From: Luigi Rizzo <luigi@freebsd.org>
Date: Thu, 2 Oct 2014 21:34:52 +0000 (+0000)
Subject: add CAP_EVENT for the libpcap device
X-Git-Tag: tcpdump-4.99-bp~2092
X-Git-Url: https://git.tcpdump.org/tcpdump/commitdiff_plain/8830c2865ebfa133d526771a5ade95c870aab560?ds=sidebyside

add CAP_EVENT for the libpcap device

...so we will be able to use pcap-netmap, which does poll() on the file
descriptor.
---

diff --git a/tcpdump.c b/tcpdump.c
index 73bf1387..e26fbafd 100644
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -1855,7 +1855,12 @@ main(int argc, char **argv)
 	if (RFileName == NULL && VFileName == NULL) {
 		static const unsigned long cmds[] = { BIOCGSTATS, BIOCROTZBUF };
 
-		cap_rights_init(&rights, CAP_IOCTL, CAP_READ);
+		/*
+		 * The various libpcap devices use a combination of
+		 * read (bpf), ioctl (bpf, netmap), poll (netmap)
+		 * so we add the relevant access rights.
+		 */
+		cap_rights_init(&rights, CAP_IOCTL, CAP_READ, CAP_EVENT);
 		if (cap_rights_limit(pcap_fileno(pd), &rights) < 0 &&
 		    errno != ENOSYS) {
 			error("unable to limit pcap descriptor");