From: Guy Harris <guy@alum.mit.edu>
Date: Mon, 4 Apr 2011 16:57:18 +0000 (-0700)
Subject: Handle older kernels that don't define PACKET_RESERVE.
X-Git-Tag: libpcap-1.2.1~66
X-Git-Url: https://git.tcpdump.org/libpcap/commitdiff_plain/dad71a62725eb07eb2470abfca1420aaa7299432?ds=sidebyside

Handle older kernels that don't define PACKET_RESERVE.
---

diff --git a/pcap-linux.c b/pcap-linux.c
index 638b1c00..8e394f4f 100644
--- a/pcap-linux.c
+++ b/pcap-linux.c
@@ -3196,12 +3196,16 @@ create_ring(pcap_t *handle, int *status)
 		*status = PCAP_ERROR;
 		return -1;
 	}
+#ifdef PACKET_RESERVE
 	len = sizeof(tp_reserve);
 	if (getsockopt(handle->fd, SOL_PACKET, PACKET_RESERVE, &tp_reserve, &len) < 0) {
 		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "getsockopt: %s", pcap_strerror(errno));
 		*status = PCAP_ERROR;
 		return -1;
 	}
+#else
+	tp_reserve = 0;	/* older kernel, reserve not supported */
+#endif
 	maclen = (sk_type == SOCK_DGRAM) ? 0 : MAX_LINKHEADER_SIZE;
 		/* XXX: in the kernel maclen is calculated from
 		 * LL_ALLOCATED_SPACE(dev) and vnet_hdr.hdr_len