1 files changed, 112 insertions, 0 deletions
diff --git a/grub-core/net/icmp.c b/grub-core/net/icmp.c
new file mode 100644
index 0000000..b1eef11
--- /dev/null
+++ b/grub-core/net/icmp.c
@@ -0,0 +1,112 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2010,2011  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/net.h>
+#include <grub/net/ip.h>
+#include <grub/net/netbuff.h>
+
+struct icmp_header
+{
+  grub_uint8_t type;
+  grub_uint8_t code;
+  grub_uint16_t checksum;
+} GRUB_PACKED;
+
+struct ping_header
+{
+  grub_uint16_t id;
+  grub_uint16_t seq;
+} GRUB_PACKED;
+
+enum
+  {
+    ICMP_ECHO_REPLY = 0,
+    ICMP_ECHO = 8,
+  };
+
+grub_err_t
+grub_net_recv_icmp_packet (struct grub_net_buff *nb,
+			   struct grub_net_network_level_interface *inf,
+			   const grub_net_link_level_address_t *ll_src,
+			   const grub_net_network_level_address_t *src)
+{
+  struct icmp_header *icmph;
+  grub_err_t err;
+  grub_uint16_t checksum;
+
+  /* Ignore broadcast.  */
+  if (!inf)
+    {
+      grub_netbuff_free (nb);
+      return GRUB_ERR_NONE;
+    }
+
+  icmph = (struct icmp_header *) nb->data;
+
+  if (nb->tail - nb->data < (grub_ssize_t) sizeof (*icmph))
+    {
+      grub_netbuff_free (nb);
+      return GRUB_ERR_NONE;
+    }
+
+  checksum = icmph->checksum;
+  icmph->checksum = 0;
+  if (checksum != grub_net_ip_chksum (nb->data, nb->tail - nb->data))
+    {
+      icmph->checksum = checksum;
+      return GRUB_ERR_NONE;
+    }
+  icmph->checksum = checksum;
+
+  err = grub_netbuff_pull (nb, sizeof (*icmph));
+  if (err)
+    return err;
+
+  switch (icmph->type)
+    {
+    case ICMP_ECHO:
+      {
+	struct grub_net_buff *nb_reply;
+	struct icmp_header *icmphr;
+	if (icmph->code)
+	  break;
+	nb_reply = grub_netbuff_make_pkt (nb->tail - nb->data + sizeof (*icmphr));
+	if (!nb_reply)
+	  {
+	    grub_netbuff_free (nb);
+	    return grub_errno;
+	  }
+	grub_memcpy (nb_reply->data + sizeof (*icmphr), nb->data, nb->tail - nb->data);
+	icmphr = (struct icmp_header *) nb_reply->data;
+	icmphr->type = ICMP_ECHO_REPLY;
+	icmphr->code = 0;
+	icmphr->checksum = 0;
+	icmphr->checksum = grub_net_ip_chksum ((void *) nb_reply->data,
+					       nb_reply->tail - nb_reply->data);
+	err = grub_net_send_ip_packet (inf, src, ll_src,
+				       nb_reply, GRUB_NET_IP_ICMP);
+
+	grub_netbuff_free (nb);
+	grub_netbuff_free (nb_reply);
+	return err;
+      }
+    };
+
+  grub_netbuff_free (nb);
+  return GRUB_ERR_NONE;
+}