From: David Gibson <david@gibson.dropbear.id.au>
To: Stefano Brivio <sbrivio@redhat.com>, passt-dev@passt.top
Cc: David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCH 2/2] tcp: Use runtime tests for TCP_INFO fields
Date: Wed, 23 Oct 2024 11:42:53 +1100 [thread overview]
Message-ID: <20241023004253.1729124-3-david@gibson.dropbear.id.au> (raw)
In-Reply-To: <20241023004253.1729124-1-david@gibson.dropbear.id.au>
In order to use particular fields from the TCP_INFO getsockopt() we
need them to be in the version of the structure we have defined. We
test this in the Makefile, setting HAS_BYTES_ACKED and HAS_MIN_RTT
accordingly.
However, we also need the fields to be present in the runtime kernel
we're using, which we don't currently check for those fields. Add
logic similar to that for tcpi_snd_wnd to check for these fields too
instead of just using the compile time check.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
tcp.c | 65 +++++++++++++++++++++++++++++++++++------------------------
1 file changed, 39 insertions(+), 26 deletions(-)
diff --git a/tcp.c b/tcp.c
index 3cca5c6..b5ef1f1 100644
--- a/tcp.c
+++ b/tcp.c
@@ -380,6 +380,19 @@ socklen_t tcp_info_size;
#else
#define snd_wnd_cap (false)
#endif
+#ifdef HAS_BYTES_ACKED
+/* Does the kernel report bytes acked in TCP_INFO (kernel commit 0df48c26d84) */
+#define bytes_acked_cap tcp_info_cap(bytes_acked)
+#else
+#define bytes_acked_cap (false)
+#endif
+#ifdef HAS_MIN_RTT
+/* Does the kernel report minimum RTT TCP_INFO (kernel commit cd9b266095f4) */
+#define min_rtt_cap tcp_info_cap(min_rtt)
+#else
+#define min_rtt_cap (false)
+#endif
+
/* sendmsg() to socket */
static struct iovec tcp_iov [UIO_MAXIOV];
@@ -687,11 +700,10 @@ static int tcp_rtt_dst_low(const struct tcp_tap_conn *conn)
static void tcp_rtt_dst_check(const struct tcp_tap_conn *conn,
const struct tcp_info *tinfo)
{
-#ifdef HAS_MIN_RTT
const struct flowside *tapside = TAPFLOW(conn);
int i, hole = -1;
- if (!tinfo->tcpi_min_rtt ||
+ if (!min_rtt_cap ||
(int)tinfo->tcpi_min_rtt > LOW_RTT_THRESHOLD)
return;
@@ -712,10 +724,6 @@ static void tcp_rtt_dst_check(const struct tcp_tap_conn *conn,
if (hole == LOW_RTT_TABLE_SIZE)
hole = 0;
inany_from_af(low_rtt_dst + hole, AF_INET6, &in6addr_any);
-#else
- (void)conn;
- (void)tinfo;
-#endif /* HAS_MIN_RTT */
}
/**
@@ -1131,30 +1139,29 @@ int tcp_update_seqack_wnd(const struct ctx *c, struct tcp_tap_conn *conn,
uint32_t new_wnd_to_tap = prev_wnd_to_tap;
int s = conn->sock;
-#ifndef HAS_BYTES_ACKED
- (void)force_seq;
-
- conn->seq_ack_to_tap = conn->seq_from_tap;
- if (SEQ_LT(conn->seq_ack_to_tap, prev_ack_to_tap))
- conn->seq_ack_to_tap = prev_ack_to_tap;
-#else
- if ((unsigned)SNDBUF_GET(conn) < SNDBUF_SMALL || tcp_rtt_dst_low(conn)
- || CONN_IS_CLOSING(conn) || (conn->flags & LOCAL) || force_seq) {
+ if (!bytes_acked_cap) {
conn->seq_ack_to_tap = conn->seq_from_tap;
- } else if (conn->seq_ack_to_tap != conn->seq_from_tap) {
- if (!tinfo) {
- tinfo = &tinfo_new;
- if (getsockopt(s, SOL_TCP, TCP_INFO, tinfo, &sl))
- return 0;
- }
-
- conn->seq_ack_to_tap = tinfo->tcpi_bytes_acked +
- conn->seq_init_from_tap;
-
if (SEQ_LT(conn->seq_ack_to_tap, prev_ack_to_tap))
conn->seq_ack_to_tap = prev_ack_to_tap;
+ } else {
+ if ((unsigned)SNDBUF_GET(conn) < SNDBUF_SMALL ||
+ tcp_rtt_dst_low(conn) || CONN_IS_CLOSING(conn) ||
+ (conn->flags & LOCAL) || force_seq) {
+ conn->seq_ack_to_tap = conn->seq_from_tap;
+ } else if (conn->seq_ack_to_tap != conn->seq_from_tap) {
+ if (!tinfo) {
+ tinfo = &tinfo_new;
+ if (getsockopt(s, SOL_TCP, TCP_INFO, tinfo, &sl))
+ return 0;
+ }
+
+ conn->seq_ack_to_tap = tinfo->tcpi_bytes_acked +
+ conn->seq_init_from_tap;
+
+ if (SEQ_LT(conn->seq_ack_to_tap, prev_ack_to_tap))
+ conn->seq_ack_to_tap = prev_ack_to_tap;
+ }
}
-#endif /* !HAS_BYTES_ACKED */
if (!snd_wnd_cap) {
tcp_get_sndbuf(conn);
@@ -2653,6 +2660,12 @@ int tcp_init(struct ctx *c)
#ifdef HAS_SND_WND
dbg_tcpi(snd_wnd);
#endif
+#ifdef HAS_BYTES_ACKED
+ dbg_tcpi(bytes_acked);
+#endif
+#ifdef HAS_MIN_RTT
+ dbg_tcpi(min_rtt);
+#endif
#undef dbg_tcpi
return 0;
--
@@ -380,6 +380,19 @@ socklen_t tcp_info_size;
#else
#define snd_wnd_cap (false)
#endif
+#ifdef HAS_BYTES_ACKED
+/* Does the kernel report bytes acked in TCP_INFO (kernel commit 0df48c26d84) */
+#define bytes_acked_cap tcp_info_cap(bytes_acked)
+#else
+#define bytes_acked_cap (false)
+#endif
+#ifdef HAS_MIN_RTT
+/* Does the kernel report minimum RTT TCP_INFO (kernel commit cd9b266095f4) */
+#define min_rtt_cap tcp_info_cap(min_rtt)
+#else
+#define min_rtt_cap (false)
+#endif
+
/* sendmsg() to socket */
static struct iovec tcp_iov [UIO_MAXIOV];
@@ -687,11 +700,10 @@ static int tcp_rtt_dst_low(const struct tcp_tap_conn *conn)
static void tcp_rtt_dst_check(const struct tcp_tap_conn *conn,
const struct tcp_info *tinfo)
{
-#ifdef HAS_MIN_RTT
const struct flowside *tapside = TAPFLOW(conn);
int i, hole = -1;
- if (!tinfo->tcpi_min_rtt ||
+ if (!min_rtt_cap ||
(int)tinfo->tcpi_min_rtt > LOW_RTT_THRESHOLD)
return;
@@ -712,10 +724,6 @@ static void tcp_rtt_dst_check(const struct tcp_tap_conn *conn,
if (hole == LOW_RTT_TABLE_SIZE)
hole = 0;
inany_from_af(low_rtt_dst + hole, AF_INET6, &in6addr_any);
-#else
- (void)conn;
- (void)tinfo;
-#endif /* HAS_MIN_RTT */
}
/**
@@ -1131,30 +1139,29 @@ int tcp_update_seqack_wnd(const struct ctx *c, struct tcp_tap_conn *conn,
uint32_t new_wnd_to_tap = prev_wnd_to_tap;
int s = conn->sock;
-#ifndef HAS_BYTES_ACKED
- (void)force_seq;
-
- conn->seq_ack_to_tap = conn->seq_from_tap;
- if (SEQ_LT(conn->seq_ack_to_tap, prev_ack_to_tap))
- conn->seq_ack_to_tap = prev_ack_to_tap;
-#else
- if ((unsigned)SNDBUF_GET(conn) < SNDBUF_SMALL || tcp_rtt_dst_low(conn)
- || CONN_IS_CLOSING(conn) || (conn->flags & LOCAL) || force_seq) {
+ if (!bytes_acked_cap) {
conn->seq_ack_to_tap = conn->seq_from_tap;
- } else if (conn->seq_ack_to_tap != conn->seq_from_tap) {
- if (!tinfo) {
- tinfo = &tinfo_new;
- if (getsockopt(s, SOL_TCP, TCP_INFO, tinfo, &sl))
- return 0;
- }
-
- conn->seq_ack_to_tap = tinfo->tcpi_bytes_acked +
- conn->seq_init_from_tap;
-
if (SEQ_LT(conn->seq_ack_to_tap, prev_ack_to_tap))
conn->seq_ack_to_tap = prev_ack_to_tap;
+ } else {
+ if ((unsigned)SNDBUF_GET(conn) < SNDBUF_SMALL ||
+ tcp_rtt_dst_low(conn) || CONN_IS_CLOSING(conn) ||
+ (conn->flags & LOCAL) || force_seq) {
+ conn->seq_ack_to_tap = conn->seq_from_tap;
+ } else if (conn->seq_ack_to_tap != conn->seq_from_tap) {
+ if (!tinfo) {
+ tinfo = &tinfo_new;
+ if (getsockopt(s, SOL_TCP, TCP_INFO, tinfo, &sl))
+ return 0;
+ }
+
+ conn->seq_ack_to_tap = tinfo->tcpi_bytes_acked +
+ conn->seq_init_from_tap;
+
+ if (SEQ_LT(conn->seq_ack_to_tap, prev_ack_to_tap))
+ conn->seq_ack_to_tap = prev_ack_to_tap;
+ }
}
-#endif /* !HAS_BYTES_ACKED */
if (!snd_wnd_cap) {
tcp_get_sndbuf(conn);
@@ -2653,6 +2660,12 @@ int tcp_init(struct ctx *c)
#ifdef HAS_SND_WND
dbg_tcpi(snd_wnd);
#endif
+#ifdef HAS_BYTES_ACKED
+ dbg_tcpi(bytes_acked);
+#endif
+#ifdef HAS_MIN_RTT
+ dbg_tcpi(min_rtt);
+#endif
#undef dbg_tcpi
return 0;
--
2.47.0
next prev parent reply other threads:[~2024-10-23 0:43 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-23 0:42 [PATCH 0/2] tcp: Runtime checks for availability of TCP_INFO fields David Gibson
2024-10-23 0:42 ` [PATCH 1/2] tcp: Generalise probing for tcpi_snd_wnd field David Gibson
2024-10-23 0:42 ` David Gibson [this message]
2024-10-23 7:41 ` [PATCH 2/2] tcp: Use runtime tests for TCP_INFO fields Stefano Brivio
2024-10-24 2:02 ` David Gibson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20241023004253.1729124-3-david@gibson.dropbear.id.au \
--to=david@gibson.dropbear.id.au \
--cc=passt-dev@passt.top \
--cc=sbrivio@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://passt.top/passt
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for IMAP folder(s).