net-snmp: fix failure when starting on system without pci bus

The snmpd daemon cannot start on platforms without a pci bus:

snmpd[15460]: pcilib: Cannot open /proc/bus/pci
snmpd[15460]: pcilib: Cannot find any working access method.

snmpd should not depend on a PCI bus and should simply move on.

Signed-off-by: Jack Mitchell <jack.mitchell@dbbroadcast.co.uk>

meta-oe/recipes-extended/net-snmp/files/ifmib.patch

@@ -0,0 +1,66 @@
+Signed-off-by: Jack Mitchell <jack@embed.me.uk>
+Upstream-Status: Pending
+Bug-Report: http://sourceforge.net/p/net-snmp/bugs/2449/
+
+diff --git a/agent/mibgroup/if-mib/data_access/interface_linux.c b/agent/mibgroup/if-mib/data_access/interface_linux.c
+index 3419811..d6eb91a 100644
+--- a/agent/mibgroup/if-mib/data_access/interface_linux.c
++++ b/agent/mibgroup/if-mib/data_access/interface_linux.c
+@@ -18,7 +18,31 @@ netsnmp_feature_require(interface_ioctl_flags_set)
+ 
+ #ifdef HAVE_PCI_LOOKUP_NAME
+ #include <pci/pci.h>
++#include <setjmp.h>
+ static struct pci_access *pci_access;
++
++/* Avoid letting libpci call exit(1) when no PCI bus is available. */
++static int do_longjmp =0;
++static jmp_buf err_buf;
++static void
++netsnmp_pci_error(char *msg, ...)
++{
++    va_list args;
++    char *buf;
++    int buflen;
++
++    va_start(args, msg);
++    buflen = strlen("pcilib: ")+strlen(msg)+2;
++    buf = malloc(buflen);
++    snprintf(buf, buflen, "pcilib: %s\n", msg);
++    snmp_vlog(LOG_ERR, buf, args);
++    free(buf);
++    va_end(args);
++    if (do_longjmp)
++	longjmp(err_buf, 1);
++    else
++	exit(1);
++}
+ #endif
+ 
+ #ifdef HAVE_LINUX_ETHTOOL_H
+@@ -147,10 +171,22 @@ netsnmp_arch_interface_init(void)
+ 
+ #ifdef HAVE_PCI_LOOKUP_NAME
+     pci_access = pci_alloc();
+-    if (pci_access)
++    if (!pci_access) {
++	snmp_log(LOG_ERR, "pcilib: pci_alloc failed\n");
++	return;
++    }
++
++    pci_access->error = netsnmp_pci_error;
++
++    do_longjmp = 1;
++    if (setjmp(err_buf)) {
++        pci_cleanup(pci_access);
++	snmp_log(LOG_ERR, "pcilib: pci_init failed\n");
++        pci_access = NULL;
++    }
++    else if (pci_access)
+ 	pci_init(pci_access);
+-    else
+-	snmp_log(LOG_ERR, "Unable to create pci access method\n");
++    do_longjmp = 0;
+ #endif
+ }
+ 

meta-oe/recipes-extended/net-snmp/net-snmp_5.7.1.bb

@@ -12,6 +12,7 @@ SRC_URI = "${SOURCEFORGE_MIRROR}/net-snmp/net-snmp-${PV}.tar.gz \
         file://systemd-support.patch \
         file://snmpd.service \
         file://snmptrapd.service \
+        file://ifmib.patch \
 "
 
 EXTRA_OECONF += "--disable-embedded-perl --with-perl-modules=no"