add ether_aton[_r] and ether_ntoa[_r] functions

based on patch by Strake with minor stylistic changes, and combined
into a single file. this patch remained open for a long time due to
some question as to whether ether_aton would be better implemented in
terms of sscanf, and it's time something was committed, so here it is.

diff --git a/include/netinet/ether.h b/include/netinet/ether.h
new file mode 100644 (file)
index 0000000..c5179d5
--- /dev/null
+++ b/include/netinet/ether.h
@@ -0,0 +1,14 @@
+#ifndef _NETINET_ETHER_H
+#define _NETINET_ETHER_H
+
+#include <netinet/if_ether.h>
+
+char *ether_ntoa (const struct ether_addr *);
+
+struct ether_addr *ether_aton (const char *);
+
+char *ether_ntoa_r (const struct ether_addr *, char *);
+
+struct ether_addr *ether_aton_r (const char *, struct ether_addr *);
+
+#endif

diff --git a/src/network/ether.c b/src/network/ether.c
new file mode 100644 (file)
index 0000000..ac55411
--- /dev/null
+++ b/src/network/ether.c
@@ -0,0 +1,43 @@
+#include <stdlib.h>
+#include <netinet/ether.h>
+#include <stdio.h>
+
+struct ether_addr *ether_aton_r (const char *x, struct ether_addr *p_a)
+{
+       struct ether_addr a;
+       char *y;
+       for (int ii = 0; ii < 6; ii++) {
+               unsigned long int n;
+               if (ii != 0) {
+                       if (x[0] != ':') return 0; /* bad format */
+                       else x++;
+               }
+               n = strtoul (x, &y, 16);
+               x = y;
+               if (n > 0xFF) return 0; /* bad byte */
+               a.ether_addr_octet[ii] = n;
+       }
+       if (x[0] != 0) return 0; /* bad format */
+       *p_a = a;
+       return p_a;
+}
+
+struct ether_addr *ether_aton (const char *x)
+{
+       static struct ether_addr a;
+       return ether_aton_r (x, &a);
+}
+
+char *ether_ntoa_r (const struct ether_addr *p_a, char *x) {
+       char *y;
+       y = x;
+       for (int ii = 0; ii < 6; ii++) {
+               x += sprintf (x, ii == 0 ? "%.2X" : ":%.2X", p_a->ether_addr_octet[ii]);
+       }
+       return y;
+}
+
+char *ether_ntoa (const struct ether_addr *p_a) {
+       static char x[18];
+       return ether_ntoa_r (p_a, x);
+}