summaryrefslogtreecommitdiff
path: root/src/core/loopback-setup.c
diff options
context:
space:
mode:
authorZbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>2013-03-24 19:59:00 -0400
committerZbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>2013-04-05 19:50:57 -0400
commitb92bea5d2a9481de69bb627a7b442a9f58fca43d (patch)
treed43f5e340014d5c3ce723eabb60cd74e3dd20a18 /src/core/loopback-setup.c
parent8c62ecf1a99ab4a3f69cb81be38715c504ef5723 (diff)
Use initalization instead of explicit zeroing
Before, we would initialize many fields twice: first by filling the structure with zeros, and then a second time with the real values. We can let the compiler do the job for us, avoiding one copy. A downside of this patch is that text gets slightly bigger. This is because all zero() calls are effectively inlined: $ size build/.libs/systemd text data bss dec hex filename before 897737 107300 2560 1007597 f5fed build/.libs/systemd after 897873 107300 2560 1007733 f6075 build/.libs/systemd … actually less than 1‰. A few asserts that the parameter is not null had to be removed. I don't think this changes much, because first, it is quite unlikely for the assert to fail, and second, an immediate SEGV is almost as good as an assert.
Diffstat (limited to 'src/core/loopback-setup.c')
-rw-r--r--src/core/loopback-setup.c65
1 files changed, 31 insertions, 34 deletions
diff --git a/src/core/loopback-setup.c b/src/core/loopback-setup.c
index bfd0d9320..f98a29806 100644
--- a/src/core/loopback-setup.c
+++ b/src/core/loopback-setup.c
@@ -88,25 +88,26 @@ static int add_adresses(int fd, int if_loopback, unsigned *requests) {
union {
struct sockaddr sa;
struct sockaddr_nl nl;
- } sa;
+ } sa = {
+ .nl.nl_family = AF_NETLINK,
+ };
+
union {
struct nlmsghdr header;
uint8_t buf[NLMSG_ALIGN(sizeof(struct nlmsghdr)) +
NLMSG_ALIGN(sizeof(struct ifaddrmsg)) +
RTA_LENGTH(sizeof(struct in6_addr))];
- } request;
+ } request = {
+ .header.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg)),
+ .header.nlmsg_type = RTM_NEWADDR,
+ .header.nlmsg_flags = NLM_F_REQUEST|NLM_F_CREATE|NLM_F_ACK,
+ .header.nlmsg_seq = *requests + 1,
+ };
struct ifaddrmsg *ifaddrmsg;
uint32_t ipv4_address = htonl(INADDR_LOOPBACK);
int r;
- zero(request);
-
- request.header.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg));
- request.header.nlmsg_type = RTM_NEWADDR;
- request.header.nlmsg_flags = NLM_F_REQUEST|NLM_F_CREATE|NLM_F_ACK;
- request.header.nlmsg_seq = *requests + 1;
-
ifaddrmsg = NLMSG_DATA(&request.header);
ifaddrmsg->ifa_family = AF_INET;
ifaddrmsg->ifa_prefixlen = 8;
@@ -114,13 +115,11 @@ static int add_adresses(int fd, int if_loopback, unsigned *requests) {
ifaddrmsg->ifa_scope = RT_SCOPE_HOST;
ifaddrmsg->ifa_index = if_loopback;
- r = add_rtattr(&request.header, sizeof(request), IFA_LOCAL, &ipv4_address, sizeof(ipv4_address));
+ r = add_rtattr(&request.header, sizeof(request), IFA_LOCAL,
+ &ipv4_address, sizeof(ipv4_address));
if (r < 0)
return r;
- zero(sa);
- sa.nl.nl_family = AF_NETLINK;
-
if (sendto_loop(fd, &request, request.header.nlmsg_len, 0, &sa.sa, sizeof(sa)) < 0)
return -errno;
(*requests)++;
@@ -134,7 +133,8 @@ static int add_adresses(int fd, int if_loopback, unsigned *requests) {
ifaddrmsg->ifa_family = AF_INET6;
ifaddrmsg->ifa_prefixlen = 128;
- r = add_rtattr(&request.header, sizeof(request), IFA_LOCAL, &in6addr_loopback, sizeof(in6addr_loopback));
+ r = add_rtattr(&request.header, sizeof(request), IFA_LOCAL,
+ &in6addr_loopback, sizeof(in6addr_loopback));
if (r < 0)
return r;
@@ -149,31 +149,29 @@ static int start_interface(int fd, int if_loopback, unsigned *requests) {
union {
struct sockaddr sa;
struct sockaddr_nl nl;
- } sa;
+ } sa = {
+ .nl.nl_family = AF_NETLINK,
+ };
+
union {
struct nlmsghdr header;
uint8_t buf[NLMSG_ALIGN(sizeof(struct nlmsghdr)) +
NLMSG_ALIGN(sizeof(struct ifinfomsg))];
- } request;
+ } request = {
+ .header.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
+ .header.nlmsg_type = RTM_NEWLINK,
+ .header.nlmsg_flags = NLM_F_REQUEST|NLM_F_ACK,
+ .header.nlmsg_seq = *requests + 1,
+ };
struct ifinfomsg *ifinfomsg;
- zero(request);
-
- request.header.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
- request.header.nlmsg_type = RTM_NEWLINK;
- request.header.nlmsg_flags = NLM_F_REQUEST|NLM_F_ACK;
- request.header.nlmsg_seq = *requests + 1;
-
ifinfomsg = NLMSG_DATA(&request.header);
ifinfomsg->ifi_family = AF_UNSPEC;
ifinfomsg->ifi_index = if_loopback;
ifinfomsg->ifi_flags = IFF_UP;
ifinfomsg->ifi_change = IFF_UP;
- zero(sa);
- sa.nl.nl_family = AF_NETLINK;
-
if (sendto_loop(fd, &request, request.header.nlmsg_len, 0, &sa.sa, sizeof(sa)) < 0)
return -errno;
@@ -234,7 +232,10 @@ static int check_loopback(void) {
union {
struct sockaddr sa;
struct sockaddr_in in;
- } sa;
+ } sa = {
+ .in.sin_family = AF_INET,
+ .in.sin_addr.s_addr = INADDR_LOOPBACK,
+ };
/* If we failed to set up the loop back device, check whether
* it might already be set up */
@@ -243,10 +244,6 @@ static int check_loopback(void) {
if (fd < 0)
return -errno;
- zero(sa);
- sa.in.sin_family = AF_INET;
- sa.in.sin_addr.s_addr = INADDR_LOOPBACK;
-
if (bind(fd, &sa.sa, sizeof(sa.in)) >= 0)
r = 1;
else
@@ -260,7 +257,9 @@ int loopback_setup(void) {
union {
struct sockaddr sa;
struct sockaddr_nl nl;
- } sa;
+ } sa = {
+ .nl.nl_family = AF_NETLINK,
+ };
unsigned requests = 0, i;
int _cleanup_close_ fd = -1;
bool eperm = false;
@@ -274,8 +273,6 @@ int loopback_setup(void) {
if (fd < 0)
return -errno;
- zero(sa);
- sa.nl.nl_family = AF_NETLINK;
if (bind(fd, &sa.sa, sizeof(sa)) < 0) {
r = -errno;
goto error;