Re: sshd proctitle [Re: CVS: cvs.openbsd.org: src]

[Damien Miller]

On Thu, 23 Jan 2020, Damien Miller wrote:

> On Wed, 22 Jan 2020, Stuart Henderson wrote:
> 
> > On 2020/01/21 15:39, Damien Miller wrote:
> > > CVSROOT:  /cvs
> > > Module name:      src
> > > Changes by:       d...@cvs.openbsd.org    2020/01/21 15:39:57
> > > 
> > > Modified files:
> > >   usr.bin/ssh    : sshd.c 
> > > 
> > > Log message:
> > > expose the number of currently-authenticating connections
> > > along with the MaxStartups limit in the proctitle;
> > > suggestion from Philipp Marek, w/ feedback from Craig Miskell
> > > ok dtucker@
> > > 
> > 
> > It's nice to have this information visible, but it brings some problems.
> > You can't now distinguish between multiple sshd processes (e.g. if you
> > run several on different ports it's hard to figure out which one to
> > signal if needed).
> 
> How could you discern between different sshd processes before? Just the
> command-line args?
> 
> What information would you like there? We could put the first N listen
> addrs in the proctitle if that would help.

Maybe like this:

63817 ??  S        0:00.05 sshd: [listen] on [0.0.0.0]:22, [::]:22, 0 of 10-100

ok?

diff --git a/sshd.c b/sshd.c
index ec644c9..15014d1 100644
--- a/sshd.c
+++ b/sshd.c
@@ -240,6 +240,9 @@ void destroy_sensitive_data(void);
 void demote_sensitive_data(void);
 static void do_ssh2_kex(struct ssh *);
 
+/* Listen info for proctitle */
+static char *proctitle_listen_addr;
+
 /*
  * Close all listening sockets
  */
@@ -913,7 +916,7 @@ listen_on_addrs(struct listenaddr *la)
 {
        int ret, listen_sock;
        struct addrinfo *ai;
-       char ntop[NI_MAXHOST], strport[NI_MAXSERV];
+       char *cp, ntop[NI_MAXHOST], strport[NI_MAXSERV];
 
        for (ai = la->addrs; ai; ai = ai->ai_next) {
                if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
@@ -973,6 +976,15 @@ listen_on_addrs(struct listenaddr *la)
                    ntop, strport,
                    la->rdomain == NULL ? "" : " rdomain ",
                    la->rdomain == NULL ? "" : la->rdomain);
+               if (num_listen_socks < 3) {
+                       cp = proctitle_listen_addr;
+                       xasprintf(&proctitle_listen_addr, "%s%s[%s]:%s%s%s",
+                           cp == NULL ? "" : cp, cp == NULL ? "" : ", ",
+                           ntop, strport,
+                           la->rdomain == NULL ? "" : " rdomain ",
+                           la->rdomain == NULL ? "" : la->rdomain);
+                       free(cp);
+               }
        }
 }
 
@@ -1030,7 +1042,9 @@ server_accept_loop(int *sock_in, int *sock_out, int 
*newsock, int *config_s)
         */
        for (;;) {
                if (ostartups != startups) {
-                       setproctitle("[listener] %d of %d-%d startups",
+                       setproctitle("[listen] on %s%s, "
+                           "%d of %d-%d startups", proctitle_listen_addr,
+                           num_listen_socks > 3 ? " [...]" : "",
                            startups, options.max_startups_begin,
                            options.max_startups);
                        ostartups = startups;