DO NOT MERGE: Move translation entry point into translate.c.

The entry point to the translation code is currently called
packet_handler and lives in clatd.c. Move it into translate.c
and rename it to translate_packet, since that's what it does.

Also get rid of some redundant includes.

Bug: 11542311
Change-Id: I8529fb87f3a86ee6724fad54787c33a5e86c56ab

6 files changed, 73 insertions, 91 deletions

diff --git a/clatd.c b/clatd.c
index a0ee07d..3ab2371 100644
--- a/clatd.c
+++ b/clatd.c
@@ -29,15 +29,6 @@
 #include <arpa/inet.h>
 #include <fcntl.h>
 
-#include <netinet/in.h>
-#include <netinet/ip.h>
-#include <netinet/ip_icmp.h>
-#include <netinet/udp.h>
-#include <netinet/tcp.h>
-#include <netinet/ip6.h>
-#include <netinet/icmp6.h>
-#include <linux/icmp.h>
-
 #include <sys/capability.h>
 #include <sys/uio.h>
 #include <linux/prctl.h>
@@ -63,11 +54,6 @@
 int forwarding_fd = -1;
 volatile sig_atomic_t running = 1;
 
-struct tun_data {
-  char device6[IFNAMSIZ], device4[IFNAMSIZ];
-  int fd6, fd4;
-};
-
 /* function: set_forwarding
  * enables/disables ipv6 forwarding
  */
@@ -305,56 +291,6 @@ void configure_interface(const char *uplink_interface, const char *plat_prefix,
   configure_tun_ip(tunnel);
 }
 
-/* function: packet_handler
- * takes a tun header and a packet and sends it down the stack
- * tunnel     - tun device data
- * tun_header - tun header
- * packet     - packet
- * packetsize - size of packet
- */
-void packet_handler(const struct tun_data *tunnel, struct tun_pi *tun_header, const char *packet,
-                    size_t packetsize) {
-  int fd;
-  int iov_len = 0;
-
-  // Allocate buffers for all packet headers.
-  struct tun_pi tun_targ;
-  char iphdr[sizeof(struct ip6_hdr)];
-  char transporthdr[MAX_TCP_HDR];
-  char icmp_iphdr[sizeof(struct ip6_hdr)];
-  char icmp_transporthdr[MAX_TCP_HDR];
-
-  // iovec of the packets we'll send. This gets passed down to the translation functions.
-  clat_packet out = {
-    { &tun_targ, sizeof(tun_targ) },  // Tunnel header.
-    { iphdr, 0 },                     // IP header.
-    { transporthdr, 0 },              // Transport layer header.
-    { icmp_iphdr, 0 },                // ICMP error inner IP header.
-    { icmp_transporthdr, 0 },         // ICMP error transport layer header.
-    { NULL, 0 },                      // Payload. No buffer, it's a pointer to the original payload.
-  };
-
-  if(tun_header->flags != 0) {
-    logmsg(ANDROID_LOG_WARN,"packet_handler: unexpected flags = %d", tun_header->flags);
-  }
-
-  if(ntohs(tun_header->proto) == ETH_P_IP) {
-    fd = tunnel->fd6;
-    fill_tun_header(&tun_targ, ETH_P_IPV6);
-    iov_len = ipv4_packet(out, CLAT_POS_IPHDR, packet, packetsize);
-  } else if(ntohs(tun_header->proto) == ETH_P_IPV6) {
-    fd = tunnel->fd4;
-    fill_tun_header(&tun_targ, ETH_P_IP);
-    iov_len = ipv6_packet(out, CLAT_POS_IPHDR, packet, packetsize);
-  } else {
-    logmsg(ANDROID_LOG_WARN,"packet_handler: unknown packet type = %x",tun_header->proto);
-  }
-
-  if (iov_len > 0) {
-    writev(fd, out, iov_len);
-  }
-}
-
 /* function: read_packet
  * reads a packet from the tunnel fd and passes it down the stack
  * active_fd - tun file descriptor marked ready for reading
@@ -383,7 +319,7 @@ void read_packet(int active_fd, const struct tun_data *tunnel) {
       return;
     }
 
-    packet_handler(tunnel, (struct tun_pi *) packet, packet + header_size, readlen - header_size);
+    translate_packet(tunnel, (struct tun_pi *) packet, packet + header_size, readlen - header_size);
   }
 }
 
diff --git a/clatd.h b/clatd.h
index 3459b09..44a655e 100644
--- a/clatd.h
+++ b/clatd.h
@@ -18,6 +18,7 @@
 #ifndef __CLATD_H__
 #define __CLATD_H__
 
+#include <linux/if.h>
 #include <linux/if_tun.h>
 
 #define MAXMTU 1500
@@ -30,4 +31,9 @@
 // how frequently (in seconds) to poll for an address change while there is no traffic
 #define NO_TRAFFIC_INTERFACE_POLL_FREQUENCY 90
 
+struct tun_data {
+  char device6[IFNAMSIZ], device4[IFNAMSIZ];
+  int fd6, fd4;
+};
+
 #endif /* __CLATD_H__ */
diff --git a/ipv4.c b/ipv4.c
index 1d5b0b2..c828ffa 100644
--- a/ipv4.c
+++ b/ipv4.c
@@ -17,15 +17,6 @@
  */
 #include <string.h>
 
-#include <netinet/in.h>
-#include <netinet/ip.h>
-#include <netinet/ip_icmp.h>
-#include <netinet/udp.h>
-#include <netinet/tcp.h>
-#include <netinet/ip6.h>
-#include <netinet/icmp6.h>
-#include <linux/icmp.h>
-
 #include "translate.h"
 #include "checksum.h"
 #include "logging.h"
diff --git a/ipv6.c b/ipv6.c
index e4a73fe..371d9e1 100644
--- a/ipv6.c
+++ b/ipv6.c
@@ -17,14 +17,6 @@
  */
 #include <string.h>
 
-#include <netinet/in.h>
-#include <netinet/ip.h>
-#include <netinet/ip_icmp.h>
-#include <netinet/udp.h>
-#include <netinet/tcp.h>
-#include <netinet/ip6.h>
-#include <netinet/icmp6.h>
-#include <linux/icmp.h>
 #include <arpa/inet.h>
 
 #include "translate.h"
diff --git a/translate.c b/translate.c
index 9a0f1b5..f7f09cb 100644
--- a/translate.c
+++ b/translate.c
@@ -16,15 +16,7 @@
  * translate.c - CLAT functions / partial implementation of rfc6145
  */
 #include <string.h>
-
-#include <netinet/in.h>
-#include <netinet/ip.h>
-#include <netinet/ip_icmp.h>
-#include <netinet/udp.h>
-#include <netinet/tcp.h>
-#include <netinet/ip6.h>
-#include <netinet/icmp6.h>
-#include <linux/icmp.h>
+#include <sys/uio.h>
 
 #include "icmp.h"
 #include "translate.h"
@@ -175,6 +167,7 @@ void fill_ip6_header(struct ip6_hdr *ip6, uint16_t payload_len, uint8_t protocol
   ip6->ip6_dst = ipv4_addr_to_ipv6_addr(old_header->daddr);
 }
 
+
 /* function: icmp_to_icmp6
  * translate ipv4 icmp to ipv6 icmp
  * out          - output packet
@@ -426,3 +419,53 @@ int tcp_translate(clat_packet out, int pos, const struct tcphdr *tcp, size_t hea
 
   return CLAT_POS_PAYLOAD + 1;
 }
+
+/* function: translate_packet
+ * takes a tun header and a packet and sends it down the stack
+ * tunnel     - tun device data
+ * tun_header - tun header
+ * packet     - packet
+ * packetsize - size of packet
+ */
+void translate_packet(const struct tun_data *tunnel, struct tun_pi *tun_header, const char *packet,
+                      size_t packetsize) {
+  int fd;
+  int iov_len = 0;
+
+  // Allocate buffers for all packet headers.
+  struct tun_pi tun_targ;
+  char iphdr[sizeof(struct ip6_hdr)];
+  char transporthdr[MAX_TCP_HDR];
+  char icmp_iphdr[sizeof(struct ip6_hdr)];
+  char icmp_transporthdr[MAX_TCP_HDR];
+
+  // iovec of the packets we'll send. This gets passed down to the translation functions.
+  clat_packet out = {
+    { &tun_targ, sizeof(tun_targ) },  // Tunnel header.
+    { iphdr, 0 },                     // IP header.
+    { transporthdr, 0 },              // Transport layer header.
+    { icmp_iphdr, 0 },                // ICMP error inner IP header.
+    { icmp_transporthdr, 0 },         // ICMP error transport layer header.
+    { NULL, 0 },                      // Payload. No buffer, it's a pointer to the original payload.
+  };
+
+  if(tun_header->flags != 0) {
+    logmsg(ANDROID_LOG_WARN, "translate_packet: unexpected flags = %d", tun_header->flags);
+  }
+
+  if(ntohs(tun_header->proto) == ETH_P_IP) {
+    fd = tunnel->fd6;
+    fill_tun_header(&tun_targ, ETH_P_IPV6);
+    iov_len = ipv4_packet(out, CLAT_POS_IPHDR, packet, packetsize);
+  } else if(ntohs(tun_header->proto) == ETH_P_IPV6) {
+    fd = tunnel->fd4;
+    fill_tun_header(&tun_targ, ETH_P_IP);
+    iov_len = ipv6_packet(out, CLAT_POS_IPHDR, packet, packetsize);
+  } else {
+    logmsg(ANDROID_LOG_WARN, "translate_packet: unknown packet type = %x",tun_header->proto);
+  }
+
+  if (iov_len > 0) {
+    writev(fd, out, iov_len);
+  }
+}
diff --git a/translate.h b/translate.h
index cfb7bbb..3378254 100644
--- a/translate.h
+++ b/translate.h
@@ -18,8 +18,18 @@
 #ifndef __TRANSLATE_H__
 #define __TRANSLATE_H__
 
+#include <netinet/in.h>
+#include <netinet/ip.h>
+#include <netinet/ip_icmp.h>
+#include <netinet/udp.h>
+#include <netinet/tcp.h>
+#include <netinet/ip6.h>
+#include <netinet/icmp6.h>
+#include <linux/icmp.h>
 #include <linux/if_tun.h>
 
+#include "clatd.h"
+
 #define MAX_TCP_HDR (15 * 4)   // Data offset field is 4 bits and counts in 32-bit words.
 
 // A clat_packet is an array of iovec structures representing a packet that we are translating.
@@ -47,6 +57,10 @@ void fill_ip_header(struct iphdr *ip_targ, uint16_t payload_len, uint8_t protoco
 void fill_ip6_header(struct ip6_hdr *ip6, uint16_t payload_len, uint8_t protocol,
                      const struct iphdr *old_header);
 
+// Translate and send packets.
+void translate_packet(const struct tun_data *tunnel, struct tun_pi *tun_header, const char *packet,
+                      size_t packetsize);
+
 // Translate IPv4 and IPv6 packets.
 int ipv4_packet(clat_packet out, int pos, const char *packet, size_t len);
 int ipv6_packet(clat_packet out, int pos, const char *packet, size_t len);