Only update resolv.conf if changed (avoid logspam)

[project/netifd.git] / utils.c

diff --git a/utils.c b/utils.c
index 65109d7..6b53c22 100644 (file)
--- a/utils.c
+++ b/utils.c
@@ -15,6 +15,9 @@
 #include <stdlib.h>
 #include "utils.h"
 
+#include <arpa/inet.h>
+#include <netinet/in.h>
+
 void
 __vlist_simple_init(struct vlist_simple_tree *tree, int offset)
 {
@@ -66,3 +69,102 @@ vlist_simple_flush_all(struct vlist_simple_tree *tree)
        tree->version = -1;
        vlist_simple_flush(tree);
 }
+
+unsigned int
+parse_netmask_string(const char *str, bool v6)
+{
+       struct in_addr addr;
+       unsigned int ret;
+       char *err = NULL;
+
+       if (!strchr(str, '.')) {
+               ret = strtoul(str, &err, 0);
+               if (err && *err)
+                       goto error;
+
+               return ret;
+       }
+
+       if (v6)
+               goto error;
+
+       if (inet_aton(str, &addr) != 1)
+               goto error;
+
+       return 32 - fls(~(ntohl(addr.s_addr)));
+
+error:
+       return ~0;
+}
+
+bool
+split_netmask(char *str, unsigned int *netmask, bool v6)
+{
+       char *delim = strchr(str, '/');
+
+       if (delim) {
+               *(delim++) = 0;
+
+               *netmask = parse_netmask_string(delim, v6);
+       }
+       return true;
+}
+
+int
+parse_ip_and_netmask(int af, const char *str, void *addr, unsigned int *netmask)
+{
+       char *astr = alloca(strlen(str) + 1);
+
+       strcpy(astr, str);
+       if (!split_netmask(astr, netmask, af == AF_INET6))
+               return 0;
+
+       if (af == AF_INET6) {
+               if (*netmask > 128)
+                       return 0;
+       } else {
+               if (*netmask > 32)
+                       return 0;
+       }
+
+       return inet_pton(af, astr, addr);
+}
+
+char *
+format_macaddr(uint8_t *mac)
+{
+       static char str[sizeof("ff:ff:ff:ff:ff:ff ")];
+
+       snprintf(str, sizeof(str), "%02x:%02x:%02x:%02x:%02x:%02x",
+                mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
+
+       return str;
+}
+
+uint32_t
+crc32_file(FILE *fp)
+{
+       static uint32_t *crcvals = NULL;
+       if (!crcvals) {
+               crcvals = malloc(sizeof(*crcvals) * 256);
+
+               for (size_t i = 0; i < 256; ++i) {
+                       uint32_t c = i;
+                       for (size_t j = 0; j < 8; ++j)
+                               c = (c & 1) ? (0xEDB88320 ^ (c >> 1)) : (c >> 1);
+                       crcvals[i] = c;
+               }
+       }
+
+       uint8_t buf[1024];
+       size_t len;
+       uint32_t c = 0xFFFFFFFF;
+
+       do {
+               len = fread(buf, 1, sizeof(buf), fp);
+               for (size_t i = 0; i < len; ++i)
+                       c = crcvals[(c ^ buf[i]) & 0xFF] ^ (c >> 8);
+       } while (len == sizeof(buf));
+
+       return c ^ 0xFFFFFFFF;
+}