Re: [PATCH v2 16/23] conf: Move "all" handling to port specifier

On Thu, Apr 16, 2026 at 12:04:43AM +0200, Stefano Brivio wrote:

On Fri, 10 Apr 2026 11:03:02 +1000 David Gibson wrote:

...

Currently -[tTuU] all is handled separately in conf_ports() before calling conf_ports_spec(). Earlier changes mean we can now move this handling to conf_ports_spec(). This makes the code slightly simpler, but more importantly it allows some useful combinations we couldn't previously do, such as -t 127.0.0.1/all or -u %eth2/all

Signed-off-by: David Gibson --- conf.c | 25 ++++++++++--------------- passt.1 | 28 ++++++++++++++++++++-------- 2 files changed, 30 insertions(+), 23 deletions(-)

diff --git a/conf.c b/conf.c index 5d6517c3..f62109b5 100644 --- a/conf.c +++ b/conf.c @@ -251,6 +251,11 @@ static void conf_ports_spec(const struct ctx *c, const char *p, *ep; unsigned i;

+ if (!strcmp(spec, "all")) { + /* Treat "all" as equivalent to "": all non-ephemeral ports */ + spec = ""; + } + /* Mark all exclusions first, they might be given after base ranges */ for_each_chunk(p, ep, spec, ",") { struct port_range xrange; @@ -372,19 +377,6 @@ static void conf_ports(const struct ctx *c, char optname, const char *optarg, return; }

- if (!strcmp(optarg, "all")) { - uint8_t exclude[PORT_BITMAP_SIZE] = { 0 }; - - /* Exclude ephemeral ports */ - fwd_port_map_ephemeral(exclude); - - conf_ports_range_except(c, optname, optarg, fwd, - proto, NULL, NULL, - 1, NUM_PORTS - 1, exclude, - 1, FWD_WEAK); - return; - } - strncpy(buf, optarg, sizeof(buf) - 1);

if ((spec = strchr(buf, '/'))) { @@ -1039,14 +1031,17 @@ static void usage(const char *name, FILE *f, int status) " can be specified multiple times\n" " SPEC can be:\n" " 'none': don't forward any ports\n" - " 'all': forward all unbound, non-ephemeral ports\n" "%s" " [ADDR[%%IFACE]/]PORTS: forward specific ports\n" - " PORTS is a comma-separated list of ports, optionally\n" + " PORTS is either 'all' (forward all unbound, non-ephemeral\n" + " ports), or a comma-separated list of ports, optionally\n" " ranged with '-' and optional target ports after ':'.\n" " Ranges can be reduced by excluding ports or ranges\n" " prefixed by '~'\n" " Examples:\n" + " -t all Forward all ports\n"

Nit: the examples below have a tab as a separator, which makes it slightly easier to ensure we indent them properly.

Oops, fixed.

...

+ " -t 127.0.0.1/all Forward all ports from local address\n" + " 127.0.0.1\n"

This makes things pretty hard on eyes as it's not consistent with the rest of the "table". Could we perhaps do:

" -t ::1/all Forward all ports from ::1\n"

?

Ah, good idea. Done.

...

" -t 22 Forward local port 22 to 22 on %s\n" " -t 22:23 Forward local port 22 to 23 on %s\n" " -t 22,25 Forward ports 22, 25 to ports 22, 25\n" diff --git a/passt.1 b/passt.1 index d329f8f0..3ba447d5 100644 --- a/passt.1 +++ b/passt.1 @@ -434,12 +434,6 @@ Configure TCP port forwarding to guest or namespace. \fIspec\fR can be one of: .BR none Don't forward any ports

-.TP -.BR all -Forward all unbound, non-ephemeral ports, as permitted by current capabilities. -For low (< 1024) ports, see \fBNOTES\fR. No failures are reported for -unavailable ports, unless no ports could be forwarded at all. - .TP .BR auto " " (\fBpasta\fR " " only) Dynamically forward ports bound in the namespace. The list of ports is @@ -449,10 +443,20 @@ periodically derived (every second) from listening sockets reported by .TP [\fIaddress\fR[\fB%\fR\fIinterface\fR]\fB/\fR]\fIports\fR ... Specific ports to forward. Optionally, a specific listening address -and interface name (since Linux 5.7) can be specified. \fIports\fR is -a comma-separated list of entries which may be any of: +and interface name (since Linux 5.7) can be specified. \fIports\fR +may be either: .RS .TP +\fBall\fR +Forward all unbound, non-ephemeral ports, as permitted by current +capabilities. For low (< 1024) ports, see \fBNOTES\fR. No failures +are reported for unavailable ports, unless no ports could be forwarded +at all. +.RE + +.RS +or a comma-separated list of entries which may be any of: +.TP \fIfirst\fR[\fB-\fR\fIlast\fR][\fB:\fR\fItofirst\fR[\fB-\fR\fItolast\fR]] Include range. Forward port numbers between \fIfirst\fR and \fIlast\fR (inclusive) to ports between \fItofirst\fR and \fItolast\fR. If @@ -473,6 +477,14 @@ unavailable ports, unless no ports could be forwarded at all. Examples: .RS .TP +-t all +Forward all unbound, non-ephemeral ports as permitted by current +capabilities to the corresponding port on the guest or namespace +.TP +-t 127.0.0.1/all +For the local address 127.0.0.1, forward all unbound, non-ephemeral +ports as permitted by current capabilities.

Nit: all the other examples have no dot at the end (I tend to think it fits better this type of list, but all I care about is that it's consistent).

Fixed. Also changed to ::1 for consistency with the usage() example.

...

+.TP -t 22 Forward local port 22 to port 22 on the guest or namespace .TP

-- Stefano

-- David Gibson (he or they) | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you, not the other way | around. http://www.ozlabs.org/~dgibson