mirror of
https://passt.top/passt
synced 2025-06-22 06:45:33 +02:00
passt: Introduce packet batching mechanism
Receive packets in batches from AF_UNIX, check if they can be sent with a single syscall, and batch them up with sendmmsg() in case. A bit rudimentary, currently only implemented for UDP, but it seems to work. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
Stefano Brivio
parent
5b0c88d4ef
commit
1f7cf04d34
8 changed files with 337 additions and 122 deletions
290
passt.c
290
passt.c
|
|
@ -19,6 +19,7 @@
|
|||
#include <sys/types.h>
|
||||
#include <sys/ioctl.h>
|
||||
#include <sys/resource.h>
|
||||
#include <sys/uio.h>
|
||||
#include <sys/un.h>
|
||||
#include <ifaddrs.h>
|
||||
#include <linux/if_ether.h>
|
||||
|
|
@ -56,7 +57,9 @@
|
|||
|
||||
#define EPOLL_EVENTS 10
|
||||
|
||||
#define TIMER_INTERVAL 20 /* ms, for protocol periodic handlers */
|
||||
#define TAP_NMSG 32 /* maximum messages to buffer from tap */
|
||||
|
||||
#define TIMER_INTERVAL 100 /* ms, for protocol periodic handlers */
|
||||
|
||||
/**
|
||||
* sock_unix() - Create and bind AF_UNIX socket, add to epoll list
|
||||
|
|
@ -303,87 +306,182 @@ static void get_dns(struct ctx *c)
|
|||
/**
|
||||
* tap4_handler() - IPv4 and ARP packet handler for tap file descriptor
|
||||
* @c: Execution context
|
||||
* @len: Total L2 packet length
|
||||
* @in: Packet buffer, L2 headers
|
||||
* @msg: Array of messages with the same L3 protocol
|
||||
* @count: Count of messages with the same L3 protocol
|
||||
*
|
||||
* Return: count of packets consumed by handlers
|
||||
*/
|
||||
static void tap4_handler(struct ctx *c, char *in, size_t len)
|
||||
static int tap4_handler(struct ctx *c, struct tap_msg *msg, size_t count)
|
||||
{
|
||||
char buf_s[INET_ADDRSTRLEN] __attribute((__unused__));
|
||||
char buf_d[INET_ADDRSTRLEN] __attribute((__unused__));
|
||||
struct ethhdr *eh = (struct ethhdr *)in;
|
||||
struct iphdr *iph = (struct iphdr *)(eh + 1);
|
||||
struct ethhdr *eh = (struct ethhdr *)msg[0].start;
|
||||
struct iphdr *iph, *prev_iph = NULL;
|
||||
struct udphdr *uh, *prev_uh = NULL;
|
||||
size_t len = msg[0].len;
|
||||
unsigned int i;
|
||||
char *l4h;
|
||||
|
||||
if (!c->v4)
|
||||
return;
|
||||
|
||||
if (arp(c, eh, len) || dhcp(c, eh, len))
|
||||
return;
|
||||
return count;
|
||||
|
||||
if (len < sizeof(*eh) + sizeof(*iph))
|
||||
return;
|
||||
return 1;
|
||||
|
||||
l4h = (char *)iph + iph->ihl * 4;
|
||||
len -= (intptr_t)l4h - (intptr_t)eh;
|
||||
if (arp(c, eh, len) || dhcp(c, eh, len))
|
||||
return 1;
|
||||
|
||||
if (iph->protocol == IPPROTO_ICMP) {
|
||||
for (i = 0; i < count; i++) {
|
||||
len = msg[i].len;
|
||||
if (len < sizeof(*eh) + sizeof(*iph))
|
||||
return 1;
|
||||
|
||||
eh = (struct ethhdr *)msg[i].start;
|
||||
iph = (struct iphdr *)(eh + 1);
|
||||
l4h = (char *)iph + iph->ihl * 4;
|
||||
|
||||
msg[i].l4h = l4h;
|
||||
msg[i].l4_len = len - ((intptr_t)l4h - (intptr_t)eh);
|
||||
|
||||
if (iph->protocol != IPPROTO_TCP &&
|
||||
iph->protocol != IPPROTO_UDP)
|
||||
break;
|
||||
|
||||
if (len < sizeof(*uh))
|
||||
break;
|
||||
|
||||
uh = (struct udphdr *)l4h;
|
||||
|
||||
if (!i) {
|
||||
prev_iph = iph;
|
||||
prev_uh = uh;
|
||||
continue;
|
||||
}
|
||||
|
||||
if (iph->tos != prev_iph->tos ||
|
||||
iph->frag_off != prev_iph->frag_off ||
|
||||
iph->protocol != prev_iph->protocol ||
|
||||
iph->saddr != prev_iph->saddr ||
|
||||
iph->daddr != prev_iph->daddr ||
|
||||
uh->source != prev_uh->source ||
|
||||
uh->dest != prev_uh->dest)
|
||||
break;
|
||||
|
||||
prev_iph = iph;
|
||||
prev_uh = uh;
|
||||
}
|
||||
|
||||
eh = (struct ethhdr *)msg[0].start;
|
||||
iph = (struct iphdr *)(eh + 1);
|
||||
|
||||
if (iph->protocol == IPPROTO_TCP || iph->protocol == IPPROTO_UDP ||
|
||||
iph->protocol == IPPROTO_SCTP) {
|
||||
uh = (struct udphdr *)msg[0].l4h;
|
||||
|
||||
if (msg[0].len < sizeof(*uh))
|
||||
return 1;
|
||||
|
||||
debug("%s from tap: %s:%i -> %s:%i (%i packet%s)",
|
||||
getprotobynumber(iph->protocol)->p_name,
|
||||
inet_ntop(AF_INET, &iph->saddr, buf_s, sizeof(buf_s)),
|
||||
ntohs(uh->source),
|
||||
inet_ntop(AF_INET, &iph->daddr, buf_d, sizeof(buf_d)),
|
||||
ntohs(uh->dest),
|
||||
i, i > 1 ? "s" : "");
|
||||
} else if (iph->protocol == IPPROTO_ICMP) {
|
||||
debug("icmp from tap: %s -> %s",
|
||||
inet_ntop(AF_INET, &iph->saddr, buf_s, sizeof(buf_s)),
|
||||
inet_ntop(AF_INET, &iph->daddr, buf_d, sizeof(buf_d)));
|
||||
} else if (iph->protocol == IPPROTO_TCP ||
|
||||
iph->protocol == IPPROTO_UDP ||
|
||||
iph->protocol == IPPROTO_SCTP) {
|
||||
struct tcphdr *th = (struct tcphdr *)l4h;
|
||||
|
||||
if (len < sizeof(*th) && len < sizeof(struct udphdr))
|
||||
return;
|
||||
|
||||
debug("%s from tap: %s:%i -> %s:%i",
|
||||
getprotobynumber(iph->protocol)->p_name,
|
||||
inet_ntop(AF_INET, &iph->saddr, buf_s, sizeof(buf_s)),
|
||||
ntohs(th->source),
|
||||
inet_ntop(AF_INET, &iph->daddr, buf_d, sizeof(buf_d)),
|
||||
ntohs(th->dest));
|
||||
}
|
||||
|
||||
if (iph->protocol == IPPROTO_TCP)
|
||||
tcp_tap_handler(c, AF_INET, &iph->daddr, l4h, len);
|
||||
else if (iph->protocol == IPPROTO_UDP)
|
||||
udp_tap_handler(c, AF_INET, &iph->daddr, l4h, len);
|
||||
else if (iph->protocol == IPPROTO_ICMP)
|
||||
icmp_tap_handler(c, AF_INET, &iph->daddr, l4h, len);
|
||||
return tcp_tap_handler(c, AF_INET, &iph->daddr, msg, i);
|
||||
|
||||
if (iph->protocol == IPPROTO_UDP)
|
||||
return udp_tap_handler(c, AF_INET, &iph->daddr, msg, i);
|
||||
|
||||
if (iph->protocol == IPPROTO_ICMP)
|
||||
icmp_tap_handler(c, AF_INET, &iph->daddr, msg, 1);
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
/**
|
||||
* tap6_handler() - IPv6 packet handler for tap file descriptor
|
||||
* @c: Execution context
|
||||
* @len: Total L2 packet length
|
||||
* @in: Packet buffer, L2 headers
|
||||
* @msg: Array of messages with the same L3 protocol
|
||||
* @count: Count of messages with the same L3 protocol
|
||||
*/
|
||||
static void tap6_handler(struct ctx *c, char *in, size_t len)
|
||||
static int tap6_handler(struct ctx *c, struct tap_msg *msg, size_t count)
|
||||
{
|
||||
char buf_s[INET6_ADDRSTRLEN] __attribute((__unused__));
|
||||
char buf_d[INET6_ADDRSTRLEN] __attribute((__unused__));
|
||||
struct ethhdr *eh = (struct ethhdr *)in;
|
||||
struct ipv6hdr *ip6h = (struct ipv6hdr *)(eh + 1);
|
||||
uint8_t proto;
|
||||
struct ethhdr *eh = (struct ethhdr *)msg[0].start;
|
||||
struct udphdr *uh, *prev_uh = NULL;
|
||||
uint8_t proto = 0, prev_proto = 0;
|
||||
size_t len = msg[0].len;
|
||||
struct ipv6hdr *ip6h;
|
||||
unsigned int i;
|
||||
char *l4h;
|
||||
|
||||
if (!c->v6)
|
||||
return;
|
||||
return count;
|
||||
|
||||
if (len < sizeof(*eh) + sizeof(*ip6h))
|
||||
return;
|
||||
return 1;
|
||||
|
||||
if (ndp(c, eh, len) || dhcpv6(c, eh, len))
|
||||
return;
|
||||
return 1;
|
||||
|
||||
l4h = ipv6_l4hdr(ip6h, &proto);
|
||||
for (i = 0; i < count; i++) {
|
||||
struct ipv6hdr *p_ip6h;
|
||||
|
||||
c->addr6_guest = ip6h->saddr;
|
||||
ip6h->saddr = c->addr6;
|
||||
len = msg[i].len;
|
||||
if (len < sizeof(*eh) + sizeof(*ip6h))
|
||||
return 1;
|
||||
|
||||
len -= (intptr_t)l4h - (intptr_t)eh;
|
||||
eh = (struct ethhdr *)msg[i].start;
|
||||
ip6h = (struct ipv6hdr *)(eh + 1);
|
||||
l4h = ipv6_l4hdr(ip6h, &proto);
|
||||
|
||||
msg[i].l4h = l4h;
|
||||
msg[i].l4_len = len - ((intptr_t)l4h - (intptr_t)eh);
|
||||
|
||||
c->addr6_guest = ip6h->saddr;
|
||||
ip6h->saddr = c->addr6;
|
||||
|
||||
if (proto != IPPROTO_TCP && proto != IPPROTO_UDP)
|
||||
break;
|
||||
|
||||
if (len < sizeof(*uh))
|
||||
break;
|
||||
|
||||
uh = (struct udphdr *)l4h;
|
||||
|
||||
if (!i) {
|
||||
p_ip6h = ip6h;
|
||||
prev_proto = proto;
|
||||
prev_uh = uh;
|
||||
continue;
|
||||
}
|
||||
|
||||
if (proto != prev_proto ||
|
||||
memcmp(&ip6h->saddr, &p_ip6h->saddr, sizeof(ip6h->saddr)) ||
|
||||
memcmp(&ip6h->daddr, &p_ip6h->daddr, sizeof(ip6h->daddr)) ||
|
||||
uh->source != prev_uh->source ||
|
||||
uh->dest != prev_uh->dest)
|
||||
break;
|
||||
|
||||
p_ip6h = ip6h;
|
||||
prev_proto = proto;
|
||||
prev_uh = uh;
|
||||
}
|
||||
|
||||
if (prev_proto)
|
||||
proto = prev_proto;
|
||||
|
||||
eh = (struct ethhdr *)msg[0].start;
|
||||
ip6h = (struct ipv6hdr *)(eh + 1);
|
||||
|
||||
if (proto == IPPROTO_ICMPV6) {
|
||||
debug("icmpv6 from tap: %s ->\n\t%s",
|
||||
|
|
@ -391,27 +489,34 @@ static void tap6_handler(struct ctx *c, char *in, size_t len)
|
|||
inet_ntop(AF_INET6, &ip6h->daddr, buf_d, sizeof(buf_d)));
|
||||
} else if (proto == IPPROTO_TCP || proto == IPPROTO_UDP ||
|
||||
proto == IPPROTO_SCTP) {
|
||||
struct tcphdr *th = (struct tcphdr *)l4h;
|
||||
uh = (struct udphdr *)msg[0].l4h;
|
||||
|
||||
if (len < sizeof(*th) && len < sizeof(struct udphdr))
|
||||
return;
|
||||
if (msg[0].len < sizeof(*uh))
|
||||
return 1;
|
||||
|
||||
debug("%s from tap: [%s]:%i\n\t-> [%s]:%i",
|
||||
debug("%s from tap: [%s]:%i\n\t-> [%s]:%i (%i packet%s)",
|
||||
getprotobynumber(proto)->p_name,
|
||||
inet_ntop(AF_INET6, &ip6h->saddr, buf_s, sizeof(buf_s)),
|
||||
ntohs(th->source),
|
||||
ntohs(uh->source),
|
||||
inet_ntop(AF_INET6, &ip6h->daddr, buf_d, sizeof(buf_d)),
|
||||
ntohs(th->dest));
|
||||
ntohs(uh->dest),
|
||||
i, i > 1 ? "s" : "");
|
||||
}
|
||||
|
||||
if (proto == IPPROTO_TCP)
|
||||
tcp_tap_handler(c, AF_INET6, &ip6h->daddr, l4h, len);
|
||||
else if (proto == IPPROTO_UDP)
|
||||
udp_tap_handler(c, AF_INET6, &ip6h->daddr, l4h, len);
|
||||
else if (proto == IPPROTO_ICMPV6)
|
||||
icmp_tap_handler(c, AF_INET6, &ip6h->daddr, l4h, len);
|
||||
return tcp_tap_handler(c, AF_INET6, &ip6h->daddr, msg, i);
|
||||
|
||||
if (proto == IPPROTO_UDP)
|
||||
return udp_tap_handler(c, AF_INET6, &ip6h->daddr, msg, i);
|
||||
|
||||
if (proto == IPPROTO_ICMPV6)
|
||||
icmp_tap_handler(c, AF_INET6, &ip6h->daddr, msg, 1);
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
static char tap_buf[ETH_MAX_MTU * TAP_NMSG];
|
||||
|
||||
/**
|
||||
* tap_handler() - Packet handler for tap file descriptor
|
||||
* @c: Execution context
|
||||
|
|
@ -420,33 +525,74 @@ static void tap6_handler(struct ctx *c, char *in, size_t len)
|
|||
*/
|
||||
static int tap_handler(struct ctx *c)
|
||||
{
|
||||
char buf[ETH_MAX_MTU];
|
||||
int msg_count = 0, same, rcv = 0, i = 0;
|
||||
struct tap_msg msg[UIO_MAXIOV];
|
||||
ssize_t n, rem, fill;
|
||||
struct ethhdr *eh;
|
||||
uint32_t vnet_len;
|
||||
ssize_t n;
|
||||
char *p = tap_buf;
|
||||
|
||||
eh = (struct ethhdr *)buf;
|
||||
fill = ETH_MAX_MTU * (TAP_NMSG - 1);
|
||||
|
||||
while ((n = recv(c->fd_unix, &vnet_len, 4, MSG_DONTWAIT)) == 4) {
|
||||
n = recv(c->fd_unix, buf, ntohl(vnet_len), MSG_DONTWAIT);
|
||||
while ((n = recv(c->fd_unix, p, fill, MSG_DONTWAIT)) > 0) {
|
||||
fill -= n;
|
||||
while (n > 0) {
|
||||
ssize_t len = ntohl(*(uint32_t *)p);
|
||||
|
||||
if (n < (ssize_t)sizeof(*eh))
|
||||
break;
|
||||
p += sizeof(uint32_t);
|
||||
n -= sizeof(uint32_t);
|
||||
|
||||
switch (ntohs(eh->h_proto)) {
|
||||
case ETH_P_IP:
|
||||
if (len < (ssize_t)sizeof(*eh))
|
||||
break;
|
||||
|
||||
/* At most one packet might not fit in a single read */
|
||||
if (len > n) {
|
||||
rem = recv(c->fd_unix, p + n, fill,
|
||||
MSG_DONTWAIT);
|
||||
rcv = errno;
|
||||
if (rem <= 0 || rem + n != len)
|
||||
break;
|
||||
}
|
||||
|
||||
msg[msg_count].start = p;
|
||||
msg[msg_count++].len = len;
|
||||
|
||||
n -= len;
|
||||
p += len;
|
||||
}
|
||||
}
|
||||
|
||||
rcv = errno;
|
||||
|
||||
while (i < msg_count) {
|
||||
eh = (struct ethhdr *)msg[i].start;
|
||||
switch (ntohs(eh->h_proto)) {
|
||||
case ETH_P_ARP:
|
||||
tap4_handler(c, buf, n);
|
||||
tap4_handler(c, msg + i, 1);
|
||||
i++;
|
||||
break;
|
||||
case ETH_P_IP:
|
||||
for (same = 1; i + same < msg_count; same++) {
|
||||
eh = (struct ethhdr *)msg[i + same].start;
|
||||
if (ntohs(eh->h_proto) != ETH_P_IP)
|
||||
break;
|
||||
}
|
||||
i += tap4_handler(c, msg + i, same);
|
||||
break;
|
||||
case ETH_P_IPV6:
|
||||
tap6_handler(c, buf, n);
|
||||
for (same = 1; i + same < msg_count; same++) {
|
||||
eh = (struct ethhdr *)msg[i + same].start;
|
||||
if (ntohs(eh->h_proto) != ETH_P_IPV6)
|
||||
break;
|
||||
}
|
||||
i += tap6_handler(c, msg + i, same);
|
||||
break;
|
||||
default:
|
||||
i++;
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
if (n >= 0 || errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)
|
||||
if (n >= 0 || rcv == EINTR || rcv == EAGAIN || rcv == EWOULDBLOCK)
|
||||
return 0;
|
||||
|
||||
epoll_ctl(c->epollfd, EPOLL_CTL_DEL, c->fd_unix, NULL);
|
||||
|
|
@ -552,7 +698,7 @@ int main(int argc, char **argv)
|
|||
exit(EXIT_FAILURE);
|
||||
}
|
||||
|
||||
#if DEBUG
|
||||
#if DEBUG || 1
|
||||
openlog("passt", LOG_PERROR, LOG_DAEMON);
|
||||
#else
|
||||
openlog("passt", 0, LOG_DAEMON);
|
||||
|
|
@ -610,7 +756,7 @@ listen:
|
|||
UNIX_SOCK_PATH " -net nic,model=virtio");
|
||||
|
||||
c.fd_unix = accept(fd_unix, NULL, NULL);
|
||||
ev.events = EPOLLIN | EPOLLET | EPOLLRDHUP | EPOLLERR | EPOLLHUP;
|
||||
ev.events = EPOLLIN | EPOLLRDHUP | EPOLLERR | EPOLLHUP;
|
||||
ev.data.fd = c.fd_unix;
|
||||
epoll_ctl(c.epollfd, EPOLL_CTL_ADD, c.fd_unix, &ev);
|
||||
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue