From: Laurent Vivier <lvivier(a)redhat.com>
Replace the macro SET_TCP_HEADER_COMMON_V4_V6() by a new function
tcp_fill_header().
Move IPv4 and IPv6 code from tcp_l2_buf_fill_headers() to
tcp_fill_ipv4_header() and tcp_fill_ipv6_header()
Signed-off-by: Laurent Vivier <lvivier(a)redhat.com>
Message-ID: <20240303135114.1023026-10-lvivier(a)redhat.com>
---
tcp.c | 156 +++++++++++++++++++++++++++++++++++++++-------------------
1 file changed, 106 insertions(+), 50 deletions(-)
diff --git a/tcp.c b/tcp.c
index db42d535..d5eedf4d 100644
--- a/tcp.c
+++ b/tcp.c
@@ -1327,6 +1327,108 @@ void tcp_defer_handler(struct ctx *c)
tcp_l2_data_buf_flush(c);
}
+/**
+ * tcp_fill_header() - Fill the TCP header fields for a given TCP segment.
+ *
+ * @th: Pointer to the TCP header structure
+ * @conn: Pointer to the TCP connection structure
+ * @seq: Sequence number
+ */
+static void tcp_fill_header(struct tcphdr *th,
+ const struct tcp_tap_conn *conn, uint32_t seq)
+{
+ th->source = htons(conn->fport);
+ th->dest = htons(conn->eport);
+ th->seq = htonl(seq);
+ th->ack_seq = htonl(conn->seq_ack_to_tap);
+ if (conn->events & ESTABLISHED) {
+ th->window = htons(conn->wnd_to_tap);
+ } else {
+ unsigned wnd = conn->wnd_to_tap << conn->ws_to_tap;
+
+ th->window = htons(MIN(wnd, USHRT_MAX));
+ }
+}
+
+/**
+ * tcp_fill_headers4() - Fill 802.3, IPv4, TCP headers in pre-cooked buffers
+ * @c: Execution context
+ * @conn: Connection pointer
+ * @iph: Pointer to IPv4 header
+ * @th: Pointer to TCP header
+ * @plen: Payload length (including TCP header options)
+ * @check: Checksum, if already known
+ * @seq: Sequence number for this segment
+ *
+ * Return: The total length of the IPv4 packet, host order
+ */
+static size_t tcp_fill_headers4(const struct ctx *c,
+ const struct tcp_tap_conn *conn,
+ struct iphdr *iph, struct tcphdr *th,
+ size_t plen, const uint16_t *check,
+ uint32_t seq)
+{
+ size_t ip_len = plen + sizeof(struct iphdr) + sizeof(struct tcphdr);
+ const struct in_addr *a4 = inany_v4(&conn->faddr);
+
+ ASSERT(a4);
+
+ iph->tot_len = htons(ip_len);
+ iph->saddr = a4->s_addr;
+ iph->daddr = c->ip4.addr_seen.s_addr;
+
+ iph->check = check ? *check :
+ csum_ip4_header(iph->tot_len, IPPROTO_TCP,
+ *a4, c->ip4.addr_seen);
+
+ tcp_fill_header(th, conn, seq);
+
+ tcp_update_check_tcp4(iph, th);
+
+ return ip_len;
+}
+
+/**
+ * tcp_fill_headers6() - Fill 802.3, IPv6, TCP headers in pre-cooked buffers
+ * @c: Execution context
+ * @conn: Connection pointer
+ * @ip6h: Pointer to IPv6 header
+ * @th: Pointer to TCP header
+ * @plen: Payload length (including TCP header options)
+ * @check: Checksum, if already known
+ * @seq: Sequence number for this segment
+ *
+ * Return: The total length of the IPv6 packet, host order
+ */
+static size_t tcp_fill_headers6(const struct ctx *c,
+ const struct tcp_tap_conn *conn,
+ struct ipv6hdr *ip6h, struct tcphdr *th,
+ size_t plen, uint32_t seq)
+{
+ size_t ip_len = plen + sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
+
+ ip6h->payload_len = htons(plen + sizeof(struct tcphdr));
+ ip6h->saddr = conn->faddr.a6;
+ if (IN6_IS_ADDR_LINKLOCAL(&ip6h->saddr))
+ ip6h->daddr = c->ip6.addr_ll_seen;
+ else
+ ip6h->daddr = c->ip6.addr_seen;
+
+ ip6h->hop_limit = 255;
+ ip6h->version = 6;
+ ip6h->nexthdr = IPPROTO_TCP;
+
+ ip6h->flow_lbl[0] = (conn->sock >> 16) & 0xf;
+ ip6h->flow_lbl[1] = (conn->sock >> 8) & 0xff;
+ ip6h->flow_lbl[2] = (conn->sock >> 0) & 0xff;
+
+ tcp_fill_header(th, conn, seq);
+
+ tcp_update_check_tcp6(ip6h, th);
+
+ return ip_len;
+}
+
/**
* tcp_l2_buf_fill_headers() - Fill 802.3, IP, TCP headers in pre-cooked buffers
* @c: Execution context
@@ -1346,67 +1448,21 @@ static size_t tcp_l2_buf_fill_headers(const struct ctx *c,
const struct in_addr *a4 = inany_v4(&conn->faddr);
size_t ip_len, tlen;
-#define SET_TCP_HEADER_COMMON_V4_V6(b, conn, seq) \
-do { \
- b->th.source = htons(conn->fport); \
- b->th.dest = htons(conn->eport); \
- b->th.seq = htonl(seq); \
- b->th.ack_seq = htonl(conn->seq_ack_to_tap); \
- if (conn->events & ESTABLISHED) { \
- b->th.window = htons(conn->wnd_to_tap); \
- } else { \
- unsigned wnd = conn->wnd_to_tap << conn->ws_to_tap; \
- \
- b->th.window = htons(MIN(wnd, USHRT_MAX)); \
- } \
-} while (0)
-
if (a4) {
struct tcp4_l2_buf_t *b = (struct tcp4_l2_buf_t *)p;
- ip_len = plen + sizeof(struct iphdr) + sizeof(struct tcphdr);
- b->iph.tot_len = htons(ip_len);
- b->iph.saddr = a4->s_addr;
- b->iph.daddr = c->ip4.addr_seen.s_addr;
-
- b->iph.check = check ? *check :
- csum_ip4_header(b->iph.tot_len, IPPROTO_TCP,
- *a4, c->ip4.addr_seen);
-
- SET_TCP_HEADER_COMMON_V4_V6(b, conn, seq);
-
- tcp_update_check_tcp4(&b->iph, &b->th);
+ ip_len = tcp_fill_headers4(c, conn, &b->iph, &b->th, plen,
+ check, seq);
tlen = tap_iov_len(c, &b->taph, ip_len);
} else {
struct tcp6_l2_buf_t *b = (struct tcp6_l2_buf_t *)p;
- ip_len = plen + sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
-
- b->ip6h.payload_len = htons(plen + sizeof(struct tcphdr));
- b->ip6h.saddr = conn->faddr.a6;
- if (IN6_IS_ADDR_LINKLOCAL(&b->ip6h.saddr))
- b->ip6h.daddr = c->ip6.addr_ll_seen;
- else
- b->ip6h.daddr = c->ip6.addr_seen;
-
- memset(b->ip6h.flow_lbl, 0, 3);
-
- SET_TCP_HEADER_COMMON_V4_V6(b, conn, seq);
-
- tcp_update_check_tcp6(&b->ip6h, &b->th);
-
- b->ip6h.hop_limit = 255;
- b->ip6h.version = 6;
- b->ip6h.nexthdr = IPPROTO_TCP;
-
- b->ip6h.flow_lbl[0] = (conn->sock >> 16) & 0xf;
- b->ip6h.flow_lbl[1] = (conn->sock >> 8) & 0xff;
- b->ip6h.flow_lbl[2] = (conn->sock >> 0) & 0xff;
+ ip_len = tcp_fill_headers6(c, conn, &b->ip6h, &b->th, plen,
+ seq);
tlen = tap_iov_len(c, &b->taph, ip_len);
}
-#undef SET_TCP_HEADER_COMMON_V4_V6
return tlen;
}
--
2.44.0