Switch the receive path to memory-mapped I/O with PACKET_RX_RING.
Change-Id: I93231de8f108db782eaa43aceb6cc5281d3739c4
diff --git a/clatd.c b/clatd.c
index e2c96e6..5cbcc1e 100644
--- a/clatd.c
+++ b/clatd.c
@@ -51,6 +51,7 @@
#include "getaddr.h"
#include "dump.h"
#include "tun.h"
+#include "ring.h"
#define DEVICENAME4 "clat4"
@@ -229,13 +230,10 @@
tunnel->write_fd6 = rawsock;
- int packetsock = socket(AF_PACKET, SOCK_DGRAM, htons(ETH_P_IPV6));
- if (packetsock < 0) {
- logmsg(ANDROID_LOG_FATAL, "packet socket failed: %s", strerror(errno));
+ tunnel->read_fd6 = ring_create(tunnel);
+ if (tunnel->read_fd6 < 0) {
exit(1);
}
-
- tunnel->read_fd6 = packetsock;
}
/* function: configure_interface
@@ -282,16 +280,16 @@
}
/* 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
- * tunnel - tun device data
+ * reads a packet from the tunnel fd and translates it
+ * read_fd - file descriptor to read original packet from
+ * write_fd - file descriptor to write translated packet to
+ * to_ipv6 - whether the packet is to be translated to ipv6 or ipv4
*/
-void read_packet(int active_fd, const struct tun_data *tunnel) {
+void read_packet(int read_fd, int write_fd, int to_ipv6) {
ssize_t readlen;
uint8_t buf[PACKETLEN], *packet;
- int fd;
- readlen = read(active_fd, buf, PACKETLEN);
+ readlen = read(read_fd, buf, PACKETLEN);
if(readlen < 0) {
logmsg(ANDROID_LOG_WARN,"read_packet/read error: %s", strerror(errno));
@@ -302,41 +300,32 @@
return;
}
- if (active_fd == tunnel->fd4) {
- ssize_t header_size = sizeof(struct tun_pi);
-
- if (readlen < header_size) {
- logmsg(ANDROID_LOG_WARN,"read_packet/short read: got %ld bytes", readlen);
- return;
- }
-
- struct tun_pi *tun_header = (struct tun_pi *) buf;
- uint16_t proto = ntohs(tun_header->proto);
- if (proto != ETH_P_IP) {
- logmsg(ANDROID_LOG_WARN, "%s: unknown packet type = 0x%x", __func__, proto);
- return;
- }
-
- if(tun_header->flags != 0) {
- logmsg(ANDROID_LOG_WARN, "%s: unexpected flags = %d", __func__, tun_header->flags);
- }
-
- fd = tunnel->write_fd6;
- packet = buf + header_size;
- readlen -= header_size;
- } else {
- fd = tunnel->fd4;
- packet = buf;
+ struct tun_pi *tun_header = (struct tun_pi *) buf;
+ if (readlen < (ssize_t) sizeof(*tun_header)) {
+ logmsg(ANDROID_LOG_WARN,"read_packet/short read: got %ld bytes", readlen);
+ return;
}
- translate_packet(fd, (fd == tunnel->write_fd6), packet, readlen);
+ uint16_t proto = ntohs(tun_header->proto);
+ if (proto != ETH_P_IP) {
+ logmsg(ANDROID_LOG_WARN, "%s: unknown packet type = 0x%x", __func__, proto);
+ return;
+ }
+
+ if(tun_header->flags != 0) {
+ logmsg(ANDROID_LOG_WARN, "%s: unexpected flags = %d", __func__, tun_header->flags);
+ }
+
+ packet = (uint8_t *) (tun_header + 1);
+ readlen -= sizeof(*tun_header);
+ translate_packet(write_fd, to_ipv6, packet, readlen);
}
/* function: event_loop
* reads packets from the tun network interface and passes them down the stack
* tunnel - tun device data
*/
-void event_loop(const struct tun_data *tunnel) {
+void event_loop(struct tun_data *tunnel) {
time_t last_interface_poll;
struct pollfd wait_fd[] = {
{ tunnel->read_fd6, POLLIN, 0 },
@@ -352,16 +341,16 @@
logmsg(ANDROID_LOG_WARN,"event_loop/poll returned an error: %s",strerror(errno));
}
} else {
- size_t i;
- for(i = 0; i < ARRAY_SIZE(wait_fd); i++) {
- // Call read_packet if the socket has data to be read, but also if an
- // error is waiting. If we don't call read() after getting POLLERR, a
- // subsequent poll() will return immediately with POLLERR again,
- // causing this code to spin in a loop. Calling read() will clear the
- // socket error flag instead.
- if(wait_fd[i].revents != 0) {
- read_packet(wait_fd[i].fd,tunnel);
- }
+ // Call read_packet if the socket has data to be read, but also if an
+ // error is waiting. If we don't call read() after getting POLLERR, a
+ // subsequent poll() will return immediately with POLLERR again,
+ // causing this code to spin in a loop. Calling read() will clear the
+ // socket error flag instead.
+ if (wait_fd[0].revents) {
+ ring_read(&tunnel->ring, tunnel->fd4, 0 /* to_ipv6 */);
+ }
+ if (wait_fd[1].revents) {
+ read_packet(tunnel->fd4, tunnel->write_fd6, 1 /* to_ipv6 */);
}
}