net-snmp: backport signal patch

Fixes compilation with uClibc-ng.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

net/net-snmp/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=net-snmp
 PKG_VERSION:=5.8
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=@SF/net-snmp

net/net-snmp/patches/910-signal.patch

@@ -0,0 +1,147 @@
+From 1ee70571e0cae37f155f59d4382bc7109138cf09 Mon Sep 17 00:00:00 2001
+From: Bart Van Assche <bvanassche@acm.org>
+Date: Sat, 15 Aug 2020 17:29:25 -0700
+Subject: [PATCH] apps/snmpnetstat: Stop using obsolete signal functions
+
+This was reported by Rosen Penev. See also
+https://github.com/net-snmp/net-snmp/pull/162.
+---
+ apps/snmpnetstat/if.c | 111 +++++++++++-------------------------------
+ 1 file changed, 28 insertions(+), 83 deletions(-)
+ mode change 100644 => 100755 apps/snmpnetstat/if.c
+
+diff --git a/apps/snmpnetstat/if.c b/apps/snmpnetstat/if.c
+old mode 100644
+new mode 100755
+index 16768151d..84b87b531
+--- a/apps/snmpnetstat/if.c
++++ b/apps/snmpnetstat/if.c
+@@ -64,8 +64,6 @@
+ #define	NO	0
+ 
+ static void sidewaysintpr(u_int);
+-static void timerSet(int interval_seconds);
+-static void timerPause(void);
+ 
+     struct _if_info {
+         char            name[128];
+@@ -92,6 +90,34 @@ static void timerPause(void);
+     };
+ 
+ 
++static struct timeval deadline;
++
++static void
++timerSet(int interval_seconds)
++{
++    const struct timeval interval = { interval_seconds, 0 };
++
++    netsnmp_get_monotonic_clock(&deadline);
++    NETSNMP_TIMERADD(&deadline, &interval, &deadline);
++}
++
++static void
++timerPause(void)
++{
++    struct timeval now, delta;
++
++    netsnmp_get_monotonic_clock(&now);
++    NETSNMP_TIMERSUB(&deadline, &now, &delta);
++    if (delta.tv_sec < 0)
++        return;
++#ifdef WIN32
++    Sleep(delta.tv_sec * 1000 + delta.tv_usec / 1000);
++#else
++    if (select(0, NULL, NULL, NULL, &delta) < 0)
++        snmp_perror("select");
++#endif
++}
++
+ /*
+  * Retrieve the interface addressing information
+  * XXX - This could also be extended to handle non-IP interfaces
+@@ -845,84 +871,3 @@ sidewaysintpr(unsigned int interval)
+     	goto loop;
+     /*NOTREACHED*/
+ }
+-
+-
+-/*
+- * timerSet sets or resets the timer to fire in "interval" seconds.
+- * timerPause waits only if the timer has not fired.
+- * timing precision is not considered important.
+- */
+-
+-#if (defined(WIN32) || defined(cygwin))
+-static int      sav_int;
+-static time_t   timezup;
+-static void
+-timerSet(int interval_seconds)
+-{
+-    sav_int = interval_seconds;
+-    timezup = time(0) + interval_seconds;
+-}
+-
+-/*
+- * you can do better than this ! 
+- */
+-static void
+-timerPause(void)
+-{
+-    time_t          now;
+-    while (time(&now) < timezup)
+-#ifdef WIN32
+-        Sleep(400);
+-#else
+-    {
+-        struct timeval  tx;
+-        tx.tv_sec = 0;
+-        tx.tv_usec = 400 * 1000;        /* 400 milliseconds */
+-        select(0, 0, 0, 0, &tx);
+-    }
+-#endif
+-}
+-
+-#else
+-
+-/*
+- * Called if an interval expires before sidewaysintpr has completed a loop.
+- * Sets a flag to not wait for the alarm.
+- */
+-RETSIGTYPE
+-catchalarm(int sig)
+-{
+-    signalled = YES;
+-}
+-
+-static void
+-timerSet(int interval_seconds)
+-{
+-#ifdef HAVE_SIGSET
+-    (void) sigset(SIGALRM, catchalarm);
+-#else
+-    (void) signal(SIGALRM, catchalarm);
+-#endif
+-    signalled = NO;
+-    (void) alarm(interval_seconds);
+-}
+-
+-static void
+-timerPause(void)
+-{
+-#ifdef HAVE_SIGHOLD
+-    sighold(SIGALRM);
+-    if (!signalled) {
+-        sigpause(SIGALRM);
+-    }
+-#else
+-    int             oldmask;
+-    oldmask = sigblock(sigmask(SIGALRM));
+-    if (!signalled) {
+-        sigpause(0);
+-    }
+-    sigsetmask(oldmask);
+-#endif
+-}
+-
+-#endif                          /* !WIN32 && !cygwin */