From: David Gibson <david@gibson.dropbear.id.au>
To: passt-dev@passt.top, Stefano Brivio <sbrivio@redhat.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCH 5/8] fwd: Share port scanning logic between init and timer cases
Date: Sat, 11 Oct 2025 15:48:24 +1100 [thread overview]
Message-ID: <20251011044827.862757-6-david@gibson.dropbear.id.au> (raw)
In-Reply-To: <20251011044827.862757-1-david@gibson.dropbear.id.au>
When using -t auto and the like, we scan for listening ports once at
startup, then repeatedly on a timer. With previous rearrangements the
logic for each of these cases is very nearly repeated. Factor it out into
a fwd_scan_ports() function.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
fwd.c | 40 ++++++++++++++++++++++------------------
1 file changed, 22 insertions(+), 18 deletions(-)
diff --git a/fwd.c b/fwd.c
index c7b768d5..6f89acf5 100644
--- a/fwd.c
+++ b/fwd.c
@@ -191,6 +191,26 @@ static void fwd_scan_ports_udp(struct fwd_ports *fwd,
bitmap_andc(fwd->map, PORT_BITMAP_SIZE, fwd->map, tcp_rev->map);
}
+/**
+ * fwd_scan_ports() - Scan automatic port forwarding information
+ * @c: Execution context
+ */
+static void fwd_scan_ports(struct ctx *c)
+{
+ if (c->tcp.fwd_out.mode == FWD_AUTO)
+ fwd_scan_ports_tcp(&c->tcp.fwd_out, &c->tcp.fwd_in);
+ if (c->tcp.fwd_in.mode == FWD_AUTO)
+ fwd_scan_ports_tcp(&c->tcp.fwd_in, &c->tcp.fwd_out);
+ if (c->udp.fwd_out.mode == FWD_AUTO) {
+ fwd_scan_ports_udp(&c->udp.fwd_out, &c->udp.fwd_in,
+ &c->tcp.fwd_out, &c->tcp.fwd_in);
+ }
+ if (c->udp.fwd_in.mode == FWD_AUTO) {
+ fwd_scan_ports_udp(&c->udp.fwd_in, &c->udp.fwd_out,
+ &c->tcp.fwd_in, &c->tcp.fwd_out);
+ }
+}
+
/**
* fwd_scan_ports_init() - Initial setup for automatic port forwarding
* @c: Execution context
@@ -207,25 +227,20 @@ void fwd_scan_ports_init(struct ctx *c)
if (c->tcp.fwd_in.mode == FWD_AUTO) {
c->tcp.fwd_in.scan4 = open_in_ns(c, "/proc/net/tcp", flags);
c->tcp.fwd_in.scan6 = open_in_ns(c, "/proc/net/tcp6", flags);
- fwd_scan_ports_tcp(&c->tcp.fwd_in, &c->tcp.fwd_out);
}
if (c->udp.fwd_in.mode == FWD_AUTO) {
c->udp.fwd_in.scan4 = open_in_ns(c, "/proc/net/udp", flags);
c->udp.fwd_in.scan6 = open_in_ns(c, "/proc/net/udp6", flags);
- fwd_scan_ports_udp(&c->udp.fwd_in, &c->udp.fwd_out,
- &c->tcp.fwd_in, &c->tcp.fwd_out);
}
if (c->tcp.fwd_out.mode == FWD_AUTO) {
c->tcp.fwd_out.scan4 = open("/proc/net/tcp", flags);
c->tcp.fwd_out.scan6 = open("/proc/net/tcp6", flags);
- fwd_scan_ports_tcp(&c->tcp.fwd_out, &c->tcp.fwd_in);
}
if (c->udp.fwd_out.mode == FWD_AUTO) {
c->udp.fwd_out.scan4 = open("/proc/net/udp", flags);
c->udp.fwd_out.scan6 = open("/proc/net/udp6", flags);
- fwd_scan_ports_udp(&c->udp.fwd_out, &c->udp.fwd_in,
- &c->tcp.fwd_out, &c->tcp.fwd_in);
}
+ fwd_scan_ports(c);
}
/* Last time we scanned for open ports */
@@ -246,18 +261,7 @@ void fwd_scan_ports_timer(struct ctx *c, const struct timespec *now)
scan_ports_run = *now;
- if (c->tcp.fwd_out.mode == FWD_AUTO)
- fwd_scan_ports_tcp(&c->tcp.fwd_out, &c->tcp.fwd_in);
- if (c->tcp.fwd_in.mode == FWD_AUTO)
- fwd_scan_ports_tcp(&c->tcp.fwd_in, &c->tcp.fwd_out);
- if (c->udp.fwd_out.mode == FWD_AUTO) {
- fwd_scan_ports_udp(&c->udp.fwd_out, &c->udp.fwd_in,
- &c->tcp.fwd_out, &c->tcp.fwd_in);
- }
- if (c->udp.fwd_in.mode == FWD_AUTO) {
- fwd_scan_ports_udp(&c->udp.fwd_in, &c->udp.fwd_out,
- &c->tcp.fwd_in, &c->tcp.fwd_out);
- }
+ fwd_scan_ports(c);
if (!c->no_tcp)
tcp_port_rebind_all(c);
--
2.51.0
next prev parent reply other threads:[~2025-10-11 4:49 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-11 4:48 [PATCH 0/8] RFC: Cleanups to auto port scanning David Gibson
2025-10-11 4:48 ` [PATCH 1/8] icmp: Remove vestiges of ICMP timer David Gibson
2025-10-11 4:48 ` [PATCH 2/8] tcp, udp, fwd: Run all port scanning from a single timer David Gibson
2025-10-11 4:48 ` [PATCH 3/8] fwd: Consolidate scans (not rebinds) in fwd.c David Gibson
2025-10-11 4:48 ` [PATCH 4/8] fwd: Move port exclusion handling from procfs_scan_listen() to callers David Gibson
2025-10-11 4:48 ` David Gibson [this message]
2025-10-11 4:48 ` [PATCH 6/8] fwd: Check forwarding mode in fwd_scan_ports_*() rather than caller David Gibson
2025-10-11 4:48 ` [PATCH 7/8] fwd: Update all port maps before applying exclusions David Gibson
2025-10-11 4:48 ` [PATCH 8/8] tcp, udp: Don't exclude ports in {tcp,udp}_port_rebind() David Gibson
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