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Diffstat (limited to 'tcp.c')
-rw-r--r--tcp.c144
1 files changed, 72 insertions, 72 deletions
diff --git a/tcp.c b/tcp.c
index 5c84881..4a95197 100644
--- a/tcp.c
+++ b/tcp.c
@@ -1359,40 +1359,6 @@ static size_t tcp_fill_headers6(const struct ctx *c,
}
/**
- * tcp_l2_buf_fill_headers() - Fill 802.3, IP, TCP headers in pre-cooked buffers
- * @c: Execution context
- * @conn: Connection pointer
- * @iov: Pointer to an array of iovec of TCP pre-cooked buffer
- * @plen: Payload length (including TCP header options)
- * @check: Checksum, if already known
- * @seq: Sequence number for this segment
- *
- * Return: frame length including L2 headers, host order
- */
-static size_t tcp_l2_buf_fill_headers(const struct ctx *c,
- const struct tcp_tap_conn *conn,
- struct iovec *iov, size_t plen,
- const uint16_t *check, uint32_t seq)
-{
- const struct in_addr *a4 = inany_v4(&conn->faddr);
- size_t ip_len, tlen;
-
- if (a4) {
- ip_len = tcp_fill_headers4(c, conn, iov[TCP_IOV_IP].iov_base,
- iov[TCP_IOV_PAYLOAD].iov_base, plen,
- check, seq);
- tlen = ip_len - sizeof(struct iphdr);
- } else {
- ip_len = tcp_fill_headers6(c, conn, iov[TCP_IOV_IP].iov_base,
- iov[TCP_IOV_PAYLOAD].iov_base, plen,
- seq);
- tlen = ip_len - sizeof(struct ipv6hdr);
- }
-
- return tlen;
-}
-
-/**
* tcp_update_seqack_wnd() - Update ACK sequence and window to guest/tap
* @c: Execution context
* @conn: Connection pointer
@@ -1509,26 +1475,27 @@ static void tcp_update_seqack_from_tap(const struct ctx *c,
}
/**
- * tcp_send_flag() - Send segment with flags to tap (no payload)
+ * tcp_fill_flag_header() - Prepare header for flags-only segment (no payload)
* @c: Execution context
* @conn: Connection pointer
* @flags: TCP flags: if not set, send segment only if ACK is due
+ * @th: TCP header to update
+ * @opts: buffer to store TCP option
+ * @optlen: size of the TCP option buffer
*
- * Return: negative error code on connection reset, 0 otherwise
+ * Return: < 0 error code on connection reset,
+ * 0 if there is no flag to send
+ * 1 otherwise
*/
-static int tcp_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags)
+static int tcp_fill_flag_header(struct ctx *c, struct tcp_tap_conn *conn,
+ int flags, struct tcphdr *th, char *opts,
+ size_t *optlen)
{
uint32_t prev_ack_to_tap = conn->seq_ack_to_tap;
uint32_t prev_wnd_to_tap = conn->wnd_to_tap;
- struct tcp_l2_flags_t *payload;
struct tcp_info tinfo = { 0 };
socklen_t sl = sizeof(tinfo);
int s = conn->sock;
- size_t optlen = 0;
- struct iovec *iov;
- struct iovec *dup_iov;
- struct tcphdr *th;
- char *data;
if (SEQ_GE(conn->seq_ack_to_tap, conn->seq_from_tap) &&
!flags && conn->wnd_to_tap)
@@ -1550,25 +1517,14 @@ static int tcp_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags)
if (!tcp_update_seqack_wnd(c, conn, flags, &tinfo) && !flags)
return 0;
- if (CONN_V4(conn)) {
- iov = tcp4_l2_flags_iov[tcp4_l2_flags_buf_used++];
- dup_iov = tcp4_l2_flags_iov[tcp4_l2_flags_buf_used];
- } else {
- iov = tcp6_l2_flags_iov[tcp6_l2_flags_buf_used++];
- dup_iov = tcp6_l2_flags_iov[tcp6_l2_flags_buf_used];
- }
- payload = iov[TCP_IOV_PAYLOAD].iov_base;
- th = &payload->th;
- data = payload->opts;
-
if (flags & SYN) {
int mss;
/* Options: MSS, NOP and window scale (8 bytes) */
- optlen = OPT_MSS_LEN + 1 + OPT_WS_LEN;
+ *optlen = OPT_MSS_LEN + 1 + OPT_WS_LEN;
- *data++ = OPT_MSS;
- *data++ = OPT_MSS_LEN;
+ *opts++ = OPT_MSS;
+ *opts++ = OPT_MSS_LEN;
if (c->mtu == -1) {
mss = tinfo.tcpi_snd_mss;
@@ -1581,16 +1537,16 @@ static int tcp_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags)
else if (mss > PAGE_SIZE)
mss = ROUND_DOWN(mss, PAGE_SIZE);
}
- *(uint16_t *)data = htons(MIN(USHRT_MAX, mss));
+ *(uint16_t *)opts = htons(MIN(USHRT_MAX, mss));
- data += OPT_MSS_LEN - 2;
+ opts += OPT_MSS_LEN - 2;
conn->ws_to_tap = MIN(MAX_WS, tinfo.tcpi_snd_wscale);
- *data++ = OPT_NOP;
- *data++ = OPT_WS;
- *data++ = OPT_WS_LEN;
- *data++ = conn->ws_to_tap;
+ *opts++ = OPT_NOP;
+ *opts++ = OPT_WS;
+ *opts++ = OPT_WS_LEN;
+ *opts++ = conn->ws_to_tap;
th->ack = !!(flags & ACK);
} else {
@@ -1599,16 +1555,12 @@ static int tcp_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags)
!prev_wnd_to_tap;
}
- th->doff = (sizeof(*th) + optlen) / 4;
+ th->doff = (sizeof(*th) + *optlen) / 4;
th->rst = !!(flags & RST);
th->syn = !!(flags & SYN);
th->fin = !!(flags & FIN);
- iov[TCP_IOV_PAYLOAD].iov_len = tcp_l2_buf_fill_headers(c, conn, iov,
- optlen, NULL,
- conn->seq_to_tap);
-
if (th->ack) {
if (SEQ_GE(conn->seq_ack_to_tap, conn->seq_from_tap))
conn_flag(c, conn, ~ACK_TO_TAP_DUE);
@@ -1623,6 +1575,48 @@ static int tcp_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags)
if (th->fin || th->syn)
conn->seq_to_tap++;
+ return 1;
+}
+
+static int tcp_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags)
+{
+ struct tcp_l2_flags_t *payload;
+ struct iovec *dup_iov;
+ struct iovec *iov;
+ struct tcphdr *th;
+ size_t optlen = 0;
+ size_t ip_len;
+ char *data;
+ int ret;
+
+ if (CONN_V4(conn)) {
+ iov = tcp4_l2_flags_iov[tcp4_l2_flags_buf_used++];
+ dup_iov = tcp4_l2_flags_iov[tcp4_l2_flags_buf_used];
+ } else {
+ iov = tcp6_l2_flags_iov[tcp6_l2_flags_buf_used++];
+ dup_iov = tcp6_l2_flags_iov[tcp6_l2_flags_buf_used];
+ }
+ payload = iov[TCP_IOV_PAYLOAD].iov_base;
+ th = &payload->th;
+ data = payload->opts;
+
+ ret = tcp_fill_flag_header(c, conn, flags, th, data, &optlen);
+ if (ret <= 0)
+ return ret;
+
+ if (CONN_V4(conn)) {
+ struct iphdr *iph = iov[TCP_IOV_IP].iov_base;
+
+ ip_len = tcp_fill_headers4(c, conn, iph, th, optlen, NULL,
+ conn->seq_to_tap);
+ } else {
+ struct ipv6hdr *ip6h = iov[TCP_IOV_IP].iov_base;
+
+ ip_len = tcp_fill_headers6(c, conn, ip6h, th, optlen,
+ conn->seq_to_tap);
+ }
+ iov[TCP_IOV_PAYLOAD].iov_len = ip_len;
+
if (flags & DUP_ACK) {
int i;
for (i = 0; i < TCP_IOV_NUM; i++) {
@@ -2103,8 +2097,11 @@ static void tcp_data_to_tap(const struct ctx *c, struct tcp_tap_conn *conn,
tcp4_l2_buf_seq_update[tcp4_l2_buf_used].len = plen;
iov = tcp4_l2_iov[tcp4_l2_buf_used++];
- iov[TCP_IOV_PAYLOAD].iov_len = tcp_l2_buf_fill_headers(c, conn,
- iov, plen, check, seq);
+ iov[TCP_IOV_PAYLOAD].iov_len = tcp_fill_headers4(c, conn,
+ iov[TCP_IOV_IP].iov_base,
+ iov[TCP_IOV_PAYLOAD].iov_base,
+ plen, check, seq);
+
if (tcp4_l2_buf_used > TCP_FRAMES_MEM - 1)
tcp_l2_data_buf_flush(c);
} else if (CONN_V6(conn)) {
@@ -2112,8 +2109,11 @@ static void tcp_data_to_tap(const struct ctx *c, struct tcp_tap_conn *conn,
tcp6_l2_buf_seq_update[tcp6_l2_buf_used].len = plen;
iov = tcp6_l2_iov[tcp6_l2_buf_used++];
- iov[TCP_IOV_PAYLOAD].iov_len = tcp_l2_buf_fill_headers(c, conn,
- iov, plen, NULL, seq);
+ iov[TCP_IOV_PAYLOAD].iov_len = tcp_fill_headers6(c, conn,
+ iov[TCP_IOV_IP].iov_base,
+ iov[TCP_IOV_PAYLOAD].iov_base,
+ plen, seq);
+
if (tcp6_l2_buf_used > TCP_FRAMES_MEM - 1)
tcp_l2_data_buf_flush(c);
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-11 00:40:49 +0000