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udp: Use abstracted tap header

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Update the UDP code to use the tap layer abstractions for initializing and
updating the L2 and lower headers.  This will make adding other tap
backends in future easier.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
David Gibson 2023-01-06 11:43:20 +11:00 committed by Stefano Brivio
parent 0fb7b2b908
commit 97d1ca2ed6
2 changed files with 24 additions and 62 deletions
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79
udp.c
View file

@ -169,8 +169,7 @@ static uint8_t udp_act[IP_VERSIONS][UDP_ACT_TYPE_MAX][DIV_ROUND_UP(NUM_PORTS, 8)
* udp4_l2_buf_t - Pre-cooked IPv4 packet buffers for tap connections * udp4_l2_buf_t - Pre-cooked IPv4 packet buffers for tap connections
* @s_in: Source socket address, filled in by recvmmsg() * @s_in: Source socket address, filled in by recvmmsg()
* @psum: Partial IP header checksum (excluding tot_len and saddr) * @psum: Partial IP header checksum (excluding tot_len and saddr)
* @vnet_len: 4-byte qemu vnet buffer length descriptor, only for passt mode * @taph: Tap-level headers (partially pre-filled)
* @eh: Pre-filled Ethernet header
* @iph: Pre-filled IP header (except for tot_len and saddr) * @iph: Pre-filled IP header (except for tot_len and saddr)
* @uh: Headroom for UDP header * @uh: Headroom for UDP header
* @data: Storage for UDP payload * @data: Storage for UDP payload
@ -179,8 +178,7 @@ static struct udp4_l2_buf_t {
struct sockaddr_in s_in; struct sockaddr_in s_in;
uint32_t psum; uint32_t psum;
uint32_t vnet_len; struct tap_hdr taph;
struct ethhdr eh;
struct iphdr iph; struct iphdr iph;
struct udphdr uh; struct udphdr uh;
uint8_t data[USHRT_MAX - uint8_t data[USHRT_MAX -
@ -191,8 +189,7 @@ udp4_l2_buf[UDP_MAX_FRAMES];
/** /**
* udp6_l2_buf_t - Pre-cooked IPv6 packet buffers for tap connections * udp6_l2_buf_t - Pre-cooked IPv6 packet buffers for tap connections
* @s_in6: Source socket address, filled in by recvmmsg() * @s_in6: Source socket address, filled in by recvmmsg()
* @vnet_len: 4-byte qemu vnet buffer length descriptor, only for passt mode * @taph: Tap-level headers (partially pre-filled)
* @eh: Pre-filled Ethernet header
* @ip6h: Pre-filled IP header (except for payload_len and addresses) * @ip6h: Pre-filled IP header (except for payload_len and addresses)
* @uh: Headroom for UDP header * @uh: Headroom for UDP header
* @data: Storage for UDP payload * @data: Storage for UDP payload
@ -205,8 +202,7 @@ struct udp6_l2_buf_t {
sizeof(uint32_t))]; sizeof(uint32_t))];
#endif #endif
uint32_t vnet_len; struct tap_hdr taph;
struct ethhdr eh;
struct ipv6hdr ip6h; struct ipv6hdr ip6h;
struct udphdr uh; struct udphdr uh;
uint8_t data[USHRT_MAX - uint8_t data[USHRT_MAX -
@ -294,15 +290,8 @@ void udp_update_l2_buf(const unsigned char *eth_d, const unsigned char *eth_s,
struct udp4_l2_buf_t *b4 = &udp4_l2_buf[i]; struct udp4_l2_buf_t *b4 = &udp4_l2_buf[i];
struct udp6_l2_buf_t *b6 = &udp6_l2_buf[i]; struct udp6_l2_buf_t *b6 = &udp6_l2_buf[i];
if (eth_d) { tap_update_mac(&b4->taph, eth_d, eth_s);
memcpy(b4->eh.h_dest, eth_d, ETH_ALEN); tap_update_mac(&b6->taph, eth_d, eth_s);
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) { if (ip_da) {
b4->iph.daddr = ip_da->s_addr; b4->iph.daddr = ip_da->s_addr;
@ -329,7 +318,7 @@ static void udp_sock4_iov_init(const struct ctx *c)
for (i = 0; i < ARRAY_SIZE(udp4_l2_buf); i++) { for (i = 0; i < ARRAY_SIZE(udp4_l2_buf); i++) {
udp4_l2_buf[i] = (struct udp4_l2_buf_t) { udp4_l2_buf[i] = (struct udp4_l2_buf_t) {
.eh = L2_BUF_ETH_INIT(ETH_P_IP), .taph = TAP_HDR_INIT(ETH_P_IP),
.iph = L2_BUF_IP4_INIT(IPPROTO_UDP) .iph = L2_BUF_IP4_INIT(IPPROTO_UDP)
}; };
} }
@ -346,16 +335,13 @@ static void udp_sock4_iov_init(const struct ctx *c)
mh->msg_iovlen = 1; mh->msg_iovlen = 1;
} }
for (i = 0, h = udp4_l2_mh_tap; i < UDP_MAX_FRAMES; i++, h++) { for (i = 0; i < UDP_MAX_FRAMES; i++) {
struct msghdr *mh = &h->msg_hdr; struct msghdr *mh = &udp4_l2_mh_tap[i].msg_hdr;
struct iovec *iov = &udp4_l2_iov_tap[i];
if (c->mode == MODE_PASTA) iov->iov_base = tap_iov_base(c, &udp4_l2_buf[i].taph);
udp4_l2_iov_tap[i].iov_base = &udp4_l2_buf[i].eh; mh->msg_iov = iov;
else mh->msg_iovlen = 1;
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;
} }
} }
@ -370,7 +356,7 @@ static void udp_sock6_iov_init(const struct ctx *c)
for (i = 0; i < ARRAY_SIZE(udp6_l2_buf); i++) { for (i = 0; i < ARRAY_SIZE(udp6_l2_buf); i++) {
udp6_l2_buf[i] = (struct udp6_l2_buf_t) { udp6_l2_buf[i] = (struct udp6_l2_buf_t) {
.eh = L2_BUF_ETH_INIT(ETH_P_IPV6), .taph = TAP_HDR_INIT(ETH_P_IPV6),
.ip6h = L2_BUF_IP6_INIT(IPPROTO_UDP) .ip6h = L2_BUF_IP6_INIT(IPPROTO_UDP)
}; };
} }
@ -387,16 +373,13 @@ static void udp_sock6_iov_init(const struct ctx *c)
mh->msg_iovlen = 1; mh->msg_iovlen = 1;
} }
for (i = 0, h = udp6_l2_mh_tap; i < UDP_MAX_FRAMES; i++, h++) { for (i = 0; i < UDP_MAX_FRAMES; i++) {
struct msghdr *mh = &h->msg_hdr; struct msghdr *mh = &udp6_l2_mh_tap[i].msg_hdr;
struct iovec *iov = &udp6_l2_iov_tap[i];
if (c->mode == MODE_PASTA) iov->iov_base = tap_iov_base(c, &udp6_l2_buf[i].taph);
udp6_l2_iov_tap[i].iov_base = &udp6_l2_buf[i].eh; mh->msg_iov = iov;
else mh->msg_iovlen = 1;
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;
} }
} }
@ -607,8 +590,8 @@ static size_t udp_update_hdr4(const struct ctx *c, int n, in_port_t dstport,
const struct timespec *now) const struct timespec *now)
{ {
struct udp4_l2_buf_t *b = &udp4_l2_buf[n]; struct udp4_l2_buf_t *b = &udp4_l2_buf[n];
size_t ip_len, buf_len;
in_port_t src_port; in_port_t src_port;
size_t ip_len;
ip_len = udp4_l2_mh_sock[n].msg_len + sizeof(b->iph) + sizeof(b->uh); ip_len = udp4_l2_mh_sock[n].msg_len + sizeof(b->iph) + sizeof(b->uh);
@ -642,14 +625,7 @@ static size_t udp_update_hdr4(const struct ctx *c, int n, in_port_t dstport,
b->uh.dest = htons(dstport); b->uh.dest = htons(dstport);
b->uh.len = htons(udp4_l2_mh_sock[n].msg_len + sizeof(b->uh)); b->uh.len = htons(udp4_l2_mh_sock[n].msg_len + sizeof(b->uh));
buf_len = ip_len + sizeof(b->eh); return tap_iov_len(c, &b->taph, ip_len);
if (c->mode == MODE_PASST) {
b->vnet_len = htonl(buf_len);
buf_len += sizeof(b->vnet_len);
}
return buf_len;
} }
/** /**
@ -665,9 +641,9 @@ static size_t udp_update_hdr6(const struct ctx *c, int n, in_port_t dstport,
const struct timespec *now) const struct timespec *now)
{ {
struct udp6_l2_buf_t *b = &udp6_l2_buf[n]; struct udp6_l2_buf_t *b = &udp6_l2_buf[n];
size_t ip_len, buf_len;
struct in6_addr *src; struct in6_addr *src;
in_port_t src_port; in_port_t src_port;
size_t ip_len;
src = &b->s_in6.sin6_addr; src = &b->s_in6.sin6_addr;
src_port = ntohs(b->s_in6.sin6_port); src_port = ntohs(b->s_in6.sin6_port);
@ -724,14 +700,7 @@ static size_t udp_update_hdr6(const struct ctx *c, int n, in_port_t dstport,
b->ip6h.nexthdr = IPPROTO_UDP; b->ip6h.nexthdr = IPPROTO_UDP;
b->ip6h.hop_limit = 255; b->ip6h.hop_limit = 255;
buf_len = ip_len + sizeof(b->eh); return tap_iov_len(c, &b->taph, ip_len);
if (c->mode == MODE_PASST) {
b->vnet_len = htonl(buf_len);
buf_len += sizeof(b->vnet_len);
}
return buf_len;
} }
/** /**

7
util.h
View file

@ -102,13 +102,6 @@ int do_clone(int (*fn)(void *), char *stack_area, size_t stack_size, int flags,
(void *)(arg)); \ (void *)(arg)); \
} while (0) } while (0)
#define L2_BUF_ETH_INIT(proto) \
{ \
.h_dest = { 0 }, \
.h_source = { 0 }, \
.h_proto = htons_constant(proto), \
}
#define L2_BUF_IP4_INIT(proto) \ #define L2_BUF_IP4_INIT(proto) \
{ \ { \
.version = 4, \ .version = 4, \