[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/ipv6.c b/ap/app/clatd/ipv6.c
new file mode 100755
index 0000000..69063c4
--- /dev/null
+++ b/ap/app/clatd/ipv6.c
@@ -0,0 +1,190 @@
+/*
+ * 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.
+ *
+ * ipv6.c - takes ipv6 packets, finds their headers, and then calls translation functions on them
+ */
+#include <string.h>
+
+#include <arpa/inet.h>
+
+#include "translate.h"
+#include "checksum.h"
+#include "logging.h"
+#include "dump.h"
+#include "config.h"
+#include "debug.h"
+
+/* function: icmp6_packet
+ * takes an icmp6 packet and sets it up for translation
+ * out      - output packet
+ * icmp6    - pointer to icmp6 header in packet
+ * checksum - pseudo-header checksum (unused)
+ * len      - size of ip payload
+ * returns: the highest position in the output clat_packet that's filled in
+ */
+int icmp6_packet(clat_packet out, clat_packet_index pos, const struct icmp6_hdr *icmp6,
+                 uint32_t checksum, size_t len) {
+  const uint8_t *payload;
+  size_t payload_size;
+
+  if(len < sizeof(struct icmp6_hdr)) {
+    logmsg_dbg(ANDROID_LOG_ERROR, "icmp6_packet/(too small)");
+    return 0;
+  }
+
+  payload = (const uint8_t *) (icmp6 + 1);
+  payload_size = len - sizeof(struct icmp6_hdr);
+
+  return icmp6_to_icmp(out, pos, icmp6, checksum, payload, payload_size);
+}
+
+/* function: log_bad_address
+ * logs a bad address to android's log buffer if debugging is turned on
+ * fmt     - printf-style format, use %s to place the address
+ * badaddr - the bad address in question
+ */
+#if CLAT_DEBUG
+void log_bad_address(const char *fmt, const struct in6_addr *src, const struct in6_addr *dst) {
+  char srcstr[INET6_ADDRSTRLEN];
+  char dststr[INET6_ADDRSTRLEN];
+
+  inet_ntop(AF_INET6, src, srcstr, sizeof(srcstr));
+  inet_ntop(AF_INET6, dst, dststr, sizeof(dststr));
+  logmsg_dbg(ANDROID_LOG_ERROR, fmt, srcstr, dststr);
+}
+#else
+#define log_bad_address(fmt, src, dst)
+#endif
+
+/* function: ipv6_packet
+ * takes an ipv6 packet and hands it off to the layer 4 protocol function
+ * out    - output packet
+ * packet - packet data
+ * len    - size of packet
+ * returns: the highest position in the output clat_packet that's filled in
+ */
+int ipv6_packet(clat_packet out, clat_packet_index pos, const uint8_t *packet, size_t len, struct clat_icmp_frag *icmp_frag) {
+  const struct ip6_hdr *ip6 = (struct ip6_hdr *) packet;
+  struct iphdr *ip_targ = (struct iphdr *) out[pos].iov_base;
+  struct ip6_frag *frag_hdr = NULL;
+  uint8_t protocol;
+  const uint8_t *next_header;
+  size_t len_left;
+  uint32_t old_sum, new_sum;
+  int iov_len;
+
+  if(len < sizeof(struct ip6_hdr)) {
+    logmsg_dbg(ANDROID_LOG_ERROR, "ipv6_packet/too short for an ip6 header: %d", len);
+    return 0;
+  }
+
+  if(IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
+    log_bad_address("ipv6_packet/multicast %s->%s", &ip6->ip6_src, &ip6->ip6_dst);
+    return 0; // silently ignore
+  }
+
+  // If the packet is not from the plat subnet to the local subnet, or vice versa, drop it, unless
+  // it's an ICMP packet (which can come from anywhere). We do not send IPv6 packets from the plat
+  // subnet to the local subnet, but these can appear as inner packets in ICMP errors, so we need
+  // to translate them. We accept third-party ICMPv6 errors, even though their source addresses
+  // cannot be translated, so that things like unreachables and traceroute will work. fill_ip_header
+  // takes care of faking a source address for them.
+  if (!(is_in_plat_subnet(&ip6->ip6_src) &&
+        IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &Global_Clatd_Config.ipv6_local_subnet)) &&
+      !(is_in_plat_subnet(&ip6->ip6_dst) &&
+        IN6_ARE_ADDR_EQUAL(&ip6->ip6_src, &Global_Clatd_Config.ipv6_local_subnet)) &&
+      ip6->ip6_nxt != IPPROTO_ICMPV6) {
+    log_bad_address("ipv6_packet/wrong source address: %s->%s", &ip6->ip6_src, &ip6->ip6_dst);
+    return 0;
+  }
+
+  next_header = packet + sizeof(struct ip6_hdr);
+  len_left = len - sizeof(struct ip6_hdr);
+
+  protocol = ip6->ip6_nxt;
+
+  /* Fill in the IPv4 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_ip_header(ip_targ, 0, protocol, ip6);
+  out[pos].iov_len = sizeof(struct iphdr);
+
+  // If there's a Fragment header, parse it and decide what the next header is.
+  // Do this before calculating the pseudo-header checksum because it updates the next header value.
+  if (protocol == IPPROTO_FRAGMENT) {
+    frag_hdr = (struct ip6_frag *) next_header;
+    if (len_left < sizeof(*frag_hdr)) {
+      logmsg_dbg(ANDROID_LOG_ERROR, "ipv6_packet/too short for fragment header: %d", len);
+      return 0;
+    }
+
+    next_header += sizeof(*frag_hdr);
+    len_left -= sizeof(*frag_hdr);
+
+    protocol = parse_frag_header(frag_hdr, ip_targ);
+  }
+  old_sum = ipv6_pseudo_header_checksum(ip6, len_left, protocol);
+  // ICMP and ICMPv6 have different protocol numbers.
+  if (protocol == IPPROTO_ICMPV6) {
+    protocol = IPPROTO_ICMP;
+    ip_targ->protocol = IPPROTO_ICMP;
+  }
+
+  /* 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.
+   */
+
+  new_sum = ipv4_pseudo_header_checksum(ip_targ, len_left);
+
+  // Does not support IPv6 extension headers except Fragment.
+  if (frag_hdr && (frag_hdr->ip6f_offlg & IP6F_OFF_MASK)) {
+	uint16_t frag_len = ntohs(frag_hdr->ip6f_offlg & IP6F_OFF_MASK);
+	if(icmp_frag && frag_len > 0 && (protocol == IPPROTO_ICMP)){
+		icmp_frag->ip_len = len_left + frag_len;
+		icmp_frag->ip_id = htons(ntohl(frag_hdr->ip6f_ident) & 0xffff);
+		icmp_frag->flag = 2;
+	}
+    iov_len = generic_packet(out, pos + 2, next_header, len_left);
+  } else if (protocol == IPPROTO_ICMP) {
+	if(icmp_frag && frag_hdr){
+		icmp_frag->ip_len = len_left;
+		icmp_frag->ip_id = htons(ntohl(frag_hdr->ip6f_ident) & 0xffff);
+		icmp_frag->flag = 1;
+	}
+    iov_len = icmp6_packet(out, pos + 2, (const struct icmp6_hdr *) next_header, old_sum, len_left);
+  } else if (protocol == IPPROTO_TCP) {
+    iov_len = tcp_packet(out, pos + 2, (const struct tcphdr *) next_header, old_sum, new_sum,
+                         len_left);
+  } else if (protocol == IPPROTO_UDP) {
+    iov_len = udp_packet(out, pos + 2, (const struct udphdr *) next_header, old_sum, new_sum,
+                         len_left);
+  } else if (protocol == IPPROTO_GRE) {
+    iov_len = generic_packet(out, pos + 2, next_header, len_left);
+  } else {
+#if CLAT_DEBUG
+    logmsg(ANDROID_LOG_ERROR, "ipv6_packet/unknown next header type: %x", ip6->ip6_nxt);
+    logcat_hexdump("ipv6/nxthdr", packet, len);
+#endif
+    return 0;
+  }
+
+  // Set the length and calculate the checksum.
+  ip_targ->tot_len = htons(ntohs(ip_targ->tot_len) + packet_length(out, pos));
+  ip_targ->check = ip_checksum(ip_targ, sizeof(struct iphdr));
+  return iov_len;
+}