diff options
Diffstat (limited to 'sys/netinet/tcp_lro.c')
| -rw-r--r-- | sys/netinet/tcp_lro.c | 615 |
1 files changed, 615 insertions, 0 deletions
diff --git a/sys/netinet/tcp_lro.c b/sys/netinet/tcp_lro.c new file mode 100644 index 0000000..032d47c --- /dev/null +++ b/sys/netinet/tcp_lro.c @@ -0,0 +1,615 @@ +/*- + * Copyright (c) 2007, Myricom Inc. + * Copyright (c) 2008, Intel Corporation. + * Copyright (c) 2012 The FreeBSD Foundation + * All rights reserved. + * + * Portions of this software were developed by Bjoern Zeeb + * under sponsorship from the FreeBSD Foundation. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include "opt_inet.h" +#include "opt_inet6.h" + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/mbuf.h> +#include <sys/kernel.h> +#include <sys/socket.h> + +#include <net/if.h> +#include <net/if_var.h> +#include <net/ethernet.h> +#include <net/vnet.h> + +#include <netinet/in_systm.h> +#include <netinet/in.h> +#include <netinet/ip6.h> +#include <netinet/ip.h> +#include <netinet/ip_var.h> +#include <netinet/tcp.h> +#include <netinet/tcp_lro.h> + +#include <netinet6/ip6_var.h> + +#include <machine/in_cksum.h> + +#ifndef LRO_ENTRIES +#define LRO_ENTRIES 8 /* # of LRO entries per RX queue. */ +#endif + +#define TCP_LRO_UPDATE_CSUM 1 +#ifndef TCP_LRO_UPDATE_CSUM +#define TCP_LRO_INVALID_CSUM 0x0000 +#endif + +int +tcp_lro_init(struct lro_ctrl *lc) +{ + struct lro_entry *le; + int error, i; + + lc->lro_bad_csum = 0; + lc->lro_queued = 0; + lc->lro_flushed = 0; + lc->lro_cnt = 0; + SLIST_INIT(&lc->lro_free); + SLIST_INIT(&lc->lro_active); + + error = 0; + for (i = 0; i < LRO_ENTRIES; i++) { + le = (struct lro_entry *)malloc(sizeof(*le), M_DEVBUF, + M_NOWAIT | M_ZERO); + if (le == NULL) { + if (i == 0) + error = ENOMEM; + break; + } + lc->lro_cnt = i + 1; + SLIST_INSERT_HEAD(&lc->lro_free, le, next); + } + + return (error); +} + +void +tcp_lro_free(struct lro_ctrl *lc) +{ + struct lro_entry *le; + + while (!SLIST_EMPTY(&lc->lro_free)) { + le = SLIST_FIRST(&lc->lro_free); + SLIST_REMOVE_HEAD(&lc->lro_free, next); + free(le, M_DEVBUF); + } +} + +#ifdef TCP_LRO_UPDATE_CSUM +static uint16_t +tcp_lro_csum_th(struct tcphdr *th) +{ + uint32_t ch; + uint16_t *p, l; + + ch = th->th_sum = 0x0000; + l = th->th_off; + p = (uint16_t *)th; + while (l > 0) { + ch += *p; + p++; + ch += *p; + p++; + l--; + } + while (ch > 0xffff) + ch = (ch >> 16) + (ch & 0xffff); + + return (ch & 0xffff); +} + +static uint16_t +tcp_lro_rx_csum_fixup(struct lro_entry *le, void *l3hdr, struct tcphdr *th, + uint16_t tcp_data_len, uint16_t csum) +{ + uint32_t c; + uint16_t cs; + + c = csum; + + /* Remove length from checksum. */ + switch (le->eh_type) { +#ifdef INET6 + case ETHERTYPE_IPV6: + { + struct ip6_hdr *ip6; + + ip6 = (struct ip6_hdr *)l3hdr; + if (le->append_cnt == 0) + cs = ip6->ip6_plen; + else { + uint32_t cx; + + cx = ntohs(ip6->ip6_plen); + cs = in6_cksum_pseudo(ip6, cx, ip6->ip6_nxt, 0); + } + break; + } +#endif +#ifdef INET + case ETHERTYPE_IP: + { + struct ip *ip4; + + ip4 = (struct ip *)l3hdr; + if (le->append_cnt == 0) + cs = ip4->ip_len; + else { + cs = in_addword(ntohs(ip4->ip_len) - sizeof(*ip4), + IPPROTO_TCP); + cs = in_pseudo(ip4->ip_src.s_addr, ip4->ip_dst.s_addr, + htons(cs)); + } + break; + } +#endif + default: + cs = 0; /* Keep compiler happy. */ + } + + cs = ~cs; + c += cs; + + /* Remove TCP header csum. */ + cs = ~tcp_lro_csum_th(th); + c += cs; + while (c > 0xffff) + c = (c >> 16) + (c & 0xffff); + + return (c & 0xffff); +} +#endif + +void +tcp_lro_flush(struct lro_ctrl *lc, struct lro_entry *le) +{ + + if (le->append_cnt > 0) { + struct tcphdr *th; + uint16_t p_len; + + p_len = htons(le->p_len); + switch (le->eh_type) { +#ifdef INET6 + case ETHERTYPE_IPV6: + { + struct ip6_hdr *ip6; + + ip6 = le->le_ip6; + ip6->ip6_plen = p_len; + th = (struct tcphdr *)(ip6 + 1); + le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID | + CSUM_PSEUDO_HDR; + le->p_len += ETHER_HDR_LEN + sizeof(*ip6); + break; + } +#endif +#ifdef INET + case ETHERTYPE_IP: + { + struct ip *ip4; +#ifdef TCP_LRO_UPDATE_CSUM + uint32_t cl; + uint16_t c; +#endif + + ip4 = le->le_ip4; +#ifdef TCP_LRO_UPDATE_CSUM + /* Fix IP header checksum for new length. */ + c = ~ip4->ip_sum; + cl = c; + c = ~ip4->ip_len; + cl += c + p_len; + while (cl > 0xffff) + cl = (cl >> 16) + (cl & 0xffff); + c = cl; + ip4->ip_sum = ~c; +#else + ip4->ip_sum = TCP_LRO_INVALID_CSUM; +#endif + ip4->ip_len = p_len; + th = (struct tcphdr *)(ip4 + 1); + le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID | + CSUM_PSEUDO_HDR | CSUM_IP_CHECKED | CSUM_IP_VALID; + le->p_len += ETHER_HDR_LEN; + break; + } +#endif + default: + th = NULL; /* Keep compiler happy. */ + } + le->m_head->m_pkthdr.csum_data = 0xffff; + le->m_head->m_pkthdr.len = le->p_len; + + /* Incorporate the latest ACK into the TCP header. */ + th->th_ack = le->ack_seq; + th->th_win = le->window; + /* Incorporate latest timestamp into the TCP header. */ + if (le->timestamp != 0) { + uint32_t *ts_ptr; + + ts_ptr = (uint32_t *)(th + 1); + ts_ptr[1] = htonl(le->tsval); + ts_ptr[2] = le->tsecr; + } +#ifdef TCP_LRO_UPDATE_CSUM + /* Update the TCP header checksum. */ + le->ulp_csum += p_len; + le->ulp_csum += tcp_lro_csum_th(th); + while (le->ulp_csum > 0xffff) + le->ulp_csum = (le->ulp_csum >> 16) + + (le->ulp_csum & 0xffff); + th->th_sum = (le->ulp_csum & 0xffff); + th->th_sum = ~th->th_sum; +#else + th->th_sum = TCP_LRO_INVALID_CSUM; +#endif + } + + (*lc->ifp->if_input)(lc->ifp, le->m_head); + lc->lro_queued += le->append_cnt + 1; + lc->lro_flushed++; + bzero(le, sizeof(*le)); + SLIST_INSERT_HEAD(&lc->lro_free, le, next); +} + +#ifdef INET6 +static int +tcp_lro_rx_ipv6(struct lro_ctrl *lc, struct mbuf *m, struct ip6_hdr *ip6, + struct tcphdr **th) +{ + + /* XXX-BZ we should check the flow-label. */ + + /* XXX-BZ We do not yet support ext. hdrs. */ + if (ip6->ip6_nxt != IPPROTO_TCP) + return (TCP_LRO_NOT_SUPPORTED); + + /* Find the TCP header. */ + *th = (struct tcphdr *)(ip6 + 1); + + return (0); +} +#endif + +#ifdef INET +static int +tcp_lro_rx_ipv4(struct lro_ctrl *lc, struct mbuf *m, struct ip *ip4, + struct tcphdr **th) +{ + int csum_flags; + uint16_t csum; + + if (ip4->ip_p != IPPROTO_TCP) + return (TCP_LRO_NOT_SUPPORTED); + + /* Ensure there are no options. */ + if ((ip4->ip_hl << 2) != sizeof (*ip4)) + return (TCP_LRO_CANNOT); + + /* .. and the packet is not fragmented. */ + if (ip4->ip_off & htons(IP_MF|IP_OFFMASK)) + return (TCP_LRO_CANNOT); + + /* Legacy IP has a header checksum that needs to be correct. */ + csum_flags = m->m_pkthdr.csum_flags; + if (csum_flags & CSUM_IP_CHECKED) { + if (__predict_false((csum_flags & CSUM_IP_VALID) == 0)) { + lc->lro_bad_csum++; + return (TCP_LRO_CANNOT); + } + } else { + csum = in_cksum_hdr(ip4); + if (__predict_false((csum) != 0)) { + lc->lro_bad_csum++; + return (TCP_LRO_CANNOT); + } + } + + /* Find the TCP header (we assured there are no IP options). */ + *th = (struct tcphdr *)(ip4 + 1); + + return (0); +} +#endif + +int +tcp_lro_rx(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum) +{ + struct lro_entry *le; + struct ether_header *eh; +#ifdef INET6 + struct ip6_hdr *ip6 = NULL; /* Keep compiler happy. */ +#endif +#ifdef INET + struct ip *ip4 = NULL; /* Keep compiler happy. */ +#endif + struct tcphdr *th; + void *l3hdr = NULL; /* Keep compiler happy. */ + uint32_t *ts_ptr; + tcp_seq seq; + int error, ip_len, l; + uint16_t eh_type, tcp_data_len; + + /* We expect a contiguous header [eh, ip, tcp]. */ + + eh = mtod(m, struct ether_header *); + eh_type = ntohs(eh->ether_type); + switch (eh_type) { +#ifdef INET6 + case ETHERTYPE_IPV6: + { + CURVNET_SET(lc->ifp->if_vnet); + if (V_ip6_forwarding != 0) { + /* XXX-BZ stats but changing lro_ctrl is a problem. */ + CURVNET_RESTORE(); + return (TCP_LRO_CANNOT); + } + CURVNET_RESTORE(); + l3hdr = ip6 = (struct ip6_hdr *)(eh + 1); + error = tcp_lro_rx_ipv6(lc, m, ip6, &th); + if (error != 0) + return (error); + tcp_data_len = ntohs(ip6->ip6_plen); + ip_len = sizeof(*ip6) + tcp_data_len; + break; + } +#endif +#ifdef INET + case ETHERTYPE_IP: + { + CURVNET_SET(lc->ifp->if_vnet); + if (V_ipforwarding != 0) { + /* XXX-BZ stats but changing lro_ctrl is a problem. */ + CURVNET_RESTORE(); + return (TCP_LRO_CANNOT); + } + CURVNET_RESTORE(); + l3hdr = ip4 = (struct ip *)(eh + 1); + error = tcp_lro_rx_ipv4(lc, m, ip4, &th); + if (error != 0) + return (error); + ip_len = ntohs(ip4->ip_len); + tcp_data_len = ip_len - sizeof(*ip4); + break; + } +#endif + /* XXX-BZ what happens in case of VLAN(s)? */ + default: + return (TCP_LRO_NOT_SUPPORTED); + } + + /* + * If the frame is padded beyond the end of the IP packet, then we must + * trim the extra bytes off. + */ + l = m->m_pkthdr.len - (ETHER_HDR_LEN + ip_len); + if (l != 0) { + if (l < 0) + /* Truncated packet. */ + return (TCP_LRO_CANNOT); + + m_adj(m, -l); + } + + /* + * Check TCP header constraints. + */ + /* Ensure no bits set besides ACK or PSH. */ + if ((th->th_flags & ~(TH_ACK | TH_PUSH)) != 0) + return (TCP_LRO_CANNOT); + + /* XXX-BZ We lose a AKC|PUSH flag concatinating multiple segments. */ + /* XXX-BZ Ideally we'd flush on PUSH? */ + + /* + * Check for timestamps. + * Since the only option we handle are timestamps, we only have to + * handle the simple case of aligned timestamps. + */ + l = (th->th_off << 2); + tcp_data_len -= l; + l -= sizeof(*th); + ts_ptr = (uint32_t *)(th + 1); + if (l != 0 && (__predict_false(l != TCPOLEN_TSTAMP_APPA) || + (*ts_ptr != ntohl(TCPOPT_NOP<<24|TCPOPT_NOP<<16| + TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)))) + return (TCP_LRO_CANNOT); + + /* If the driver did not pass in the checksum, set it now. */ + if (csum == 0x0000) + csum = th->th_sum; + + seq = ntohl(th->th_seq); + + /* Try to find a matching previous segment. */ + SLIST_FOREACH(le, &lc->lro_active, next) { + if (le->eh_type != eh_type) + continue; + if (le->source_port != th->th_sport || + le->dest_port != th->th_dport) + continue; + switch (eh_type) { +#ifdef INET6 + case ETHERTYPE_IPV6: + if (bcmp(&le->source_ip6, &ip6->ip6_src, + sizeof(struct in6_addr)) != 0 || + bcmp(&le->dest_ip6, &ip6->ip6_dst, + sizeof(struct in6_addr)) != 0) + continue; + break; +#endif +#ifdef INET + case ETHERTYPE_IP: + if (le->source_ip4 != ip4->ip_src.s_addr || + le->dest_ip4 != ip4->ip_dst.s_addr) + continue; + break; +#endif + } + + /* Flush now if appending will result in overflow. */ + if (le->p_len > (65535 - tcp_data_len)) { + SLIST_REMOVE(&lc->lro_active, le, lro_entry, next); + tcp_lro_flush(lc, le); + break; + } + + /* Try to append the new segment. */ + if (__predict_false(seq != le->next_seq || + (tcp_data_len == 0 && le->ack_seq == th->th_ack))) { + /* Out of order packet or duplicate ACK. */ + SLIST_REMOVE(&lc->lro_active, le, lro_entry, next); + tcp_lro_flush(lc, le); + return (TCP_LRO_CANNOT); + } + + if (l != 0) { + uint32_t tsval = ntohl(*(ts_ptr + 1)); + /* Make sure timestamp values are increasing. */ + /* XXX-BZ flip and use TSTMP_GEQ macro for this? */ + if (__predict_false(le->tsval > tsval || + *(ts_ptr + 2) == 0)) + return (TCP_LRO_CANNOT); + le->tsval = tsval; + le->tsecr = *(ts_ptr + 2); + } + + le->next_seq += tcp_data_len; + le->ack_seq = th->th_ack; + le->window = th->th_win; + le->append_cnt++; + +#ifdef TCP_LRO_UPDATE_CSUM + le->ulp_csum += tcp_lro_rx_csum_fixup(le, l3hdr, th, + tcp_data_len, ~csum); +#endif + + if (tcp_data_len == 0) { + m_freem(m); + return (0); + } + + le->p_len += tcp_data_len; + + /* + * Adjust the mbuf so that m_data points to the first byte of + * the ULP payload. Adjust the mbuf to avoid complications and + * append new segment to existing mbuf chain. + */ + m_adj(m, m->m_pkthdr.len - tcp_data_len); + m->m_flags &= ~M_PKTHDR; + + le->m_tail->m_next = m; + le->m_tail = m_last(m); + + /* + * If a possible next full length packet would cause an + * overflow, pro-actively flush now. + */ + if (le->p_len > (65535 - lc->ifp->if_mtu)) { + SLIST_REMOVE(&lc->lro_active, le, lro_entry, next); + tcp_lro_flush(lc, le); + } + + return (0); + } + + /* Try to find an empty slot. */ + if (SLIST_EMPTY(&lc->lro_free)) + return (TCP_LRO_CANNOT); + + /* Start a new segment chain. */ + le = SLIST_FIRST(&lc->lro_free); + SLIST_REMOVE_HEAD(&lc->lro_free, next); + SLIST_INSERT_HEAD(&lc->lro_active, le, next); + + /* Start filling in details. */ + switch (eh_type) { +#ifdef INET6 + case ETHERTYPE_IPV6: + le->le_ip6 = ip6; + le->source_ip6 = ip6->ip6_src; + le->dest_ip6 = ip6->ip6_dst; + le->eh_type = eh_type; + le->p_len = m->m_pkthdr.len - ETHER_HDR_LEN - sizeof(*ip6); + break; +#endif +#ifdef INET + case ETHERTYPE_IP: + le->le_ip4 = ip4; + le->source_ip4 = ip4->ip_src.s_addr; + le->dest_ip4 = ip4->ip_dst.s_addr; + le->eh_type = eh_type; + le->p_len = m->m_pkthdr.len - ETHER_HDR_LEN; + break; +#endif + } + le->source_port = th->th_sport; + le->dest_port = th->th_dport; + + le->next_seq = seq + tcp_data_len; + le->ack_seq = th->th_ack; + le->window = th->th_win; + if (l != 0) { + le->timestamp = 1; + le->tsval = ntohl(*(ts_ptr + 1)); + le->tsecr = *(ts_ptr + 2); + } + +#ifdef TCP_LRO_UPDATE_CSUM + /* + * Do not touch the csum of the first packet. However save the + * "adjusted" checksum of just the source and destination addresses, + * the next header and the TCP payload. The length and TCP header + * parts may change, so we remove those from the saved checksum and + * re-add with final values on tcp_lro_flush() if needed. + */ + KASSERT(le->ulp_csum == 0, ("%s: le=%p le->ulp_csum=0x%04x\n", + __func__, le, le->ulp_csum)); + + le->ulp_csum = tcp_lro_rx_csum_fixup(le, l3hdr, th, tcp_data_len, + ~csum); + th->th_sum = csum; /* Restore checksum on first packet. */ +#endif + + le->m_head = m; + le->m_tail = m_last(m); + + return (0); +} + +/* end */ |
