Use an empty server address for "older" firmwares.

[yaboot.git] / second / file.c

diff --git a/second/file.c b/second/file.c
index 5d5ccbdf10bd2df10b687fb2d5ae867025a74772..6b997b0589b0506155088d25d809eca41e02781b 100644 (file)
--- a/second/file.c
+++ b/second/file.c
@@ -51,6 +51,42 @@ ipv4_to_str(__u32 ip)
      return buf;
 }
 
+/* Ensure the string arg is a plausible IPv4 address */
+static char * is_valid_ipv4_str(char *str)
+{
+     int i;
+     long tmp;
+     __u32 ip = 0;
+     char *ptr=str, *endptr;
+
+     if (str == NULL)
+          return NULL;
+
+     for (i=0; i<4; i++, ptr = ++endptr) {
+          tmp = strtol(ptr, &endptr, 10);
+          if ((tmp & 0xff) != tmp)
+               return NULL;
+
+          /* If we reach the end of the string but we're not in the 4th octet
+           * we have an invalid IP */
+          if (*endptr == '\x0' && i!=3)
+               return NULL;
+
+          /* If we have anything other than a NULL or '.' we have an invlaid
+           * IP */
+          if (*endptr != '\x0' && *endptr != '.')
+               return NULL;
+
+          ip += (tmp << (24-(i*8)));
+     }
+
+     if (ip == 0 || ip == ~0u)
+          return NULL;
+
+     return str;
+}
+
+
 /*
  * Copy the string from source to dest till newline or comma(,) is seen
  * in the source.
@@ -130,10 +166,10 @@ extract_ipv4_args(char *imagepath, struct boot_fspec_t *result)
       * read the arguments in order: siaddr,filename,ciaddr,giaddr,
       * bootp-retries,tftp-retries,addl_prameters
       */
-     result->siaddr = scopy(&str, &args);
+     result->siaddr = is_valid_ipv4_str(scopy(&str, &args));
      result->file = scopy(&str, &args);
-     result->ciaddr = scopy(&str, &args);
-     result->giaddr = scopy(&str, &args);
+     result->ciaddr = is_valid_ipv4_str(scopy(&str, &args));
+     result->giaddr = is_valid_ipv4_str(scopy(&str, &args));
      result->bootp_retries = scopy(&str, &args);
      result->tftp_retries = scopy(&str, &args);
      if (*args) {
@@ -144,6 +180,78 @@ extract_ipv4_args(char *imagepath, struct boot_fspec_t *result)
      return 1;
 }
 
+/* DHCP options */
+enum dhcp_options {
+     DHCP_PAD = 0,
+     DHCP_NETMASK = 1,
+     DHCP_ROUTERS = 3,
+     DHCP_DNS = 6,
+     DHCP_END = 255,
+};
+
+#define DHCP_COOKIE        0x63825363
+#define DHCP_COOKIE_SIZE   4
+
+/*
+ * Process the bootp reply packet's vendor extensions.
+ * Vendor extensions are detailed in: http://www.faqs.org/rfcs/rfc1084.html
+ */
+static void
+extract_vendor_options(struct bootp_packet *packet, struct boot_fspec_t *result)
+{
+     int i = 0;
+     __u32 cookie;
+     __u8 *options = &packet->options[0];
+
+     memcpy(&cookie, &options[i], DHCP_COOKIE_SIZE);
+
+     if (cookie != DHCP_COOKIE) {
+          prom_printf("EEEK! cookie is fubar got %08x expected %08x\n",
+                      cookie, DHCP_COOKIE);
+          return;
+     }
+
+     i += DHCP_COOKIE_SIZE;
+
+     /* FIXME: It may be possible to run off the end of a packet here /if/
+      *         it's malformed. :( */
+     while (options[i] != DHCP_END) {
+          __u8 tag = options[i++], len;
+          __u32 value;
+
+          if (tag == DHCP_PAD)
+               continue;
+
+          len = options[i++];
+          memcpy(&value, &options[i], len);
+
+#if DEBUG
+{
+     DEBUG_F("tag=%2d, len=%2d, data=", tag, len);
+     int j;
+     for (j=0; j<len; j++)
+          prom_printf("%02x", options[i+j]);
+     prom_printf("\n");
+}
+#endif
+
+          switch (tag) {
+               case DHCP_NETMASK:
+                    /* FIXME: do we need to grok the subnet mask? */
+                    break;
+               case DHCP_ROUTERS:
+                    if ((result->giaddr == NULL || *(result->giaddr) == '\x0')
+                        && value != 0) {
+                         result->giaddr = ipv4_to_str(value);
+                         DEBUG_F("Storing %s as gateway from options\n",
+                                 result->giaddr);
+                    }
+                    break;
+               }
+          i += len;
+     }
+}
+
 /*
  * Check netinfo for ipv4 parameters and add them to the fspec iff the
  * fspec has no existing value.
@@ -170,16 +278,18 @@ extract_netinfo_args(struct boot_fspec_t *result)
      if (packet->ciaddr == 0 && packet->yiaddr != 0)
           packet->ciaddr = packet->yiaddr;
 
-     if ((result->siaddr == NULL || *(result->siaddr) == NULL)
+     if ((result->siaddr == NULL || *(result->siaddr) == '\x0')
          && packet->siaddr != 0)
           result->siaddr = ipv4_to_str(packet->siaddr);
-     if ((result->ciaddr == NULL || *(result->ciaddr) == NULL)
+     if ((result->ciaddr == NULL || *(result->ciaddr) == '\x0')
          && packet->ciaddr != 0)
           result->ciaddr = ipv4_to_str(packet->ciaddr);
-     if ((result->giaddr == NULL || *(result->giaddr) == NULL)
+     if ((result->giaddr == NULL || *(result->giaddr) == '\x0')
          && packet->giaddr != 0)
           result->giaddr = ipv4_to_str(packet->giaddr);
 
+     extract_vendor_options(packet, result);
+
      /* FIXME: Yck! if we /still/ do not have a gateway then "cheat" and use
       *        the server.  This will be okay if the client and server are on
       *        the same IP network, if not then lets hope the server does ICMP