priv: replace the use of `gethostbyname()` by `getaddrinfo()`

`gethostbyname()` was uses to get the canonical name. `getaddrinfo()`
should work even if there is no IPv4 at all in the system.

diff --git a/src/daemon/priv.c b/src/daemon/priv.c
index f660bafda2e4d2291ee30967a1193a9f11e4d843..0d9ea4a2ec62737286b1410d8939f78f5386c2f0 100644 (file)
--- a/src/daemon/priv.c
+++ b/src/daemon/priv.c
@@ -35,7 +35,6 @@
 #include <grp.h>
 #include <sys/utsname.h>
 #include <sys/ioctl.h>
-#include <netdb.h>
 #include <netinet/if_ether.h>
 
 #if defined HOST_OS_FREEBSD || HOST_OS_OSX || HOST_OS_DRAGONFLY
@@ -216,11 +215,14 @@ static void
 asroot_gethostname()
 {
        struct utsname un;
-       struct hostent *hp;
+       struct addrinfo hints = {
+               .ai_flags = AI_CANONNAME
+       };
+       struct addrinfo *res;
        int len;
        if (uname(&un) < 0)
                fatal("privsep", "failed to get system information");
-       if ((hp = gethostbyname(un.nodename)) == NULL) {
+       if (getaddrinfo(un.nodename, NULL, &hints, &res) != 0) {
                log_info("privsep", "unable to get system name");
 #ifdef HAVE_RES_INIT
                res_init();
@@ -229,9 +231,10 @@ asroot_gethostname()
                 must_write(PRIV_PRIVILEGED, &len, sizeof(int));
                 must_write(PRIV_PRIVILEGED, un.nodename, len + 1);
         } else {
-                len = strlen(hp->h_name);
+                len = strlen(res->ai_canonname);
                 must_write(PRIV_PRIVILEGED, &len, sizeof(int));
-                must_write(PRIV_PRIVILEGED, hp->h_name, len + 1);
+                must_write(PRIV_PRIVILEGED, res->ai_canonname, len + 1);
+               freeaddrinfo(res);
         }
 }