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udp: Introduce recvmmsg()/sendmmsg(), zero-copy path from socket

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Packets are received directly onto pre-cooked, static buffers
for IPv4 (with partial checksum pre-calculation) and IPv6 frames,
with pre-filled Ethernet addresses and, partially, IP headers,
and sent out from the same buffers with sendmmsg(), for both
passt and pasta (non-local traffic only) modes.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
Stefano Brivio 2021-07-21 12:01:04 +02:00
parent 7fa3e90290
commit 64a0ba3b27
9 changed files with 537 additions and 61 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
passt.c
View File

@ -409,6 +409,18 @@ static void timer_handler(struct ctx *c, struct timespec *now)
}
}
/**
* proto_update_l2_buf() - Update scatter-gather L2 buffers in protocol handlers
* @eth_d: Ethernet destination address, NULL if unchanged
* @eth_s: Ethernet source address, NULL if unchanged
* @ip_da: Pointer to IPv4 destination address, NULL if unchanged
*/
void proto_update_l2_buf(unsigned char *eth_d, unsigned char *eth_s,
uint32_t *ip_da)
{
udp_update_l2_buf(eth_d, eth_s, ip_da);
}
/**
* usage_passt() - Print usage for "passt" mode and exit
* @name: Executable name
@ -499,6 +511,8 @@ int main(int argc, char **argv)
get_dns(&c);
get_bound_ports(&c);
proto_update_l2_buf(c.mac_guest, c.mac, &c.addr4);
if (udp_sock_init(&c) || tcp_sock_init(&c))
exit(EXIT_FAILURE);

3
passt.h
View File

@ -134,3 +134,6 @@ struct ctx {
struct udp_ctx udp;
struct icmp_ctx icmp;
};
void proto_update_l2_buf(unsigned char *eth_d, unsigned char *eth_s,
uint32_t *ip_da);

82
pcap.c
View File

@ -12,10 +12,12 @@
* Author: Stefano Brivio <sbrivio@redhat.com>
*/
#define _GNU_SOURCE
#include <stdio.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/stat.h>
@ -90,6 +92,65 @@ void pcap(char *pkt, size_t len)
write(pcap_fd, pkt, len);
}
/**
* pcapm() - Capture multiple frames from message header to pcap file
* @mh: Pointer to sendmsg() message header buffer
*/
void pcapm(struct msghdr *mh)
{
struct pcap_pkthdr h;
struct timeval tv;
unsigned int i;
if (pcap_fd == -1)
return;
gettimeofday(&tv, NULL);
h.tv_sec = tv.tv_sec;
h.tv_usec = tv.tv_usec;
for (i = 0; i < mh->msg_iovlen; i++) {
struct iovec *iov = &mh->msg_iov[i];
h.caplen = h.len = iov->iov_len - 4;
write(pcap_fd, &h, sizeof(h));
write(pcap_fd, (char *)iov->iov_base + 4, iov->iov_len - 4);
}
}
/**
* pcapm() - Capture multiple frames from multiple message headers to pcap file
* @mmh: Pointer to first sendmmsg() header
*/
void pcapmm(struct mmsghdr *mmh, unsigned int vlen)
{
struct pcap_pkthdr h;
struct timeval tv;
unsigned int i, j;
if (pcap_fd == -1)
return;
gettimeofday(&tv, NULL);
h.tv_sec = tv.tv_sec;
h.tv_usec = tv.tv_usec;
for (i = 0; i < vlen; i++) {
struct msghdr *mh = &mmh[i].msg_hdr;
for (j = 0; j < mh->msg_iovlen; j++) {
struct iovec *iov = &mh->msg_iov[j];
h.caplen = h.len = iov->iov_len - 4;
write(pcap_fd, &h, sizeof(h));
write(pcap_fd, (char *)iov->iov_base + 4,
iov->iov_len - 4);
}
}
}
/**
* pcap_init() - Initialise pcap file
* @c: Execution context
@ -129,10 +190,27 @@ void pcap_init(struct ctx *c, int index)
}
#else /* DEBUG */
void pcap(char *pkt, size_t len) {
void pcap(char *pkt, size_t len)
{
(void)pkt;
(void)len;
}
void pcap_init(void) { }
void pcapm(struct msghdr *mh)
{
(void)mh;
}
void pcapmm(struct mmsghdr *mmh, unsigned int vlen)
{
(void)mmh;
(void)vlen;
}
void pcap_init(struct ctx *c, int sock_index)
{
(void)c;
(void)sock_index;
}
#endif

2
pcap.h
View File

@ -1,2 +1,4 @@
void pcap(char *pkt, size_t len);
void pcapm(struct msghdr *mh);
void pcapmm(struct mmsghdr *mmh, unsigned int vlen);
void pcap_init(struct ctx *c, int sock_index);

23
tap.c
View File

@ -219,7 +219,10 @@ static int tap4_handler(struct ctx *c, struct tap_msg *msg, size_t count,
iph = (struct iphdr *)(eh + 1);
l4h = (char *)iph + iph->ihl * 4;
c->addr4_seen = iph->saddr;
if (c->addr4_seen != iph->saddr) {
c->addr4_seen = iph->saddr;
proto_update_l2_buf(NULL, NULL, &c->addr4_seen);
}
msg[i].l4h = l4h;
msg[i].l4_len = len - ((intptr_t)l4h - (intptr_t)eh);
@ -332,10 +335,14 @@ static int tap6_handler(struct ctx *c, struct tap_msg *msg, size_t count,
msg[i].l4h = l4h;
msg[i].l4_len = len - ((intptr_t)l4h - (intptr_t)eh);
if (IN6_IS_ADDR_LINKLOCAL(&ip6h->saddr))
if (IN6_IS_ADDR_LINKLOCAL(&ip6h->saddr)) {
c->addr6_ll_seen = ip6h->saddr;
else
if (IN6_IS_ADDR_UNSPECIFIED(&c->addr6_seen))
c->addr6_seen = ip6h->saddr;
} else {
c->addr6_seen = ip6h->saddr;
}
ip6h->saddr = c->addr6;
@ -458,7 +465,10 @@ static int tap_handler_passt(struct ctx *c, struct timespec *now)
while (i < msg_count) {
eh = (struct ethhdr *)msg[i].start;
memcpy(c->mac_guest, eh->h_source, ETH_ALEN);
if (memcmp(c->mac_guest, eh->h_source, ETH_ALEN)) {
memcpy(c->mac_guest, eh->h_source, ETH_ALEN);
proto_update_l2_buf(c->mac_guest, NULL, NULL);
}
switch (ntohs(eh->h_proto)) {
case ETH_P_ARP:
@ -516,7 +526,10 @@ static int tap_handler_pasta(struct ctx *c, struct timespec *now)
pcap(msg.start, msg.len);
memcpy(c->mac_guest, eh->h_source, ETH_ALEN);
if (memcmp(c->mac_guest, eh->h_source, ETH_ALEN)) {
memcpy(c->mac_guest, eh->h_source, ETH_ALEN);
proto_update_l2_buf(c->mac_guest, NULL, NULL);
}
switch (ntohs(eh->h_proto)) {
case ETH_P_ARP:

373
udp.c
View File

@ -113,9 +113,11 @@
#include "util.h"
#include "passt.h"
#include "tap.h"
#include "pcap.h"
#define UDP_CONN_TIMEOUT 180 /* s, timeout for ephemeral or local bind */
#define UDP_SPLICE_FRAMES 128
#define UDP_TAP_FRAMES 64
/**
* struct udp_tap_port - Port tracking based on tap-facing source port
@ -168,10 +170,78 @@ enum udp_act_type {
/* Activity-based aging for bindings */
static uint8_t udp_act[IP_VERSIONS][UDP_ACT_TYPE_MAX][USHRT_MAX / 8];
/* recvmmsg()/sendmmsg() data */
/* Static buffers */
/**
* udp4_l2_buf_t - Pre-cooked IPv4 packet buffers for tap connections
* @s_in: Source socket address, filled in by recvmmsg()
* @psum: Partial IP header checksum (excluding tot_len and saddr)
* @vnet_len: 4-byte qemu vnet buffer length descriptor, only for passt mode
* @eh: Pre-filled Ethernet header
* @iph: Pre-filled IP header (except for tot_len and saddr)
* @uh: Headroom for UDP header
* @data: Storage for UDP payload
*/
__extension__ static struct udp4_l2_buf_t {
struct sockaddr_in s_in;
uint32_t psum;
uint32_t vnet_len;
struct ethhdr eh;
struct iphdr iph;
struct udphdr uh;
uint8_t data[USHRT_MAX - sizeof(struct udphdr)];
} __attribute__ ((packed, aligned(__alignof__(unsigned int))))
udp4_l2_buf[UDP_TAP_FRAMES] = {
[ 0 ... UDP_TAP_FRAMES - 1 ] = {
{ 0 }, 0, 0, L2_BUF_ETH_IP4_INIT, L2_BUF_IP4_INIT(IPPROTO_UDP),
{ 0 }, { 0 },
},
};
/**
* udp4_l2_buf_t - Pre-cooked IPv6 packet buffers for tap connections
* @s_in6: Source socket address, filled in by recvmmsg()
* @vnet_len: 4-byte qemu vnet buffer length descriptor, only for passt mode
* @eh: Pre-filled Ethernet header
* @ip6h: Pre-filled IP header (except for payload_len and addresses)
* @uh: Headroom for UDP header
* @data: Storage for UDP payload
*/
__extension__ struct udp6_l2_buf_t {
struct sockaddr_in6 s_in6;
uint32_t vnet_len;
struct ethhdr eh;
struct ipv6hdr ip6h;
struct udphdr uh;
uint8_t data[USHRT_MAX -
(sizeof(struct ipv6hdr) + sizeof(struct udphdr))];
} __attribute__ ((packed, aligned(__alignof__(unsigned int))))
udp6_l2_buf[UDP_TAP_FRAMES] = {
[ 0 ... UDP_TAP_FRAMES - 1 ] = {
{ 0 }, 0, L2_BUF_ETH_IP6_INIT, L2_BUF_IP6_INIT(IPPROTO_UDP),
{ 0 }, { 0 },
},
};
static struct sockaddr_storage udp_splice_namebuf;
static uint8_t udp_splice_buf[UDP_SPLICE_FRAMES][USHRT_MAX];
/* recvmmsg()/sendmmsg() data for tap */
static struct iovec udp4_l2_iov_sock [UDP_TAP_FRAMES];
static struct iovec udp6_l2_iov_sock [UDP_TAP_FRAMES];
static struct iovec udp4_l2_iov_tap [UDP_TAP_FRAMES];
static struct iovec udp6_l2_iov_tap [UDP_TAP_FRAMES];
static struct mmsghdr udp4_l2_mh_sock [UDP_TAP_FRAMES];
static struct mmsghdr udp6_l2_mh_sock [UDP_TAP_FRAMES];
static struct mmsghdr udp4_l2_mh_tap [UDP_TAP_FRAMES];
static struct mmsghdr udp6_l2_mh_tap [UDP_TAP_FRAMES];
/* recvmmsg()/sendmmsg() data for "spliced" connections */
static struct iovec udp_splice_iov_recv [UDP_SPLICE_FRAMES];
static struct mmsghdr udp_splice_mmh_recv [UDP_SPLICE_FRAMES];
@ -181,6 +251,118 @@ static struct mmsghdr udp_splice_mmh_send [UDP_SPLICE_FRAMES];
static struct iovec udp_splice_iov_sendto [UDP_SPLICE_FRAMES];
static struct mmsghdr udp_splice_mmh_sendto [UDP_SPLICE_FRAMES];
/**
* udp_update_check4() - Update checksum with variable parts from stored one
* @buf: L2 packet buffer with final IPv4 header
*/
static void udp_update_check4(struct udp4_l2_buf_t *buf)
{
uint32_t sum = buf->psum;
sum += buf->iph.tot_len;
sum += (buf->iph.saddr >> 16) & 0xffff;
sum += buf->iph.saddr & 0xffff;
buf->iph.check = (uint16_t)~csum_fold(sum);
}
/**
* udp_update_l2_buf() - Update L2 buffers with Ethernet and IPv4 addresses
* @eth_d: Ethernet destination address, NULL if unchanged
* @eth_s: Ethernet source address, NULL if unchanged
* @ip_da: Pointer to IPv4 destination address, NULL if unchanged
*/
void udp_update_l2_buf(unsigned char *eth_d, unsigned char *eth_s,
uint32_t *ip_da)
{
int i;
for (i = 0; i < UDP_TAP_FRAMES; i++) {
struct udp4_l2_buf_t *b4 = &udp4_l2_buf[i];
struct udp6_l2_buf_t *b6 = &udp6_l2_buf[i];
if (eth_d) {
memcpy(b4->eh.h_dest, eth_d, ETH_ALEN);
memcpy(b6->eh.h_dest, eth_d, ETH_ALEN);
}
if (eth_s) {
memcpy(b4->eh.h_source, eth_s, ETH_ALEN);
memcpy(b6->eh.h_source, eth_s, ETH_ALEN);
}
if (ip_da) {
b4->iph.daddr = *ip_da;
if (!i) {
b4->iph.saddr = 0;
b4->iph.tot_len = 0;
b4->iph.check = 0;
b4->psum = sum_16b(&b4->iph, 20);
} else {
b4->psum = udp4_l2_buf[0].psum;
}
}
}
}
/**
* udp_sock4_iov_init() - Initialise scatter-gather L2 buffers for IPv4 sockets
*/
static void udp_sock4_iov_init(void)
{
struct mmsghdr *h;
int i;
for (i = 0, h = udp4_l2_mh_sock; i < UDP_TAP_FRAMES; i++, h++) {
struct msghdr *mh = &h->msg_hdr;
mh->msg_name = &udp4_l2_buf[i].s_in;
mh->msg_namelen = sizeof(udp4_l2_buf[i].s_in);
udp4_l2_iov_sock[i].iov_base = udp4_l2_buf[i].data;
udp4_l2_iov_sock[i].iov_len = sizeof(udp4_l2_buf[i].data);
mh->msg_iov = &udp4_l2_iov_sock[i];
mh->msg_iovlen = 1;
}
for (i = 0, h = udp4_l2_mh_tap; i < UDP_TAP_FRAMES; i++, h++) {
struct msghdr *mh = &h->msg_hdr;
udp4_l2_iov_tap[i].iov_base = &udp4_l2_buf[i].vnet_len;
mh->msg_iov = &udp4_l2_iov_tap[i];
mh->msg_iovlen = 1;
}
}
/**
* udp_sock6_iov_init() - Initialise scatter-gather L2 buffers for IPv6 sockets
*/
static void udp_sock6_iov_init(void)
{
struct mmsghdr *h;
int i;
for (i = 0, h = udp6_l2_mh_sock; i < UDP_TAP_FRAMES; i++, h++) {
struct msghdr *mh = &h->msg_hdr;
mh->msg_name = &udp6_l2_buf[i].s_in6;
mh->msg_namelen = sizeof(struct sockaddr_in6);
udp6_l2_iov_sock[i].iov_base = udp6_l2_buf[i].data;
udp6_l2_iov_sock[i].iov_len = sizeof(udp6_l2_buf[i].data);
mh->msg_iov = &udp6_l2_iov_sock[i];
mh->msg_iovlen = 1;
}
for (i = 0, h = udp6_l2_mh_tap; i < UDP_TAP_FRAMES; i++, h++) {
struct msghdr *mh = &h->msg_hdr;
udp6_l2_iov_tap[i].iov_base = &udp6_l2_buf[i].vnet_len;
mh->msg_iov = &udp6_l2_iov_tap[i];
mh->msg_iovlen = 1;
}
}
/**
* udp_splice_connect() - Create and connect socket for "spliced" binding
* @c: Execution context
@ -417,11 +599,9 @@ static void udp_sock_handler_splice(struct ctx *c, union epoll_ref ref,
void udp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events,
struct timespec *now)
{
struct sockaddr_storage sr;
socklen_t sl = sizeof(sr);
char buf[USHRT_MAX];
struct udphdr *uh;
ssize_t n;
int i, iov_in_msg, msg_i = 0;
struct msghdr *cur_mh;
ssize_t n, msglen;
if (events == EPOLLERR)
return;
@ -431,52 +611,158 @@ void udp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events,
return;
}
uh = (struct udphdr *)buf;
n = recvfrom(ref.s, buf + sizeof(*uh), sizeof(buf) - sizeof(*uh), 0,
(struct sockaddr *)&sr, &sl);
if (n < 0)
return;
uh->dest = htons(ref.udp.port);
uh->len = htons(n + sizeof(*uh));
if (ref.udp.v6) {
struct sockaddr_in6 *sr6 = (struct sockaddr_in6 *)&sr;
n = recvmmsg(ref.s, udp6_l2_mh_sock, UDP_TAP_FRAMES, 0, NULL);
if (n <= 0)
return;
if (IN6_IS_ADDR_LOOPBACK(&sr6->sin6_addr)) {
in_port_t src = htons(sr6->sin6_port);
cur_mh = &udp6_l2_mh_tap[msg_i].msg_hdr;
cur_mh->msg_iov = &udp6_l2_iov_tap[0];
msg_i = msglen = iov_in_msg = 0;
/* TODO: Explicit AVX2 vectorisation of this loop */
for (i = 0; i < n; i++) {
struct udp6_l2_buf_t *b = &udp6_l2_buf[i];
size_t ip_len, iov_len;
memcpy(&sr6->sin6_addr, &c->gw6, sizeof(c->gw6));
udp_tap_map[V6][src].ts_local = now->tv_sec;
bitmap_set(udp_act[V6][UDP_ACT_TAP], src);
ip_len = udp6_l2_mh_sock[i].msg_len +
sizeof(b->ip6h) + sizeof(b->uh);
b->ip6h.payload_len = htons(udp6_l2_mh_sock[i].msg_len +
sizeof(b->uh));
if (IN6_IS_ADDR_LOOPBACK(&b->s_in6.sin6_addr) ||
!memcmp(&b->s_in6.sin6_addr, &c->addr6_seen,
sizeof(c->addr6))) {
in_port_t src = htons(b->s_in6.sin6_port);
b->ip6h.daddr = c->addr6_seen;
b->ip6h.saddr = c->gw6;
udp_tap_map[V6][src].ts_local = now->tv_sec;
bitmap_set(udp_act[V6][UDP_ACT_TAP], src);
} else if (IN6_IS_ADDR_LINKLOCAL(&b->s_in6.sin6_addr)) {
b->ip6h.daddr = c->addr6_ll_seen;
b->ip6h.saddr = b->s_in6.sin6_addr;
} else {
b->ip6h.daddr = c->addr6_seen;
b->ip6h.saddr = b->s_in6.sin6_addr;
}
b->uh.source = b->s_in6.sin6_port;
b->uh.dest = htons(ref.udp.port);
b->uh.len = b->ip6h.payload_len;
b->ip6h.hop_limit = IPPROTO_UDP;
b->ip6h.version = 0;
b->ip6h.nexthdr = 0;
b->uh.check = 0;
b->uh.check = csum_ip4(&b->ip6h, ip_len);
b->ip6h.version = 6;
b->ip6h.nexthdr = IPPROTO_UDP;
b->ip6h.hop_limit = 255;
if (c->mode == MODE_PASTA) {
ip_len += sizeof(struct ethhdr);
write(c->fd_tap, &b->eh, ip_len);
pcap((char *)&b->eh, ip_len);
continue;
}
b->vnet_len = htonl(ip_len + sizeof(struct ethhdr));
iov_len = sizeof(uint32_t) + sizeof(struct ethhdr) +
ip_len;
udp6_l2_iov_tap[i].iov_len = iov_len;
/* With bigger messages, qemu closes the connection. */
if (iov_in_msg && msglen + iov_len > SHRT_MAX) {
cur_mh->msg_iovlen = iov_in_msg;
cur_mh = &udp6_l2_mh_tap[++msg_i].msg_hdr;
msglen = iov_in_msg = 0;
cur_mh->msg_iov = &udp6_l2_iov_tap[i];
}
msglen += iov_len;
iov_in_msg++;
}
uh->source = sr6->sin6_port;
if (c->mode == MODE_PASTA)
return;
tap_ip_send(c, &sr6->sin6_addr, IPPROTO_UDP,
buf, n + sizeof(*uh));
cur_mh->msg_iovlen = iov_in_msg;
sendmmsg(c->fd_tap, udp6_l2_mh_tap, msg_i + 1,
MSG_NOSIGNAL | MSG_DONTWAIT);
pcapmm(udp6_l2_mh_tap, msg_i + 1);
} else {
struct in6_addr a6 = { .s6_addr = { 0, 0, 0, 0,
0, 0, 0, 0,
0, 0, 0xff, 0xff,
0, 0, 0, 0 } };
struct sockaddr_in *sr4 = (struct sockaddr_in *)&sr;
n = recvmmsg(ref.s, udp4_l2_mh_sock, UDP_TAP_FRAMES, 0, NULL);
if (n <= 0)
return;
if (ntohl(sr4->sin_addr.s_addr) == INADDR_LOOPBACK ||
ntohl(sr4->sin_addr.s_addr) == INADDR_ANY) {
in_port_t src = htons(sr4->sin_port);
cur_mh = &udp4_l2_mh_tap[msg_i].msg_hdr;
cur_mh->msg_iov = &udp4_l2_iov_tap[0];
msg_i = msglen = iov_in_msg = 0;
/* TODO: Explicit AVX2 vectorisation of this loop */
for (i = 0; i < n; i++) {
struct udp4_l2_buf_t *b = &udp4_l2_buf[i];
size_t ip_len, iov_len;
sr4->sin_addr.s_addr = c->gw4;
udp_tap_map[V4][src].ts_local = now->tv_sec;
bitmap_set(udp_act[V4][UDP_ACT_TAP], src);
ip_len = udp4_l2_mh_sock[i].msg_len +
sizeof(b->iph) + sizeof(b->uh);
b->iph.tot_len = htons(ip_len);
if (ntohl(b->s_in.sin_addr.s_addr) == INADDR_LOOPBACK ||
ntohl(b->s_in.sin_addr.s_addr) == INADDR_ANY ||
b->s_in.sin_addr.s_addr == c->addr4_seen) {
in_port_t src = htons(b->s_in.sin_port);
b->iph.saddr = c->gw4;
udp_tap_map[V4][src].ts_local = now->tv_sec;
bitmap_set(udp_act[V4][UDP_ACT_TAP], src);
} else {
b->iph.saddr = b->s_in.sin_addr.s_addr;
}
udp_update_check4(b);
b->uh.source = b->s_in.sin_port;
b->uh.dest = htons(ref.udp.port);
b->uh.len = ntohs(udp4_l2_mh_sock[i].msg_len +
sizeof(b->uh));
if (c->mode == MODE_PASTA) {
ip_len += sizeof(struct ethhdr);
write(c->fd_tap, &b->eh, ip_len);
pcap((char *)&b->eh, ip_len);
continue;
}
b->vnet_len = htonl(ip_len + sizeof(struct ethhdr));
iov_len = sizeof(uint32_t) + sizeof(struct ethhdr) +
ip_len;
udp4_l2_iov_tap[i].iov_len = iov_len;
/* With bigger messages, qemu closes the connection. */
if (iov_in_msg && msglen + iov_len > SHRT_MAX) {
cur_mh->msg_iovlen = iov_in_msg;
cur_mh = &udp4_l2_mh_tap[++msg_i].msg_hdr;
msglen = iov_in_msg = 0;
cur_mh->msg_iov = &udp4_l2_iov_tap[i];
}
msglen += iov_len;
iov_in_msg++;
}
memcpy(&a6.s6_addr[12], &sr4->sin_addr, sizeof(sr4->sin_addr));
if (c->mode == MODE_PASTA)
return;
uh->source = sr4->sin_port;
cur_mh->msg_iovlen = iov_in_msg;
tap_ip_send(c, &a6, IPPROTO_UDP, buf, n + sizeof(*uh));
sendmmsg(c->fd_tap, udp4_l2_mh_tap, msg_i + 1,
MSG_NOSIGNAL | MSG_DONTWAIT);
pcapmm(udp4_l2_mh_tap, msg_i + 1);
}
}
@ -533,6 +819,7 @@ int udp_tap_handler(struct ctx *c, int af, void *addr,
return count;
udp_tap_map[V4][src].sock = s;
udp_tap_map[V4][src].ts = s;
bitmap_set(udp_act[V4][UDP_ACT_TAP], src);
}
@ -718,6 +1005,12 @@ int udp_sock_init(struct ctx *c)
}
}
if (c->v4)
udp_sock4_iov_init();
if (c->v6)
udp_sock6_iov_init();
if (c->mode == MODE_PASTA) {
udp_splice_iov_init();
clone(udp_sock_init_ns, ns_fn_stack + sizeof(ns_fn_stack) / 2,
@ -772,7 +1065,7 @@ static void udp_timer_one(struct ctx *c, int v6, enum udp_act_type type,
return;
}
if (s != -1) {
if (s > 0) {
epoll_ctl(c->epollfd, EPOLL_CTL_DEL, s, NULL);
close(s);
bitmap_clear(udp_act[v6 ? V6 : V4][type], port);

2
udp.h
View File

@ -9,6 +9,8 @@ int udp_tap_handler(struct ctx *c, int af, void *addr,
struct tap_msg *msg, int count, struct timespec *now);
int udp_sock_init(struct ctx *c);
void udp_timer(struct ctx *c, struct timespec *ts);
void udp_update_l2_buf(unsigned char *eth_d, unsigned char *eth_s,
uint32_t *ip_da);
/**
* union udp_epoll_ref - epoll reference portion for TCP connections

40
util.c
View File

@ -76,6 +76,29 @@ logfn(info, LOG_INFO)
logfn(debug, LOG_DEBUG)
#endif
/**
* sum_16b() - Calculate sum of 16-bit words
* @buf: Input buffer
* @len: Buffer length
*
* Return: 32-bit sum of 16-bit words
*/
uint32_t sum_16b(void *buf, size_t len)
{
uint32_t sum = 0;
uint16_t *p = buf;
size_t len1 = len / 2;
size_t off;
for (off = 0; off < len1; off++, p++)
sum += *p;
if (len % 2)
sum += *p & 0xff;
return sum;
}
/**
* csum_fold() - Fold long sum for IP and TCP checksum
* @sum: Original long sum
@ -91,7 +114,7 @@ uint16_t csum_fold(uint32_t sum)
}
/**
* csum_ipv4() - Calculate IPv4 checksum
* csum_ip4() - Calculate IPv4 checksum
* @buf: Packet buffer, L3 headers
* @len: Total L3 packet length
*
@ -99,22 +122,11 @@ uint16_t csum_fold(uint32_t sum)
*/
uint16_t csum_ip4(void *buf, size_t len)
{
uint32_t sum = 0;
uint16_t *p = buf;
size_t len1 = len / 2;
size_t off;
for (off = 0; off < len1; off++, p++)
sum += *p;
if (len % 2)
sum += *p & 0xff;
return ~csum_fold(sum);
return ~csum_fold(sum_16b(buf, len));
}
/**
* csum_ipv4() - Calculate TCP checksum for IPv4 and set in place
* csum_tcp4() - Calculate TCP checksum for IPv4 and set in place
* @iph: Packet buffer, IP header
*/
void csum_tcp4(struct iphdr *iph)

59
util.h
View File

@ -52,6 +52,64 @@ void debug(const char *format, ...);
#define NS_FN_STACK_SIZE (RLIMIT_STACK_VAL * 1024 / 4)
#if __BYTE_ORDER == __BIG_ENDIAN
#define L2_BUF_ETH_IP4_INIT \
{ \
.h_dest = { 0 }, \
.h_source = { 0 }, \
.h_proto = ETH_P_IP, \
}
#else
#define L2_BUF_ETH_IP4_INIT \
{ \
.h_dest = { 0 }, \
.h_source = { 0 }, \
.h_proto = __bswap_constant_16(ETH_P_IP), \
}
#endif
#if __BYTE_ORDER == __BIG_ENDIAN
#define L2_BUF_ETH_IP6_INIT \
{ \
.h_dest = { 0 }, \
.h_source = { 0 }, \
.h_proto = ETH_P_IPV6, \
}
#else
#define L2_BUF_ETH_IP6_INIT \
{ \
.h_dest = { 0 }, \
.h_source = { 0 }, \
.h_proto = __bswap_constant_16(ETH_P_IPV6), \
}
#endif
#define L2_BUF_IP4_INIT(proto) \
{ \
.version = 4, \
.ihl = 5, \
.tos = 0, \
.tot_len = 0, \
.id = 0, \
.frag_off = 0, \
.ttl = 255, \
.protocol = (proto), \
.saddr = 0, \
.daddr = 0, \
}
#define L2_BUF_IP6_INIT(proto) \
{ \
.priority = 0, \
.version = 6, \
.flow_lbl = { 0 }, \
.payload_len = 0, \
.nexthdr = (proto), \
.hop_limit = 255, \
.saddr = IN6ADDR_ANY_INIT, \
.daddr = IN6ADDR_ANY_INIT, \
}
#include <linux/ipv6.h>
#include <net/if.h>
#include <linux/ip.h>
@ -59,6 +117,7 @@ void debug(const char *format, ...);
struct ctx;
uint32_t sum_16b(void *buf, size_t len);
uint16_t csum_fold(uint32_t sum);
uint16_t csum_ip4(void *buf, size_t len);
void csum_tcp4(struct iphdr *iph);