res_send: use a temp buffer if caller's buffer is under 512 bytes

[musl] / src / network / inet_ntop.c

diff --git a/src/network/inet_ntop.c b/src/network/inet_ntop.c
index 4817187..4bfef2c 100644 (file)
--- a/src/network/inet_ntop.c
+++ b/src/network/inet_ntop.c
@@ -1,12 +1,10 @@
 #include <sys/socket.h>
-#include <netinet/in.h>
 #include <arpa/inet.h>
-#include <netdb.h>
 #include <errno.h>
 #include <stdio.h>
 #include <string.h>
 
-const char *inet_ntop(int af, const void *a0, char *s, socklen_t l)
+const char *inet_ntop(int af, const void *restrict a0, char *restrict s, socklen_t l)
 {
        const unsigned char *a = a0;
        int i, j, max, best;
@@ -18,23 +16,29 @@ const char *inet_ntop(int af, const void *a0, char *s, socklen_t l)
                        return s;
                break;
        case AF_INET6:
-               memset(buf, 'x', sizeof buf);
-               buf[sizeof buf-1]=0;
-               snprintf(buf, sizeof buf,
-                       "%x:%x:%x:%x:%x:%x:%x:%x",
-                       256*a[0]+a[1],256*a[2]+a[3],
-                       256*a[4]+a[5],256*a[6]+a[7],
-                       256*a[8]+a[9],256*a[10]+a[11],
-                       256*a[12]+a[13],256*a[14]+a[15]);
+               if (memcmp(a, "\0\0\0\0\0\0\0\0\0\0\377\377", 12))
+                       snprintf(buf, sizeof buf,
+                               "%x:%x:%x:%x:%x:%x:%x:%x",
+                               256*a[0]+a[1],256*a[2]+a[3],
+                               256*a[4]+a[5],256*a[6]+a[7],
+                               256*a[8]+a[9],256*a[10]+a[11],
+                               256*a[12]+a[13],256*a[14]+a[15]);
+               else
+                       snprintf(buf, sizeof buf,
+                               "%x:%x:%x:%x:%x:%x:%d.%d.%d.%d",
+                               256*a[0]+a[1],256*a[2]+a[3],
+                               256*a[4]+a[5],256*a[6]+a[7],
+                               256*a[8]+a[9],256*a[10]+a[11],
+                               a[12],a[13],a[14],a[15]);
                /* Replace longest /(^0|:)[:0]{2,}/ with "::" */
                for (i=best=0, max=2; buf[i]; i++) {
                        if (i && buf[i] != ':') continue;
                        j = strspn(buf+i, ":0");
                        if (j>max) best=i, max=j;
                }
-               if (max>2) {
+               if (max>3) {
                        buf[best] = buf[best+1] = ':';
-                       strcpy(buf+best+2, buf+best+max);
+                       memmove(buf+best+2, buf+best+max, i-best-max+1);
                }
                if (strlen(buf) < l) {
                        strcpy(s, buf);