journal: fix against (theoretical) undefined behavior

[elogind.git] / src / core / loopback-setup.c

diff --git a/src/core/loopback-setup.c b/src/core/loopback-setup.c
index 7bb20ecabe0395c59f1795c98b4b43ac2817ff4d..d3669e9e32cbc498ef802499ee5cf50b2ebc5226 100644 (file)
--- a/src/core/loopback-setup.c
+++ b/src/core/loopback-setup.c
@@ -47,7 +47,7 @@ static int pipe_handler(sd_rtnl *rtnl, sd_rtnl_message *m, void *userdata) {
         return r == -EEXIST ? 0 : r;
 }
 
-static int add_adresses(sd_rtnl *rtnl, int if_loopback, uint32_t ipv4_address, int *counter) {
+static int add_addresses(sd_rtnl *rtnl, int if_loopback, struct in_addr *ipv4_address, int *counter) {
         _cleanup_sd_rtnl_message_unref_ sd_rtnl_message *ipv4 = NULL, *ipv6 = NULL;
         int r;
 
@@ -55,7 +55,7 @@ static int add_adresses(sd_rtnl *rtnl, int if_loopback, uint32_t ipv4_address, i
         if (r < 0)
                 return r;
 
-        r = sd_rtnl_message_append(ipv4, IFA_LOCAL, &ipv4_address);
+        r = sd_rtnl_message_append_in_addr(ipv4, IFA_LOCAL, ipv4_address);
         if (r < 0)
                 return r;
 
@@ -72,7 +72,7 @@ static int add_adresses(sd_rtnl *rtnl, int if_loopback, uint32_t ipv4_address, i
         if (r < 0)
                 return r;
 
-        r = sd_rtnl_message_append(ipv6, IFA_LOCAL, &in6addr_loopback);
+        r = sd_rtnl_message_append_in6_addr(ipv6, IFA_LOCAL, &in6addr_loopback);
         if (r < 0)
                 return r;
 
@@ -85,11 +85,11 @@ static int add_adresses(sd_rtnl *rtnl, int if_loopback, uint32_t ipv4_address, i
         return 0;
 }
 
-static int start_interface(sd_rtnl *rtnl, int if_loopback, uint32_t ipv4_address, int *counter) {
+static int start_interface(sd_rtnl *rtnl, int if_loopback, struct in_addr *ipv4_address, int *counter) {
         _cleanup_sd_rtnl_message_unref_ sd_rtnl_message *req = NULL;
         int r;
 
-        r = sd_rtnl_message_link_new(RTM_NEWLINK, if_loopback, &req);
+        r = sd_rtnl_message_link_new(RTM_SETLINK, if_loopback, &req);
         if (r < 0)
                 return r;
 
@@ -97,10 +97,6 @@ static int start_interface(sd_rtnl *rtnl, int if_loopback, uint32_t ipv4_address
         if (r < 0)
                 return r;
 
-        r = sd_rtnl_message_append(req, IFA_LOCAL, &ipv4_address);
-        if (r < 0)
-                return r;
-
         r = sd_rtnl_call_async(rtnl, req, &pipe_handler, counter, 0, NULL);
         if (r < 0)
                 return r;
@@ -140,22 +136,24 @@ int loopback_setup(void) {
         _cleanup_sd_rtnl_unref_ sd_rtnl *rtnl = NULL;
         int r, if_loopback, counter = 0;
         bool eperm = false;
-        uint32_t ipv4_address = htonl(INADDR_LOOPBACK);
+        struct in_addr ipv4_address;
 
         errno = 0;
         if_loopback = (int) if_nametoindex("lo");
         if (if_loopback <= 0)
                 return errno ? -errno : -ENODEV;
 
+        ipv4_address.s_addr = htonl(INADDR_LOOPBACK);
+
         r = sd_rtnl_open(0, &rtnl);
         if (r < 0)
                 return r;
 
-        r = add_adresses(rtnl, if_loopback, ipv4_address, &counter);
+        r = add_addresses(rtnl, if_loopback, &ipv4_address, &counter);
         if (r < 0)
                 return r;
 
-        r = start_interface(rtnl, if_loopback, ipv4_address, &counter);
+        r = start_interface(rtnl, if_loopback, &ipv4_address, &counter);
         if (r < 0)
                 return r;