(p, idx, offset, len, left)			\
-	packet_get_do(p, idx, offset, len, left, NULL, 0)
-
 #define packet_base(p, idx, data)					\
 	packet_base_do(p, idx, data, __func__, __LINE__)
 
diff --git a/tap.c b/tap.c
index 280a04981954..d6a1da8481a2 100644
--- a/tap.c
+++ b/tap.c
@@ -870,17 +870,24 @@ resume:
 		const struct udphdr *uh;
 		struct iov_tail data;
 		struct ipv6hdr *ip6h;
+		struct ipv6hdr ip6hc;
+		struct ethhdr ehc;
+		struct udphdr uhc;
 		uint8_t proto;
-		char *l4h;
 
-		eh =   packet_get(in, i, 0,		sizeof(*eh), NULL);
+		if (!packet_base(in, i, &data))
+			return -1;
+
+		eh = IOV_REMOVE_HEADER(&data, ehc);
 		if (!eh)
 			continue;
 
-		ip6h = packet_get(in, i, sizeof(*eh),	sizeof(*ip6h), &check);
+		ip6h = IOV_PEEK_HEADER(&data, ip6hc);
 		if (!ip6h)
 			continue;
 
+		check = iov_tail_size(&data) - sizeof(*ip6h);
+
 		saddr = &ip6h->saddr;
 		daddr = &ip6h->daddr;
 
@@ -888,10 +895,8 @@ resume:
 		if (plen != check)
 			continue;
 
-		data = IOV_TAIL_FROM_BUF(ip6h, sizeof(*ip6h) + check, 0);
 		if (!ipv6_l4hdr(&data, &proto, &l4len))
 			continue;
-		l4h = (char *)data.iov[0].iov_base + data.off;
 
 		if (IN6_IS_ADDR_LOOPBACK(saddr) || IN6_IS_ADDR_LOOPBACK(daddr)) {
 			char sstr[INET6_ADDRSTRLEN], dstr[INET6_ADDRSTRLEN];
@@ -916,6 +921,8 @@ resume:
 		}
 
 		if (proto == IPPROTO_ICMPV6) {
+			const struct icmp6hdr *l4h;
+			struct icmp6hdr l4hc;
 			PACKET_POOL_P(pkt, 1, in->buf, in->buf_size);
 
 			if (c->no_icmp)
@@ -924,9 +931,9 @@ resume:
 			if (l4len < sizeof(struct icmp6hdr))
 				continue;
 
-			data = IOV_TAIL_FROM_BUF(l4h, l4len, 0);
 			packet_add(pkt, &data);
 
+			l4h = IOV_PEEK_HEADER(&data, l4hc);
 			if (ndp(c, (struct icmp6hdr *)l4h, saddr, pkt))
 				continue;
 
@@ -939,12 +946,11 @@ resume:
 
 		if (l4len < sizeof(*uh))
 			continue;
-		uh = (struct udphdr *)l4h;
+		uh = IOV_PEEK_HEADER(&data, uhc);
 
 		if (proto == IPPROTO_UDP) {
 			PACKET_POOL_P(pkt, 1, in->buf, in->buf_size);
 
-			data = IOV_TAIL_FROM_BUF(l4h, l4len, 0);
 			packet_add(pkt, &data);
 
 			if (dhcpv6(c, pkt, saddr, daddr))
@@ -999,7 +1005,6 @@ resume:
 #undef L4_SET
 
 append:
-		data = IOV_TAIL_FROM_BUF(l4h, l4len, 0);
 		packet_add((struct pool *)&seq->p, &data);
 	}
 
-- 
@@ -870,17 +870,24 @@ resume:
 		const struct udphdr *uh;
 		struct iov_tail data;
 		struct ipv6hdr *ip6h;
+		struct ipv6hdr ip6hc;
+		struct ethhdr ehc;
+		struct udphdr uhc;
 		uint8_t proto;
-		char *l4h;
 
-		eh =   packet_get(in, i, 0,		sizeof(*eh), NULL);
+		if (!packet_base(in, i, &data))
+			return -1;
+
+		eh = IOV_REMOVE_HEADER(&data, ehc);
 		if (!eh)
 			continue;
 
-		ip6h = packet_get(in, i, sizeof(*eh),	sizeof(*ip6h), &check);
+		ip6h = IOV_PEEK_HEADER(&data, ip6hc);
 		if (!ip6h)
 			continue;
 
+		check = iov_tail_size(&data) - sizeof(*ip6h);
+
 		saddr = &ip6h->saddr;
 		daddr = &ip6h->daddr;
 
@@ -888,10 +895,8 @@ resume:
 		if (plen != check)
 			continue;
 
-		data = IOV_TAIL_FROM_BUF(ip6h, sizeof(*ip6h) + check, 0);
 		if (!ipv6_l4hdr(&data, &proto, &l4len))
 			continue;
-		l4h = (char *)data.iov[0].iov_base + data.off;
 
 		if (IN6_IS_ADDR_LOOPBACK(saddr) || IN6_IS_ADDR_LOOPBACK(daddr)) {
 			char sstr[INET6_ADDRSTRLEN], dstr[INET6_ADDRSTRLEN];
@@ -916,6 +921,8 @@ resume:
 		}
 
 		if (proto == IPPROTO_ICMPV6) {
+			const struct icmp6hdr *l4h;
+			struct icmp6hdr l4hc;
 			PACKET_POOL_P(pkt, 1, in->buf, in->buf_size);
 
 			if (c->no_icmp)
@@ -924,9 +931,9 @@ resume:
 			if (l4len < sizeof(struct icmp6hdr))
 				continue;
 
-			data = IOV_TAIL_FROM_BUF(l4h, l4len, 0);
 			packet_add(pkt, &data);
 
+			l4h = IOV_PEEK_HEADER(&data, l4hc);
 			if (ndp(c, (struct icmp6hdr *)l4h, saddr, pkt))
 				continue;
 
@@ -939,12 +946,11 @@ resume:
 
 		if (l4len < sizeof(*uh))
 			continue;
-		uh = (struct udphdr *)l4h;
+		uh = IOV_PEEK_HEADER(&data, uhc);
 
 		if (proto == IPPROTO_UDP) {
 			PACKET_POOL_P(pkt, 1, in->buf, in->buf_size);
 
-			data = IOV_TAIL_FROM_BUF(l4h, l4len, 0);
 			packet_add(pkt, &data);
 
 			if (dhcpv6(c, pkt, saddr, daddr))
@@ -999,7 +1005,6 @@ resume:
 #undef L4_SET
 
 append:
-		data = IOV_TAIL_FROM_BUF(l4h, l4len, 0);
 		packet_add((struct pool *)&seq->p, &data);
 	}
 
-- 
2.49.0