flowtop: Don't attempt to set sysctl values if initial read fails

Bail out early if we fail to read the current sysctl variable values for
net/netfilter/nf_conntrack_acct and net/netfilter/nf_conntrack_timestamp

Otherwise we'll not be able restore the previous value on exit/panic.
Moreover, if we fail to read the sysctl file, we usually also lack the
permissions to write it.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

1 files changed, 2 insertions, 0 deletions

diff --git a/flowtop.c b/flowtop.c
index 0d36a0a..9df4bdb 100644
--- a/flowtop.c
+++ b/flowtop.c
@@ -1132,6 +1132,7 @@ static void conntrack_acct_enable(void)
 	if (sysctl_get_int("net/netfilter/nf_conntrack_acct", &sysctl.nfct_acct)) {
 		fprintf(stderr, "Can't read net/netfilter/nf_conntrack_acct: %s\n",
 			strerror(errno));
+		return;
 	}
 
 	if (sysctl.nfct_acct == 1)
@@ -1148,6 +1149,7 @@ static void conntrack_tstamp_enable(void)
 	if (sysctl_get_int("net/netfilter/nf_conntrack_timestamp", &sysctl.nfct_tstamp)) {
 		fprintf(stderr, "Can't read net/netfilter/nf_conntrack_timestamp: %s\n",
 			strerror(errno));
+		return;
 	}
 
 	if (sysctl.nfct_tstamp == 1)