On 12/06/2024 17:52, Stefano Brivio wrote:
On Wed, 12 Jun 2024 17:47:29 +0200
Laurent Vivier <lvivier(a)redhat.com> wrote:
Consolidate pool_tap4() and pool_tap6() into
tap_flush_pools(),
and tap4_handler() and tap6_handler() into tap_handler().
Create a generic tap_add_packet() to consolidate packet
addition logic and reduce code duplication.
The purpose is to ease the export of these functions to use
them with the vhost-user backend.
Signed-off-by: Laurent Vivier <lvivier(a)redhat.com>
---
Notes:
v6:
- rename tap_handler_all() to tap_handler()
- rename packet_add_all_do() to tap_add_packet
and remove func and line.
Oops, they're still in the comment to the function. I can drop that on
merge.
yes, please, and also the comment of tap_flush_pools()
Thanks,
Laurent >
-
rename pool_flush_all() to tap_flush_pools()
v5:
- update commit message and function comments
tap.c | 112 +++++++++++++++++++++++++++++++++-------------------------
tap.h | 3 ++
2 files changed, 66 insertions(+), 49 deletions(-)
diff --git a/tap.c b/tap.c
index 26084b486519..ec3a0d68ea2f 100644
--- a/tap.c
+++ b/tap.c
@@ -921,6 +921,60 @@ append:
return in->count;
}
+/**
+ * pool_flush() - Flush both IPv4 and IPv6 packet pools
+ */
+void tap_flush_pools(void)
+{
+ pool_flush(pool_tap4);
+ pool_flush(pool_tap6);
+}
+
+/**
+ * tap_handler() - IPv4/IPv6 and ARP packet handler for tap file descriptor
+ * @c: Execution context
+ * @now: Current timestamp
+ */
+void tap_handler(struct ctx *c, const struct timespec *now)
+{
+ tap4_handler(c, pool_tap4, now);
+ tap6_handler(c, pool_tap6, now);
+}
+
+/**
+ * tap_add_packet() - Queue/capture packet, update notion of guest MAC address
+ * @c: Execution context
+ * @l2len: Total L2 packet length
+ * @p: Packet buffer
+ * @func: For tracing: name of calling function, NULL means no trace()
+ * @line: For tracing: caller line of function call
+ */
+void tap_add_packet(struct ctx *c, ssize_t l2len, char *p)
+{
+ const struct ethhdr *eh;
+
+ pcap(p, l2len);
+
+ eh = (struct ethhdr *)p;
+
+ if (memcmp(c->mac_guest, eh->h_source, ETH_ALEN)) {
+ memcpy(c->mac_guest, eh->h_source, ETH_ALEN);
+ proto_update_l2_buf(c->mac_guest, NULL);
+ }
+
+ switch (ntohs(eh->h_proto)) {
+ case ETH_P_ARP:
+ case ETH_P_IP:
+ packet_add(pool_tap4, l2len, p);
+ break;
+ case ETH_P_IPV6:
+ packet_add(pool_tap6, l2len, p);
+ break;
+ default:
+ break;
+ }
+}
+
/**
* tap_sock_reset() - Handle closing or failure of connect AF_UNIX socket
* @c: Execution context
@@ -947,7 +1001,6 @@ static void tap_sock_reset(struct ctx *c)
void tap_handler_passt(struct ctx *c, uint32_t events,
const struct timespec *now)
{
- const struct ethhdr *eh;
ssize_t n, rem;
char *p;
@@ -960,8 +1013,7 @@ redo:
p = pkt_buf;
rem = 0;
- pool_flush(pool_tap4);
- pool_flush(pool_tap6);
+ tap_flush_pools();
n = recv(c->fd_tap, p, TAP_BUF_FILL, MSG_DONTWAIT);
if (n < 0) {
@@ -988,38 +1040,18 @@ redo:
/* Complete the partial read above before discarding a malformed
* frame, otherwise the stream will be inconsistent.
*/
- if (l2len < (ssize_t)sizeof(*eh) ||
+ if (l2len < (ssize_t)sizeof(struct ethhdr) ||
l2len > (ssize_t)ETH_MAX_MTU)
goto next;
- pcap(p, l2len);
-
- eh = (struct ethhdr *)p;
-
- if (memcmp(c->mac_guest, eh->h_source, ETH_ALEN)) {
- memcpy(c->mac_guest, eh->h_source, ETH_ALEN);
- proto_update_l2_buf(c->mac_guest, NULL);
- }
-
- switch (ntohs(eh->h_proto)) {
- case ETH_P_ARP:
- case ETH_P_IP:
- packet_add(pool_tap4, l2len, p);
- break;
- case ETH_P_IPV6:
- packet_add(pool_tap6, l2len, p);
- break;
- default:
- break;
- }
+ tap_add_packet(c, l2len, p);
next:
p += l2len;
n -= l2len;
}
- tap4_handler(c, pool_tap4, now);
- tap6_handler(c, pool_tap6, now);
+ tap_handler(c, now);
/* We can't use EPOLLET otherwise. */
if (rem)
@@ -1044,35 +1076,18 @@ void tap_handler_pasta(struct ctx *c, uint32_t events,
redo:
n = 0;
- pool_flush(pool_tap4);
- pool_flush(pool_tap6);
+ tap_flush_pools();
restart:
while ((len = read(c->fd_tap, pkt_buf + n, TAP_BUF_BYTES - n)) > 0) {
- const struct ethhdr *eh = (struct ethhdr *)(pkt_buf + n);
- if (len < (ssize_t)sizeof(*eh) || len > (ssize_t)ETH_MAX_MTU) {
+ if (len < (ssize_t)sizeof(struct ethhdr) ||
+ len > (ssize_t)ETH_MAX_MTU) {
n += len;
continue;
}
- pcap(pkt_buf + n, len);
- if (memcmp(c->mac_guest, eh->h_source, ETH_ALEN)) {
- memcpy(c->mac_guest, eh->h_source, ETH_ALEN);
- proto_update_l2_buf(c->mac_guest, NULL);
- }
-
- switch (ntohs(eh->h_proto)) {
- case ETH_P_ARP:
- case ETH_P_IP:
- packet_add(pool_tap4, len, pkt_buf + n);
- break;
- case ETH_P_IPV6:
- packet_add(pool_tap6, len, pkt_buf + n);
- break;
- default:
- break;
- }
+ tap_add_packet(c, len, pkt_buf + n);
if ((n += len) == TAP_BUF_BYTES)
break;
@@ -1083,8 +1098,7 @@ restart:
ret = errno;
- tap4_handler(c, pool_tap4, now);
- tap6_handler(c, pool_tap6, now);
+ tap_handler(c, now);
if (len > 0 || ret == EAGAIN)
return;
diff --git a/tap.h b/tap.h
index 2285a87093f9..d496bd0e4b99 100644
--- a/tap.h
+++ b/tap.h
@@ -70,5 +70,8 @@ void tap_handler_passt(struct ctx *c, uint32_t events,
const struct timespec *now);
int tap_sock_unix_open(char *sock_path);
void tap_sock_init(struct ctx *c);
+void tap_flush_pools(void);
+void tap_handler(struct ctx *c, const struct timespec *now);
+void tap_add_packet(struct ctx *c, ssize_t l2len, char *p);
#endif /* TAP_H */