check return value of rtnl_send and related functions
Use warn_unused_result to enforce checking return value of rtnl_send,
and fix where the errors are.
Suggested by initial patch from Petr Písař <ppisar@redhat.com>
diff --git a/include/libnetlink.h b/include/libnetlink.h
index ec3d657..fe7d5d3 100644
--- a/include/libnetlink.h
+++ b/include/libnetlink.h
@@ -22,13 +22,22 @@
extern int rcvbuf;
-extern int rtnl_open(struct rtnl_handle *rth, unsigned subscriptions);
-extern int rtnl_open_byproto(struct rtnl_handle *rth, unsigned subscriptions, int protocol);
+extern int rtnl_open(struct rtnl_handle *rth, unsigned subscriptions)
+ __attribute__((warn_unused_result));
+
+extern int rtnl_open_byproto(struct rtnl_handle *rth, unsigned subscriptions,
+ int protocol)
+ __attribute__((warn_unused_result));
+
extern void rtnl_close(struct rtnl_handle *rth);
-extern int rtnl_wilddump_request(struct rtnl_handle *rth, int fam, int type);
+extern int rtnl_wilddump_request(struct rtnl_handle *rth, int fam, int type)
+ __attribute__((warn_unused_result));
extern int rtnl_wilddump_req_filter(struct rtnl_handle *rth, int fam, int type,
- __u32 filt_mask);
-extern int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len);
+ __u32 filt_mask)
+ __attribute__((warn_unused_result));
+extern int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req,
+ int len)
+ __attribute__((warn_unused_result));
typedef int (*rtnl_filter_t)(const struct sockaddr_nl *,
struct nlmsghdr *n, void *);
@@ -44,9 +53,12 @@
extern int rtnl_dump_filter(struct rtnl_handle *rth, rtnl_filter_t filter,
void *arg);
extern int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
- unsigned groups, struct nlmsghdr *answer);
-extern int rtnl_send(struct rtnl_handle *rth, const void *buf, int);
-extern int rtnl_send_check(struct rtnl_handle *rth, const void *buf, int);
+ unsigned groups, struct nlmsghdr *answer)
+ __attribute__((warn_unused_result));
+extern int rtnl_send(struct rtnl_handle *rth, const void *buf, int)
+ __attribute__((warn_unused_result));
+extern int rtnl_send_check(struct rtnl_handle *rth, const void *buf, int)
+ __attribute__((warn_unused_result));
extern int addattr(struct nlmsghdr *n, int maxlen, int type);
extern int addattr8(struct nlmsghdr *n, int maxlen, int type, __u8 data);
diff --git a/ip/iplink.c b/ip/iplink.c
index 58b6c20..e0c14e6 100644
--- a/ip/iplink.c
+++ b/ip/iplink.c
@@ -178,7 +178,10 @@
req.n.nlmsg_type = RTM_NEWLINK;
req.i.ifi_family = AF_UNSPEC;
- rtnl_send(&rth, &req.n, req.n.nlmsg_len);
+ if (rtnl_send(&rth, &req.n, req.n.nlmsg_len) < 0) {
+ perror("request send failed");
+ exit(1);
+ }
rtnl_listen(&rth, accept_msg, NULL);
}
return have_rtnl_newlink;
diff --git a/ip/ipnetconf.c b/ip/ipnetconf.c
index 9a77ecb..37aaf45 100644
--- a/ip/ipnetconf.c
+++ b/ip/ipnetconf.c
@@ -161,7 +161,10 @@
addattr_l(&req.n, sizeof(req), NETCONFA_IFINDEX,
&filter.ifindex, sizeof(filter.ifindex));
- rtnl_send(&rth, &req.n, req.n.nlmsg_len);
+ if (rtnl_send(&rth, &req.n, req.n.nlmsg_len) < 0) {
+ perror("Can not send request");
+ exit(1);
+ }
rtnl_listen(&rth, print_netconf, stdout);
} else {
dump:
diff --git a/misc/arpd.c b/misc/arpd.c
index ec9d570..bfe7de9 100644
--- a/misc/arpd.c
+++ b/misc/arpd.c
@@ -428,7 +428,11 @@
static void load_initial_table(void)
{
- rtnl_wilddump_request(&rth, AF_INET, RTM_GETNEIGH);
+ if (rtnl_wilddump_request(&rth, AF_INET, RTM_GETNEIGH) < 0) {
+ perror("dump request failed");
+ exit(1);
+ }
+
}
static void get_kern_msg(void)
diff --git a/misc/ss.c b/misc/ss.c
index 6f38ae7..e59ca5c 100644
--- a/misc/ss.c
+++ b/misc/ss.c
@@ -996,7 +996,9 @@
static void xll_init(void)
{
struct rtnl_handle rth;
- rtnl_open(&rth, 0);
+ if (rtnl_open(&rth, 0) < 0)
+ exit(1);
+
ll_init_map(&rth);
rtnl_close(&rth);
xll_initted = 1;