net-snmp/SOURCES/net-snmp-5.8-ipAddress-faster-load.patch
2021-10-08 14:00:55 +00:00

83 lines
2.2 KiB
Diff

diff -urNp a/agent/mibgroup/mibII/ipAddr.c b/agent/mibgroup/mibII/ipAddr.c
--- a/agent/mibgroup/mibII/ipAddr.c 2020-06-10 14:14:30.113696471 +0200
+++ b/agent/mibgroup/mibII/ipAddr.c 2020-06-10 14:27:15.345354018 +0200
@@ -495,14 +495,16 @@ Address_Scan_Next(Index, Retin_ifaddr)
}
#elif defined(linux)
+#include <errno.h>
static struct ifreq *ifr;
static int ifr_counter;
static void
Address_Scan_Init(void)
{
- int num_interfaces = 0;
+ int i;
int fd;
+ int lastlen = 0;
/* get info about all interfaces */
@@ -510,28 +512,45 @@ Address_Scan_Init(void)
SNMP_FREE(ifc.ifc_buf);
ifr_counter = 0;
- do
- {
if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
{
DEBUGMSGTL(("snmpd", "socket open failure in Address_Scan_Init\n"));
return;
}
- num_interfaces += 16;
- ifc.ifc_len = sizeof(struct ifreq) * num_interfaces;
- ifc.ifc_buf = (char*) realloc(ifc.ifc_buf, ifc.ifc_len);
-
- if (ioctl(fd, SIOCGIFCONF, &ifc) < 0)
- {
- ifr=NULL;
- close(fd);
- return;
- }
- close(fd);
+ /*
+ * Cope with lots of interfaces and brokenness of ioctl SIOCGIFCONF
+ * on some platforms; see W. R. Stevens, ``Unix Network Programming
+ * Volume I'', p.435...
+ */
+
+ for (i = 8;; i *= 2) {
+ ifc.ifc_len = sizeof(struct ifreq) * i;
+ ifc.ifc_req = calloc(i, sizeof(struct ifreq));
+
+ if (ioctl(fd, SIOCGIFCONF, &ifc) < 0) {
+ if (errno != EINVAL || lastlen != 0) {
+ /*
+ * Something has gone genuinely wrong...
+ */
+ snmp_log(LOG_ERR, "bad rc from ioctl, errno %d", errno);
+ SNMP_FREE(ifc.ifc_buf);
+ close(fd);
+ return;
+ }
+ } else {
+ if (ifc.ifc_len == lastlen) {
+ /*
+ * The length is the same as the last time; we're done...
+ */
+ break;
+ }
+ lastlen = ifc.ifc_len;
+ }
+ free(ifc.ifc_buf); /* no SNMP_FREE, getting ready to reassign */
}
- while (ifc.ifc_len >= (sizeof(struct ifreq) * num_interfaces));
-
+
+ close(fd);
ifr = ifc.ifc_req;
}