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tcp: Use abstracted tap header

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Update the TCP 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 11:43:18 +11:00 committed by Stefano Brivio
parent 4b3d38a069
commit 2416310a17
1 changed files with 30 additions and 55 deletions
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85
tcp.c
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@ -330,8 +330,7 @@ struct tcp4_l2_head { /* For MSS4 macro: keep in sync with tcp4_l2_buf_t */
#else #else
uint8_t pad[2]; uint8_t pad[2];
#endif #endif
uint32_t vnet_len; struct tap_hdr taph;
struct ethhdr eh;
struct iphdr iph; struct iphdr iph;
struct tcphdr th; struct tcphdr th;
#ifdef __AVX2__ #ifdef __AVX2__
@ -346,8 +345,7 @@ struct tcp6_l2_head { /* For MSS6 macro: keep in sync with tcp6_l2_buf_t */
#else #else
uint8_t pad[2]; uint8_t pad[2];
#endif #endif
uint32_t vnet_len; struct tap_hdr taph;
struct ethhdr eh;
struct ipv6hdr ip6h; struct ipv6hdr ip6h;
struct tcphdr th; struct tcphdr th;
#ifdef __AVX2__ #ifdef __AVX2__
@ -448,8 +446,7 @@ static union inany_addr low_rtt_dst[LOW_RTT_TABLE_SIZE];
* @psum: Partial IP header checksum (excluding tot_len and saddr) * @psum: Partial IP header checksum (excluding tot_len and saddr)
* @tsum: Partial TCP header checksum (excluding length and saddr) * @tsum: Partial TCP header checksum (excluding length and saddr)
* @pad: Align TCP header to 32 bytes, for AVX2 checksum calculation only * @pad: Align TCP header to 32 bytes, for AVX2 checksum calculation only
* @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 TCP header * @uh: Headroom for TCP header
* @data: Storage for TCP payload * @data: Storage for TCP payload
@ -462,8 +459,7 @@ static struct tcp4_l2_buf_t {
#else #else
uint8_t pad[2]; /* align iph to 4 bytes 8 */ uint8_t pad[2]; /* align iph to 4 bytes 8 */
#endif #endif
uint32_t vnet_len; /* 26 10 */ struct tap_hdr taph; /* 26 10 */
struct ethhdr eh; /* 30 14 */
struct iphdr iph; /* 44 28 */ struct iphdr iph; /* 44 28 */
struct tcphdr th; /* 64 48 */ struct tcphdr th; /* 64 48 */
uint8_t data[MSS4]; /* 84 68 */ uint8_t data[MSS4]; /* 84 68 */
@ -480,8 +476,7 @@ static unsigned int tcp4_l2_buf_used;
/** /**
* tcp6_l2_buf_t - Pre-cooked IPv6 packet buffers for tap connections * tcp6_l2_buf_t - Pre-cooked IPv6 packet buffers for tap connections
* @pad: Align IPv6 header for checksum calculation to 32B (AVX2) or 4B * @pad: Align IPv6 header for checksum calculation to 32B (AVX2) or 4B
* @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)
* @th: Headroom for TCP header * @th: Headroom for TCP header
* @data: Storage for TCP payload * @data: Storage for TCP payload
@ -492,8 +487,7 @@ struct tcp6_l2_buf_t {
#else #else
uint8_t pad[2]; /* align ip6h to 4 bytes 0 */ uint8_t pad[2]; /* align ip6h to 4 bytes 0 */
#endif #endif
uint32_t vnet_len; /* 14 2 */ struct tap_hdr taph; /* 14 2 */
struct ethhdr eh; /* 18 6 */
struct ipv6hdr ip6h; /* 32 20 */ struct ipv6hdr ip6h; /* 32 20 */
struct tcphdr th; /* 72 60 */ struct tcphdr th; /* 72 60 */
uint8_t data[MSS6]; /* 92 80 */ uint8_t data[MSS6]; /* 92 80 */
@ -526,8 +520,7 @@ static struct iovec tcp_iov [UIO_MAXIOV];
* @psum: Partial IP header checksum (excluding tot_len and saddr) * @psum: Partial IP header checksum (excluding tot_len and saddr)
* @tsum: Partial TCP header checksum (excluding length and saddr) * @tsum: Partial TCP header checksum (excluding length and saddr)
* @pad: Align TCP header to 32 bytes, for AVX2 checksum calculation only * @pad: Align TCP header to 32 bytes, for AVX2 checksum calculation only
* @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)
* @th: Headroom for TCP header * @th: Headroom for TCP header
* @opts: Headroom for TCP options * @opts: Headroom for TCP options
@ -540,8 +533,7 @@ static struct tcp4_l2_flags_buf_t {
#else #else
uint8_t pad[2]; /* align iph to 4 bytes 8 */ uint8_t pad[2]; /* align iph to 4 bytes 8 */
#endif #endif
uint32_t vnet_len; /* 26 10 */ struct tap_hdr taph; /* 26 10 */
struct ethhdr eh; /* 30 14 */
struct iphdr iph; /* 44 28 */ struct iphdr iph; /* 44 28 */
struct tcphdr th; /* 64 48 */ struct tcphdr th; /* 64 48 */
char opts[OPT_MSS_LEN + OPT_WS_LEN + 1]; char opts[OPT_MSS_LEN + OPT_WS_LEN + 1];
@ -557,8 +549,7 @@ static unsigned int tcp4_l2_flags_buf_used;
/** /**
* tcp6_l2_flags_buf_t - IPv6 packet buffers for segments without data (flags) * tcp6_l2_flags_buf_t - IPv6 packet buffers for segments without data (flags)
* @pad: Align IPv6 header for checksum calculation to 32B (AVX2) or 4B * @pad: Align IPv6 header for checksum calculation to 32B (AVX2) or 4B
* @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)
* @th: Headroom for TCP header * @th: Headroom for TCP header
* @opts: Headroom for TCP options * @opts: Headroom for TCP options
@ -569,8 +560,7 @@ static struct tcp6_l2_flags_buf_t {
#else #else
uint8_t pad[2]; /* align ip6h to 4 bytes 0 */ uint8_t pad[2]; /* align ip6h to 4 bytes 0 */
#endif #endif
uint32_t vnet_len; /* 14 2 */ struct tap_hdr taph; /* 14 2 */
struct ethhdr eh; /* 18 6 */
struct ipv6hdr ip6h; /* 32 20 */ struct ipv6hdr ip6h; /* 32 20 */
struct tcphdr th /* 72 */ __attribute__ ((aligned(4))); /* 60 */ struct tcphdr th /* 72 */ __attribute__ ((aligned(4))); /* 60 */
char opts[OPT_MSS_LEN + OPT_WS_LEN + 1]; char opts[OPT_MSS_LEN + OPT_WS_LEN + 1];
@ -1013,21 +1003,10 @@ void tcp_update_l2_buf(const unsigned char *eth_d, const unsigned char *eth_s,
struct tcp4_l2_buf_t *b4 = &tcp4_l2_buf[i]; struct tcp4_l2_buf_t *b4 = &tcp4_l2_buf[i];
struct tcp6_l2_buf_t *b6 = &tcp6_l2_buf[i]; struct tcp6_l2_buf_t *b6 = &tcp6_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); tap_update_mac(&b4f->taph, eth_d, eth_s);
tap_update_mac(&b6f->taph, eth_d, eth_s);
memcpy(b4f->eh.h_dest, eth_d, ETH_ALEN);
memcpy(b6f->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);
memcpy(b4f->eh.h_source, eth_s, ETH_ALEN);
memcpy(b6f->eh.h_source, eth_s, ETH_ALEN);
}
if (ip_da) { if (ip_da) {
b4f->iph.daddr = b4->iph.daddr = ip_da->s_addr; b4f->iph.daddr = b4->iph.daddr = ip_da->s_addr;
@ -1051,15 +1030,16 @@ void tcp_update_l2_buf(const unsigned char *eth_d, const unsigned char *eth_s,
/** /**
* tcp_sock4_iov_init() - Initialise scatter-gather L2 buffers for IPv4 sockets * tcp_sock4_iov_init() - Initialise scatter-gather L2 buffers for IPv4 sockets
* @c: Execution context
*/ */
static void tcp_sock4_iov_init(void) static void tcp_sock4_iov_init(const struct ctx *c)
{ {
struct iovec *iov; struct iovec *iov;
int i; int i;
for (i = 0; i < ARRAY_SIZE(tcp4_l2_buf); i++) { for (i = 0; i < ARRAY_SIZE(tcp4_l2_buf); i++) {
tcp4_l2_buf[i] = (struct tcp4_l2_buf_t) { tcp4_l2_buf[i] = (struct tcp4_l2_buf_t) {
.eh = L2_BUF_ETH_INIT(ETH_P_IP), .taph = TAP_HDR_INIT(ETH_P_IP),
.iph = L2_BUF_IP4_INIT(IPPROTO_TCP), .iph = L2_BUF_IP4_INIT(IPPROTO_TCP),
.th = { .doff = sizeof(struct tcphdr) / 4, .ack = 1 } .th = { .doff = sizeof(struct tcphdr) / 4, .ack = 1 }
}; };
@ -1067,29 +1047,30 @@ static void tcp_sock4_iov_init(void)
for (i = 0; i < ARRAY_SIZE(tcp4_l2_flags_buf); i++) { for (i = 0; i < ARRAY_SIZE(tcp4_l2_flags_buf); i++) {
tcp4_l2_flags_buf[i] = (struct tcp4_l2_flags_buf_t) { tcp4_l2_flags_buf[i] = (struct tcp4_l2_flags_buf_t) {
.eh = L2_BUF_ETH_INIT(ETH_P_IP), .taph = TAP_HDR_INIT(ETH_P_IP),
.iph = L2_BUF_IP4_INIT(IPPROTO_TCP) .iph = L2_BUF_IP4_INIT(IPPROTO_TCP)
}; };
} }
for (i = 0, iov = tcp4_l2_iov; i < TCP_FRAMES_MEM; i++, iov++) for (i = 0, iov = tcp4_l2_iov; i < TCP_FRAMES_MEM; i++, iov++)
iov->iov_base = &tcp4_l2_buf[i].vnet_len; iov->iov_base = tap_iov_base(c, &tcp4_l2_buf[i].taph);
for (i = 0, iov = tcp4_l2_flags_iov; i < TCP_FRAMES_MEM; i++, iov++) for (i = 0, iov = tcp4_l2_flags_iov; i < TCP_FRAMES_MEM; i++, iov++)
iov->iov_base = &tcp4_l2_flags_buf[i].vnet_len; iov->iov_base = tap_iov_base(c, &tcp4_l2_flags_buf[i].taph);
} }
/** /**
* tcp_sock6_iov_init() - Initialise scatter-gather L2 buffers for IPv6 sockets * tcp_sock6_iov_init() - Initialise scatter-gather L2 buffers for IPv6 sockets
* @c: Execution context
*/ */
static void tcp_sock6_iov_init(void) static void tcp_sock6_iov_init(const struct ctx *c)
{ {
struct iovec *iov; struct iovec *iov;
int i; int i;
for (i = 0; i < ARRAY_SIZE(tcp6_l2_buf); i++) { for (i = 0; i < ARRAY_SIZE(tcp6_l2_buf); i++) {
tcp6_l2_buf[i] = (struct tcp6_l2_buf_t) { tcp6_l2_buf[i] = (struct tcp6_l2_buf_t) {
.eh = L2_BUF_ETH_INIT(ETH_P_IPV6), .taph = TAP_HDR_INIT(ETH_P_IPV6),
.ip6h = L2_BUF_IP6_INIT(IPPROTO_TCP), .ip6h = L2_BUF_IP6_INIT(IPPROTO_TCP),
.th = { .doff = sizeof(struct tcphdr) / 4, .ack = 1 } .th = { .doff = sizeof(struct tcphdr) / 4, .ack = 1 }
}; };
@ -1097,16 +1078,16 @@ static void tcp_sock6_iov_init(void)
for (i = 0; i < ARRAY_SIZE(tcp6_l2_flags_buf); i++) { for (i = 0; i < ARRAY_SIZE(tcp6_l2_flags_buf); i++) {
tcp6_l2_flags_buf[i] = (struct tcp6_l2_flags_buf_t) { tcp6_l2_flags_buf[i] = (struct tcp6_l2_flags_buf_t) {
.eh = L2_BUF_ETH_INIT(ETH_P_IPV6), .taph = TAP_HDR_INIT(ETH_P_IPV6),
.ip6h = L2_BUF_IP6_INIT(IPPROTO_TCP) .ip6h = L2_BUF_IP6_INIT(IPPROTO_TCP)
}; };
} }
for (i = 0, iov = tcp6_l2_iov; i < TCP_FRAMES_MEM; i++, iov++) for (i = 0, iov = tcp6_l2_iov; i < TCP_FRAMES_MEM; i++, iov++)
iov->iov_base = &tcp6_l2_buf[i].vnet_len; iov->iov_base = tap_iov_base(c, &tcp6_l2_buf[i].taph);
for (i = 0, iov = tcp6_l2_flags_iov; i < TCP_FRAMES_MEM; i++, iov++) for (i = 0, iov = tcp6_l2_flags_iov; i < TCP_FRAMES_MEM; i++, iov++)
iov->iov_base = &tcp6_l2_flags_buf[i].vnet_len; iov->iov_base = tap_iov_base(c, &tcp6_l2_flags_buf[i].taph);
} }
/** /**
@ -1493,10 +1474,7 @@ do { \
tcp_update_check_tcp4(b); tcp_update_check_tcp4(b);
tlen = ip_len + sizeof(struct ethhdr); tlen = tap_iov_len(c, &b->taph, ip_len);
if (c->mode == MODE_PASST)
b->vnet_len = htonl(tlen);
tlen += sizeof(b->vnet_len);
} else { } else {
struct tcp6_l2_buf_t *b = (struct tcp6_l2_buf_t *)p; struct tcp6_l2_buf_t *b = (struct tcp6_l2_buf_t *)p;
@ -1519,10 +1497,7 @@ do { \
b->ip6h.flow_lbl[1] = (conn->sock >> 8) & 0xff; b->ip6h.flow_lbl[1] = (conn->sock >> 8) & 0xff;
b->ip6h.flow_lbl[2] = (conn->sock >> 0) & 0xff; b->ip6h.flow_lbl[2] = (conn->sock >> 0) & 0xff;
tlen = ip_len + sizeof(struct ethhdr); tlen = tap_iov_len(c, &b->taph, ip_len);
if (c->mode == MODE_PASST)
b->vnet_len = htonl(tlen);
tlen += sizeof(b->vnet_len);
} }
#undef SET_TCP_HEADER_COMMON_V4_V6 #undef SET_TCP_HEADER_COMMON_V4_V6
@ -3117,10 +3092,10 @@ int tcp_init(struct ctx *c)
tcp_l2_mh[i] = (struct mmsghdr) { .msg_hdr.msg_iovlen = 1 }; tcp_l2_mh[i] = (struct mmsghdr) { .msg_hdr.msg_iovlen = 1 };
if (c->ifi4) if (c->ifi4)
tcp_sock4_iov_init(); tcp_sock4_iov_init(c);
if (c->ifi6) if (c->ifi6)
tcp_sock6_iov_init(); tcp_sock6_iov_init(c);
memset(init_sock_pool4, 0xff, sizeof(init_sock_pool4)); memset(init_sock_pool4, 0xff, sizeof(init_sock_pool4));
memset(init_sock_pool6, 0xff, sizeof(init_sock_pool6)); memset(init_sock_pool6, 0xff, sizeof(init_sock_pool6));