dpdk: suppress -Wformat-truncation warnings.

This doesn't fix them - nothing short of changing the way we generate
error message strings will do that - but at least it means we don't get
annoyed by them, and it also marks places that would need to be changed
if we change the way we generate those error message strings. See #1544
for an issue for making those changes.

This addresses part of #1543.

Author: guyharris

pcap-dpdk.c

@@ -112,6 +112,8 @@ env DPDK_CFG="--log-level=debug -l0 -dlibrte_pmd_e1000.so -dlibrte_pmd_ixgbe.so
 #include <rte_bus.h>
 #include <rte_version.h>
 
+#include "diag-control.h"
+
 #include "pcap-int.h"
 #include "pcap-dpdk.h"
 
@@ -781,18 +783,22 @@ static int pcap_dpdk_activate(pcap_t *p)
 		if (ret < 0)
 		{
 			// This returns a negative value on an error.
+DIAG_OFF_FORMAT_TRUNCATION
 			snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
 			    "Can't open device %s: %s",
 			    p->opt.device, dpdk_pre_init_errbuf);
+DIAG_ON_FORMAT_TRUNCATION
 			// ret is set to the correct error
 			break;
 		}
 		if (ret == 0)
 		{
 			// This means DPDK isn't available on this machine.
+DIAG_OFF_FORMAT_TRUNCATION
 			snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
 			    "Can't open device %s: DPDK is not available on this machine",
 			    p->opt.device);
+DIAG_ON_FORMAT_TRUNCATION
 			return PCAP_ERROR_NO_SUCH_DEVICE;
 		}
 
@@ -809,17 +815,21 @@ static int pcap_dpdk_activate(pcap_t *p)
 		nb_ports = rte_eth_dev_count_avail();
 		if (nb_ports == 0)
 		{
+DIAG_OFF_FORMAT_TRUNCATION
 			snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
 			    "dpdk error: No Ethernet ports");
+DIAG_ON_FORMAT_TRUNCATION
 			ret = PCAP_ERROR;
 			break;
 		}
 
 		portid = portid_by_device(p->opt.device);
 		if (portid == DPDK_PORTID_MAX){
+DIAG_OFF_FORMAT_TRUNCATION
 			snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
 			    "dpdk error: portid is invalid. device %s",
 			    p->opt.device);
+DIAG_ON_FORMAT_TRUNCATION
 			ret = PCAP_ERROR_NO_SUCH_DEVICE;
 			break;
 		}
@@ -836,9 +846,11 @@ static int pcap_dpdk_activate(pcap_t *p)
 			rte_socket_id());
 		if (pd->pktmbuf_pool == NULL)
 		{
+DIAG_OFF_FORMAT_TRUNCATION
 			dpdk_fmt_errmsg_for_rte_errno(p->errbuf,
 			    PCAP_ERRBUF_SIZE, rte_errno,
 			    "dpdk error: Cannot init mbuf pool");
+DIAG_ON_FORMAT_TRUNCATION
 			ret = PCAP_ERROR;
 			break;
 		}
@@ -919,8 +931,10 @@ static int pcap_dpdk_activate(pcap_t *p)
 				rte_eth_dev_socket_id(portid));
 		if (tx_buffer == NULL)
 		{
+DIAG_OFF_FORMAT_TRUNCATION
 			snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
 			    "dpdk error: Cannot allocate buffer for tx on port %u", portid);
+DIAG_ON_FORMAT_TRUNCATION
 			ret = PCAP_ERROR;
 			break;
 		}
@@ -944,8 +958,10 @@ static int pcap_dpdk_activate(pcap_t *p)
 		// check link status
 		is_port_up = check_link_status(portid, &link);
 		if (!is_port_up){
+DIAG_OFF_FORMAT_TRUNCATION
 			snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
 			    "dpdk error: link is down, port=%u",portid);
+DIAG_ON_FORMAT_TRUNCATION
 			ret = PCAP_ERROR_IFACE_NOT_UP;
 			break;
 		}
@@ -1033,9 +1049,11 @@ int pcap_dpdk_findalldevs(pcap_if_list_t *devlistp, char *ebuf)
 		if (ret < 0)
 		{
 			// This returns a negative value on an error.
+DIAG_OFF_FORMAT_TRUNCATION
 			snprintf(ebuf, PCAP_ERRBUF_SIZE,
 			    "Can't look for DPDK devices: %s",
 			    dpdk_pre_init_errbuf);
+DIAG_ON_FORMAT_TRUNCATION
 			ret = PCAP_ERROR;
 			break;
 		}