Trying to search for memory leaks in my new snmpd code I found some
harmless, but annoying ones in system from SNMPv2-MIB.
We call uname(3) every time (even if we don't even need info from
that call) and ones set we save it until forever.
Diff below calls uname(3) only a single time and if the variables
aren't snmpd.conf I simply rebuild it every time.
I also changed the default "system contact" to an empty string,
since SNMPv2-MIB states:
"If no contact information is known, the value is the zero-length
string."
I've basically never came across a system where there was both
a smtp process accepting remote mail for the root-account and
where the hostname were correctly resolving. If people are really
attached to this value it's easy enough to set it, but I think
it would be better to not tell unfounded assertions.
OK?
martijn@
Index: mib.c
===================================================================
RCS file: /cvs/src/usr.sbin/snmpd/mib.c,v
retrieving revision 1.102
diff -u -p -r1.102 mib.c
--- mib.c 1 Sep 2021 15:54:40 -0000 1.102
+++ mib.c 27 Oct 2021 16:14:15 -0000
@@ -126,22 +126,25 @@ mib_getsys(struct oid *oid, struct ber_o
{
struct ber_oid sysoid = OID(MIB_SYSOID_DEFAULT);
char *s = oid->o_data;
+ char buf[256];
struct ber_oid *so = oid->o_data;
- struct utsname u;
+ static struct utsname u;
+ int init = 0;
long long ticks;
- if (uname(&u) == -1)
- return (-1);
+ if (!init) {
+ if (uname(&u) == -1)
+ return (-1);
+ init = 1;
+ }
switch (oid->o_oid[OIDIDX_system]) {
case 1:
if (s == NULL) {
- if (asprintf(&s, "%s %s %s %s %s",
+ snprintf(buf, sizeof(buf), "%s %s %s %s %s",
u.sysname, u.nodename, u.release,
- u.version, u.machine) == -1)
- return (-1);
- oid->o_data = s;
- oid->o_val = strlen(s);
+ u.version, u.machine);
+ s = buf;
}
*elm = ober_add_string(*elm, s);
break;
@@ -157,21 +160,13 @@ mib_getsys(struct oid *oid, struct ber_o
ober_set_header(*elm, BER_CLASS_APPLICATION, SNMP_T_TIMETICKS);
break;
case 4:
- if (s == NULL) {
- if (asprintf(&s, "root@%s", u.nodename) == -1)
- return (-1);
- oid->o_data = s;
- oid->o_val = strlen(s);
- }
+ if (s == NULL)
+ s = "";
*elm = ober_add_string(*elm, s);
break;
case 5:
- if (s == NULL) {
- if ((s = strdup(u.nodename)) == NULL)
- return (-1);
- oid->o_data = s;
- oid->o_val = strlen(s);
- }
+ if (s == NULL)
+ s = u.nodename;
*elm = ober_add_string(*elm, s);
break;
case 6:
Index: snmpd.conf.5
===================================================================
RCS file: /cvs/src/usr.sbin/snmpd/snmpd.conf.5,v
retrieving revision 1.58
diff -u -p -r1.58 snmpd.conf.5
--- snmpd.conf.5 2 Sep 2021 05:41:02 -0000 1.58
+++ snmpd.conf.5 27 Oct 2021 16:14:15 -0000
@@ -244,9 +244,6 @@ This is the default value.
.It Ic system contact Ar string
Specify the name or description of the system contact, typically a
name or an email address.
-The default value is
-.Ar root@hostname
-using the hostname of the local machine.
.It Ic system description Ar string
Specify a description of the local system.
The default value is the operating system identification as printed by the
