[Feature][ZXW-237]merge P54U03 version

Only Configure: No
Affected branch: master
Affected module: unknow
Is it affected on both ZXIC and MTK: only ZXIC
Self-test: Yes
Doc Update: No

Change-Id: Id39ef8b992af691eab09c01d4ea26da89e5f4049
diff --git a/ap/app/clatd/ipv4.c b/ap/app/clatd/ipv4.c
new file mode 100755
index 0000000..406cc42
--- /dev/null
+++ b/ap/app/clatd/ipv4.c
@@ -0,0 +1,157 @@
+/*
+ * Copyright 2011 Daniel Drown
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * ipv4.c - takes ipv4 packets, finds their headers, and then calls translation functions on them
+ */
+#include <string.h>
+
+#include "translate.h"
+#include "checksum.h"
+#include "logging.h"
+#include "debug.h"
+#include "dump.h"
+
+/* function: icmp_packet
+ * translates an icmp packet
+ * out      - output packet
+ * icmp     - pointer to icmp header in packet
+ * checksum - pseudo-header checksum
+ * len      - size of ip payload
+ * returns: the highest position in the output clat_packet that's filled in
+ */
+int icmp_packet(clat_packet out, clat_packet_index pos, const struct icmphdr *icmp,
+                uint32_t checksum, size_t len) {
+  const uint8_t *payload;
+  size_t payload_size;
+
+  if(len < sizeof(struct icmphdr)) {
+    logmsg_dbg(ANDROID_LOG_ERROR, "icmp_packet/(too small)");
+    return 0;
+  }
+
+  payload = (const uint8_t *) (icmp + 1);
+  payload_size = len - sizeof(struct icmphdr);
+
+  return icmp_to_icmp6(out, pos, icmp, checksum, payload, payload_size);
+}
+
+/* function: ipv4_packet
+ * translates an ipv4 packet
+ * out    - output packet
+ * packet - packet data
+ * len    - size of packet
+ * returns: the highest position in the output clat_packet that's filled in
+ */
+int ipv4_packet(clat_packet out, clat_packet_index pos, const uint8_t *packet, size_t len, struct clat_icmp_frag *icmp_frag) {
+  const struct iphdr *header = (struct iphdr *) packet;
+  struct ip6_hdr *ip6_targ = (struct ip6_hdr *) out[pos].iov_base;
+  struct ip6_frag *frag_hdr;
+  size_t frag_hdr_len;
+  uint8_t nxthdr;
+  const uint8_t *next_header;
+  size_t len_left;
+  uint32_t old_sum, new_sum;
+  int iov_len;
+
+  if(len < sizeof(struct iphdr)) {
+    logmsg_dbg(ANDROID_LOG_ERROR, "ip_packet/too short for an ip header");
+    return 0;
+  }
+
+  if(header->ihl < 5) {
+    logmsg_dbg(ANDROID_LOG_ERROR, "ip_packet/ip header length set to less than 5: %x", header->ihl);
+    return 0;
+  }
+
+  if((size_t) header->ihl * 4 > len) { // ip header length larger than entire packet
+    logmsg_dbg(ANDROID_LOG_ERROR, "ip_packet/ip header length set too large: %x", header->ihl);
+    return 0;
+  }
+
+  if(header->version != 4) {
+    logmsg_dbg(ANDROID_LOG_ERROR, "ip_packet/ip header version not 4: %x", header->version);
+    return 0;
+  }
+
+  /* rfc6145 - If any IPv4 options are present in the IPv4 packet, they MUST be
+   * ignored and the packet translated normally; there is no attempt to
+   * translate the options.
+   */
+
+  next_header = packet + header->ihl*4;
+  len_left = len - header->ihl * 4;
+
+  nxthdr = header->protocol;
+  if (nxthdr == IPPROTO_ICMP) {
+    // ICMP and ICMPv6 have different protocol numbers.
+    nxthdr = IPPROTO_ICMPV6;
+  }
+
+  /* Fill in the IPv6 header. We need to do this before we translate the packet because TCP and
+   * UDP include parts of the IP header in the checksum. Set the length to zero because we don't
+   * know it yet.
+   */
+  fill_ip6_header(ip6_targ, 0, nxthdr, header);
+  out[pos].iov_len = sizeof(struct ip6_hdr);
+
+  /* Calculate the pseudo-header checksum.
+   * Technically, the length that is used in the pseudo-header checksum is the transport layer
+   * length, which is not the same as len_left in the case of fragmented packets. But since
+   * translation does not change the transport layer length, the checksum is unaffected.
+   */
+  old_sum = ipv4_pseudo_header_checksum(header, len_left);
+  new_sum = ipv6_pseudo_header_checksum(ip6_targ, len_left, nxthdr);
+
+  // If the IPv4 packet is fragmented, add a Fragment header.
+  frag_hdr = (struct ip6_frag *) out[pos + 1].iov_base;
+  frag_hdr_len = maybe_fill_frag_header(frag_hdr, ip6_targ, header);
+  out[pos + 1].iov_len = frag_hdr_len;
+
+  if (frag_hdr_len && frag_hdr->ip6f_offlg & IP6F_OFF_MASK) {
+	uint16_t frag_len = ((ntohs(header->frag_off))&IP_OFFMASK)<< 3;
+	if(icmp_frag && frag_len > 0 && ((ntohs(header->frag_off)) & IP_MF) == 0 && (nxthdr == IPPROTO_ICMPV6)){
+		icmp_frag->ip_len = len_left + frag_len;
+		icmp_frag->ip_id = header->id;
+		icmp_frag->flag = 2;
+	}
+    // Non-first fragment. Copy the rest of the packet as is.
+    iov_len = generic_packet(out, pos + 2, next_header, len_left);
+  } else if (nxthdr == IPPROTO_ICMPV6) {
+	if(icmp_frag && ((ntohs(header->frag_off)) & (IP_MF|IP_OFFMASK)) == IP_MF){
+		icmp_frag->ip_len = len_left;
+		icmp_frag->ip_id = header->id;
+		icmp_frag->flag = 1;
+	}
+    iov_len = icmp_packet(out, pos + 2, (const struct icmphdr *) next_header, new_sum, len_left);
+  } else if (nxthdr == IPPROTO_TCP) {
+    iov_len = tcp_packet(out, pos + 2, (const struct tcphdr *) next_header, old_sum, new_sum,
+                         len_left);
+  } else if (nxthdr == IPPROTO_UDP) {
+    iov_len = udp_packet(out, pos + 2, (const struct udphdr *) next_header, old_sum, new_sum,
+                         len_left);
+  } else if (nxthdr == IPPROTO_GRE) {
+    iov_len = generic_packet(out, pos + 2, next_header, len_left);
+  } else {
+#if CLAT_DEBUG
+    logmsg_dbg(ANDROID_LOG_ERROR, "ip_packet/unknown protocol: %x",header->protocol);
+    logcat_hexdump("ipv4/protocol", packet, len);
+#endif
+    return 0;
+  }
+
+  // Set the length.
+  ip6_targ->ip6_plen = htons(packet_length(out, pos));
+  return iov_len;
+}