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tcp: move buffers management functions to their own file
Move all the TCP parts using internal buffers to tcp_buf.c and keep generic TCP management functions in tcp.c. Add tcp_internal.h to export needed functions from tcp.c and tcp_buf.h from tcp_buf.c With this change we can use existing TCP functions with a different kind of memory storage as for instance the shared memory provided by the guest via vhost-user. Signed-off-by: Laurent Vivier <lvivier@redhat.com> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
Laurent Vivier
Stefano Brivio
parent
ec26fa013a
commit
fba2b544b6
5
Makefile
5
Makefile
@ -47,7 +47,7 @@ FLAGS += -DDUAL_STACK_SOCKETS=$(DUAL_STACK_SOCKETS)
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PASST_SRCS = arch.c arp.c checksum.c conf.c dhcp.c dhcpv6.c flow.c fwd.c \
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icmp.c igmp.c inany.c iov.c ip.c isolation.c lineread.c log.c mld.c \
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ndp.c netlink.c packet.c passt.c pasta.c pcap.c pif.c tap.c tcp.c \
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tcp_splice.c udp.c util.c
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tcp_buf.c tcp_splice.c udp.c util.c
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QRAP_SRCS = qrap.c
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SRCS = $(PASST_SRCS) $(QRAP_SRCS)
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@ -56,7 +56,8 @@ MANPAGES = passt.1 pasta.1 qrap.1
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PASST_HEADERS = arch.h arp.h checksum.h conf.h dhcp.h dhcpv6.h flow.h fwd.h \
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flow_table.h icmp.h icmp_flow.h inany.h iov.h ip.h isolation.h \
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lineread.h log.h ndp.h netlink.h packet.h passt.h pasta.h pcap.h pif.h \
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siphash.h tap.h tcp.h tcp_conn.h tcp_splice.h udp.h util.h
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siphash.h tap.h tcp.h tcp_buf.h tcp_conn.h tcp_internal.h tcp_splice.h \
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udp.h util.h
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HEADERS = $(PASST_HEADERS) seccomp.h
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C := \#include <linux/tcp.h>\nstruct tcp_info x = { .tcpi_snd_wnd = 0 };
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552
tcp.c
552
tcp.c
@ -302,28 +302,14 @@
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#include "flow.h"
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#include "flow_table.h"
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#define TCP_FRAMES_MEM 128
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#define TCP_FRAMES \
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(c->mode == MODE_PASST ? TCP_FRAMES_MEM : 1)
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#include "tcp_internal.h"
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#include "tcp_buf.h"
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#define TCP_HASH_TABLE_LOAD 70 /* % */
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#define TCP_HASH_TABLE_SIZE (FLOW_MAX * 100 / TCP_HASH_TABLE_LOAD)
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#define MAX_WS 8
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#define MAX_WINDOW (1 << (16 + (MAX_WS)))
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/* MSS rounding: see SET_MSS() */
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#define MSS_DEFAULT 536
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#define MSS4 ROUND_DOWN(IP_MAX_MTU - \
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sizeof(struct tcphdr) - \
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sizeof(struct iphdr), \
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sizeof(uint32_t))
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#define MSS6 ROUND_DOWN(IP_MAX_MTU - \
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sizeof(struct tcphdr) - \
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sizeof(struct ipv6hdr), \
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sizeof(uint32_t))
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#define WINDOW_DEFAULT 14600 /* RFC 6928 */
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#ifdef HAS_SND_WND
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# define KERNEL_REPORTS_SND_WND(c) ((c)->tcp.kernel_snd_wnd)
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@ -345,33 +331,10 @@
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*/
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#define SOL_TCP IPPROTO_TCP
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#define SEQ_LE(a, b) ((b) - (a) < MAX_WINDOW)
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#define SEQ_LT(a, b) ((b) - (a) - 1 < MAX_WINDOW)
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#define SEQ_GE(a, b) ((a) - (b) < MAX_WINDOW)
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#define SEQ_GT(a, b) ((a) - (b) - 1 < MAX_WINDOW)
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#define FIN (1 << 0)
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#define SYN (1 << 1)
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#define RST (1 << 2)
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#define ACK (1 << 4)
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/* Flags for internal usage */
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#define DUP_ACK (1 << 5)
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#define ACK_IF_NEEDED 0 /* See tcp_send_flag() */
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#define OPT_EOL 0
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#define OPT_NOP 1
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#define OPT_MSS 2
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#define OPT_MSS_LEN 4
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#define OPT_WS 3
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#define OPT_WS_LEN 3
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#define OPT_SACKP 4
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#define OPT_SACK 5
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#define OPT_TS 8
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#define TAPSIDE(conn_) ((conn_)->f.pif[1] == PIF_TAP)
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#define CONN_V4(conn) (!!inany_v4(&(conn)->faddr))
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#define CONN_V6(conn) (!CONN_V4(conn))
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#define CONN_IS_CLOSING(conn) \
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(((conn)->events & ESTABLISHED) && \
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((conn)->events & (SOCK_FIN_RCVD | TAP_FIN_RCVD)))
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@ -408,106 +371,7 @@ static int tcp_sock_ns [NUM_PORTS][IP_VERSIONS];
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*/
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static union inany_addr low_rtt_dst[LOW_RTT_TABLE_SIZE];
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/* Static buffers */
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/**
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* struct tcp_payload_t - TCP header and data to send segments with payload
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* @th: TCP header
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* @data: TCP data
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*/
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struct tcp_payload_t {
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struct tcphdr th;
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uint8_t data[IP_MAX_MTU - sizeof(struct tcphdr)];
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#ifdef __AVX2__
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} __attribute__ ((packed, aligned(32))); /* For AVX2 checksum routines */
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#else
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} __attribute__ ((packed, aligned(__alignof__(unsigned int))));
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#endif
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/**
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* struct tcp_flags_t - TCP header and data to send zero-length
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* segments (flags)
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* @th: TCP header
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* @opts TCP options
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*/
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struct tcp_flags_t {
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struct tcphdr th;
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char opts[OPT_MSS_LEN + OPT_WS_LEN + 1];
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#ifdef __AVX2__
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} __attribute__ ((packed, aligned(32)));
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#else
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} __attribute__ ((packed, aligned(__alignof__(unsigned int))));
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#endif
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/* Ethernet header for IPv4 frames */
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static struct ethhdr tcp4_eth_src;
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static struct tap_hdr tcp4_payload_tap_hdr[TCP_FRAMES_MEM];
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/* IPv4 headers */
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static struct iphdr tcp4_payload_ip[TCP_FRAMES_MEM];
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/* TCP segments with payload for IPv4 frames */
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static struct tcp_payload_t tcp4_payload[TCP_FRAMES_MEM];
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static_assert(MSS4 <= sizeof(tcp4_payload[0].data), "MSS4 is greater than 65516");
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/* References tracking the owner connection of frames in the tap outqueue */
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static struct tcp_tap_conn *tcp4_frame_conns[TCP_FRAMES_MEM];
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static unsigned int tcp4_payload_used;
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static struct tap_hdr tcp4_flags_tap_hdr[TCP_FRAMES_MEM];
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/* IPv4 headers for TCP segment without payload */
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static struct iphdr tcp4_flags_ip[TCP_FRAMES_MEM];
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/* TCP segments without payload for IPv4 frames */
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static struct tcp_flags_t tcp4_flags[TCP_FRAMES_MEM];
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static unsigned int tcp4_flags_used;
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/* Ethernet header for IPv6 frames */
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static struct ethhdr tcp6_eth_src;
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static struct tap_hdr tcp6_payload_tap_hdr[TCP_FRAMES_MEM];
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/* IPv6 headers */
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static struct ipv6hdr tcp6_payload_ip[TCP_FRAMES_MEM];
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/* TCP headers and data for IPv6 frames */
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static struct tcp_payload_t tcp6_payload[TCP_FRAMES_MEM];
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static_assert(MSS6 <= sizeof(tcp6_payload[0].data), "MSS6 is greater than 65516");
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/* References tracking the owner connection of frames in the tap outqueue */
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static struct tcp_tap_conn *tcp6_frame_conns[TCP_FRAMES_MEM];
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static unsigned int tcp6_payload_used;
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static struct tap_hdr tcp6_flags_tap_hdr[TCP_FRAMES_MEM];
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/* IPv6 headers for TCP segment without payload */
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static struct ipv6hdr tcp6_flags_ip[TCP_FRAMES_MEM];
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/* TCP segment without payload for IPv6 frames */
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static struct tcp_flags_t tcp6_flags[TCP_FRAMES_MEM];
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static unsigned int tcp6_flags_used;
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/* recvmsg()/sendmsg() data for tap */
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static char tcp_buf_discard [MAX_WINDOW];
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static struct iovec iov_sock [TCP_FRAMES_MEM + 1];
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/*
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* enum tcp_iov_parts - I/O vector parts for one TCP frame
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* @TCP_IOV_TAP tap backend specific header
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* @TCP_IOV_ETH Ethernet header
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* @TCP_IOV_IP IP (v4/v6) header
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* @TCP_IOV_PAYLOAD IP payload (TCP header + data)
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* @TCP_NUM_IOVS the number of entries in the iovec array
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*/
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enum tcp_iov_parts {
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TCP_IOV_TAP = 0,
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TCP_IOV_ETH = 1,
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TCP_IOV_IP = 2,
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TCP_IOV_PAYLOAD = 3,
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TCP_NUM_IOVS
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};
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static struct iovec tcp4_l2_iov [TCP_FRAMES_MEM][TCP_NUM_IOVS];
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static struct iovec tcp6_l2_iov [TCP_FRAMES_MEM][TCP_NUM_IOVS];
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static struct iovec tcp4_l2_flags_iov [TCP_FRAMES_MEM][TCP_NUM_IOVS];
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static struct iovec tcp6_l2_flags_iov [TCP_FRAMES_MEM][TCP_NUM_IOVS];
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char tcp_buf_discard [MAX_WINDOW];
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/* sendmsg() to socket */
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static struct iovec tcp_iov [UIO_MAXIOV];
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@ -552,14 +416,6 @@ static uint32_t tcp_conn_epoll_events(uint8_t events, uint8_t conn_flags)
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return EPOLLRDHUP;
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}
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static void conn_flag_do(const struct ctx *c, struct tcp_tap_conn *conn,
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unsigned long flag);
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#define conn_flag(c, conn, flag) \
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do { \
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flow_trace(conn, "flag at %s:%i", __func__, __LINE__); \
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conn_flag_do(c, conn, flag); \
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} while (0)
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/**
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* tcp_epoll_ctl() - Add/modify/delete epoll state from connection events
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* @c: Execution context
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@ -671,7 +527,7 @@ static void tcp_timer_ctl(const struct ctx *c, struct tcp_tap_conn *conn)
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* @conn: Connection pointer
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* @flag: Flag to set, or ~flag to unset
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*/
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static void conn_flag_do(const struct ctx *c, struct tcp_tap_conn *conn,
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void conn_flag_do(const struct ctx *c, struct tcp_tap_conn *conn,
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unsigned long flag)
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{
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if (flag & (flag - 1)) {
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@ -722,7 +578,7 @@ static void tcp_hash_remove(const struct ctx *c,
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* @conn: Connection pointer
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* @event: Connection event
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*/
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static void conn_event_do(const struct ctx *c, struct tcp_tap_conn *conn,
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void conn_event_do(const struct ctx *c, struct tcp_tap_conn *conn,
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unsigned long event)
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{
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int prev, new, num = fls(event);
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@ -771,12 +627,6 @@ static void conn_event_do(const struct ctx *c, struct tcp_tap_conn *conn,
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tcp_timer_ctl(c, conn);
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}
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#define conn_event(c, conn, event) \
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do { \
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flow_trace(conn, "event at %s:%i", __func__, __LINE__); \
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conn_event_do(c, conn, event); \
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} while (0)
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/**
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* tcp_rtt_dst_low() - Check if low RTT was seen for connection endpoint
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* @conn: Connection pointer
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@ -906,104 +756,6 @@ static void tcp_update_check_tcp6(struct ipv6hdr *ip6h, struct tcphdr *th)
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th->check = csum(th, l4len, sum);
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}
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/**
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* tcp_update_l2_buf() - Update Ethernet header buffers with addresses
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* @eth_d: Ethernet destination address, NULL if unchanged
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* @eth_s: Ethernet source address, NULL if unchanged
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*/
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void tcp_update_l2_buf(const unsigned char *eth_d, const unsigned char *eth_s)
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{
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eth_update_mac(&tcp4_eth_src, eth_d, eth_s);
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eth_update_mac(&tcp6_eth_src, eth_d, eth_s);
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}
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/**
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* tcp_sock4_iov_init() - Initialise scatter-gather L2 buffers for IPv4 sockets
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* @c: Execution context
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*/
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static void tcp_sock4_iov_init(const struct ctx *c)
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{
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struct iphdr iph = L2_BUF_IP4_INIT(IPPROTO_TCP);
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struct iovec *iov;
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int i;
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tcp4_eth_src.h_proto = htons_constant(ETH_P_IP);
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for (i = 0; i < ARRAY_SIZE(tcp4_payload); i++) {
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tcp4_payload_ip[i] = iph;
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tcp4_payload[i].th.doff = sizeof(struct tcphdr) / 4;
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tcp4_payload[i].th.ack = 1;
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}
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for (i = 0; i < ARRAY_SIZE(tcp4_flags); i++) {
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tcp4_flags_ip[i] = iph;
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tcp4_flags[i].th.doff = sizeof(struct tcphdr) / 4;
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tcp4_flags[i].th.ack = 1;
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}
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for (i = 0; i < TCP_FRAMES_MEM; i++) {
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iov = tcp4_l2_iov[i];
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iov[TCP_IOV_TAP] = tap_hdr_iov(c, &tcp4_payload_tap_hdr[i]);
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iov[TCP_IOV_ETH] = IOV_OF_LVALUE(tcp4_eth_src);
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iov[TCP_IOV_IP] = IOV_OF_LVALUE(tcp4_payload_ip[i]);
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iov[TCP_IOV_PAYLOAD].iov_base = &tcp4_payload[i];
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}
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for (i = 0; i < TCP_FRAMES_MEM; i++) {
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iov = tcp4_l2_flags_iov[i];
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iov[TCP_IOV_TAP] = tap_hdr_iov(c, &tcp4_flags_tap_hdr[i]);
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iov[TCP_IOV_ETH].iov_base = &tcp4_eth_src;
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iov[TCP_IOV_ETH] = IOV_OF_LVALUE(tcp4_eth_src);
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iov[TCP_IOV_IP] = IOV_OF_LVALUE(tcp4_flags_ip[i]);
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iov[TCP_IOV_PAYLOAD].iov_base = &tcp4_flags[i];
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}
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}
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/**
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* tcp_sock6_iov_init() - Initialise scatter-gather L2 buffers for IPv6 sockets
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* @c: Execution context
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*/
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static void tcp_sock6_iov_init(const struct ctx *c)
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{
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struct ipv6hdr ip6 = L2_BUF_IP6_INIT(IPPROTO_TCP);
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struct iovec *iov;
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int i;
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tcp6_eth_src.h_proto = htons_constant(ETH_P_IPV6);
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for (i = 0; i < ARRAY_SIZE(tcp6_payload); i++) {
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tcp6_payload_ip[i] = ip6;
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tcp6_payload[i].th.doff = sizeof(struct tcphdr) / 4;
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tcp6_payload[i].th.ack = 1;
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}
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for (i = 0; i < ARRAY_SIZE(tcp6_flags); i++) {
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tcp6_flags_ip[i] = ip6;
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tcp6_flags[i].th.doff = sizeof(struct tcphdr) / 4;
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tcp6_flags[i].th .ack = 1;
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}
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for (i = 0; i < TCP_FRAMES_MEM; i++) {
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iov = tcp6_l2_iov[i];
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iov[TCP_IOV_TAP] = tap_hdr_iov(c, &tcp6_payload_tap_hdr[i]);
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iov[TCP_IOV_ETH] = IOV_OF_LVALUE(tcp6_eth_src);
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iov[TCP_IOV_IP] = IOV_OF_LVALUE(tcp6_payload_ip[i]);
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iov[TCP_IOV_PAYLOAD].iov_base = &tcp6_payload[i];
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}
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for (i = 0; i < TCP_FRAMES_MEM; i++) {
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iov = tcp6_l2_flags_iov[i];
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iov[TCP_IOV_TAP] = tap_hdr_iov(c, &tcp6_flags_tap_hdr[i]);
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iov[TCP_IOV_ETH] = IOV_OF_LVALUE(tcp6_eth_src);
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iov[TCP_IOV_IP] = IOV_OF_LVALUE(tcp6_flags_ip[i]);
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iov[TCP_IOV_PAYLOAD].iov_base = &tcp6_flags[i];
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}
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}
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/**
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* tcp_opt_get() - Get option, and value if any, from TCP header
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* @opts: Pointer to start of TCP options in header
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@ -1227,76 +979,6 @@ bool tcp_flow_defer(const struct tcp_tap_conn *conn)
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return true;
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}
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static void tcp_rst_do(struct ctx *c, struct tcp_tap_conn *conn);
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#define tcp_rst(c, conn) \
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do { \
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flow_dbg((conn), "TCP reset at %s:%i", __func__, __LINE__); \
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tcp_rst_do(c, conn); \
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} while (0)
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/**
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* tcp_flags_flush() - Send out buffers for segments with no data (flags)
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* @c: Execution context
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*/
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static void tcp_flags_flush(const struct ctx *c)
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{
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tap_send_frames(c, &tcp6_l2_flags_iov[0][0], TCP_NUM_IOVS,
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tcp6_flags_used);
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tcp6_flags_used = 0;
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tap_send_frames(c, &tcp4_l2_flags_iov[0][0], TCP_NUM_IOVS,
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tcp4_flags_used);
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tcp4_flags_used = 0;
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}
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/**
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* tcp_revert_seq() - Revert affected conn->seq_to_tap after failed transmission
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* @conns: Array of connection pointers corresponding to queued frames
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* @frames: Two-dimensional array containing queued frames with sub-iovs
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* @num_frames: Number of entries in the two arrays to be compared
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*/
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static void tcp_revert_seq(struct tcp_tap_conn **conns, struct iovec (*frames)[TCP_NUM_IOVS],
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int num_frames)
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{
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int i;
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for (i = 0; i < num_frames; i++) {
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const struct tcphdr *th = frames[i][TCP_IOV_PAYLOAD].iov_base;
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struct tcp_tap_conn *conn = conns[i];
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uint32_t seq = ntohl(th->seq);
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if (SEQ_LE(conn->seq_to_tap, seq))
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continue;
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conn->seq_to_tap = seq;
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}
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}
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||||
|
||||
/**
|
||||
* tcp_payload_flush() - Send out buffers for segments with data
|
||||
* @c: Execution context
|
||||
*/
|
||||
static void tcp_payload_flush(const struct ctx *c)
|
||||
{
|
||||
size_t m;
|
||||
|
||||
m = tap_send_frames(c, &tcp6_l2_iov[0][0], TCP_NUM_IOVS,
|
||||
tcp6_payload_used);
|
||||
if (m != tcp6_payload_used) {
|
||||
tcp_revert_seq(&tcp6_frame_conns[m], &tcp6_l2_iov[m],
|
||||
tcp6_payload_used - m);
|
||||
}
|
||||
tcp6_payload_used = 0;
|
||||
|
||||
m = tap_send_frames(c, &tcp4_l2_iov[0][0], TCP_NUM_IOVS,
|
||||
tcp4_payload_used);
|
||||
if (m != tcp4_payload_used) {
|
||||
tcp_revert_seq(&tcp4_frame_conns[m], &tcp4_l2_iov[m],
|
||||
tcp4_payload_used - m);
|
||||
}
|
||||
tcp4_payload_used = 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* tcp_defer_handler() - Handler for TCP deferred tasks
|
||||
* @c: Execution context
|
||||
@ -1430,7 +1112,7 @@ static size_t tcp_fill_headers6(const struct ctx *c,
|
||||
*
|
||||
* Return: IP payload length, host order
|
||||
*/
|
||||
static size_t tcp_l2_buf_fill_headers(const struct ctx *c,
|
||||
size_t tcp_l2_buf_fill_headers(const struct ctx *c,
|
||||
const struct tcp_tap_conn *conn,
|
||||
struct iovec *iov, size_t dlen,
|
||||
const uint16_t *check, uint32_t seq)
|
||||
@ -1459,7 +1141,7 @@ static size_t tcp_l2_buf_fill_headers(const struct ctx *c,
|
||||
*
|
||||
* Return: 1 if sequence or window were updated, 0 otherwise
|
||||
*/
|
||||
static int tcp_update_seqack_wnd(const struct ctx *c, struct tcp_tap_conn *conn,
|
||||
int tcp_update_seqack_wnd(const struct ctx *c, struct tcp_tap_conn *conn,
|
||||
int force_seq, struct tcp_info *tinfo)
|
||||
{
|
||||
uint32_t prev_wnd_to_tap = conn->wnd_to_tap << conn->ws_to_tap;
|
||||
@ -1579,7 +1261,7 @@ static void tcp_update_seqack_from_tap(const struct ctx *c,
|
||||
* 0 if there is no flag to send
|
||||
* 1 otherwise
|
||||
*/
|
||||
static int tcp_prepare_flags(struct ctx *c, struct tcp_tap_conn *conn,
|
||||
int tcp_prepare_flags(struct ctx *c, struct tcp_tap_conn *conn,
|
||||
int flags, struct tcphdr *th, char *data,
|
||||
size_t *optlen)
|
||||
{
|
||||
@ -1678,60 +1360,9 @@ static int tcp_prepare_flags(struct ctx *c, struct tcp_tap_conn *conn,
|
||||
*
|
||||
* Return: negative error code on connection reset, 0 otherwise
|
||||
*/
|
||||
static int tcp_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags)
|
||||
int tcp_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags)
|
||||
{
|
||||
struct tcp_flags_t *payload;
|
||||
struct iovec *iov;
|
||||
size_t optlen;
|
||||
size_t l4len;
|
||||
uint32_t seq;
|
||||
int ret;
|
||||
|
||||
if (CONN_V4(conn))
|
||||
iov = tcp4_l2_flags_iov[tcp4_flags_used++];
|
||||
else
|
||||
iov = tcp6_l2_flags_iov[tcp6_flags_used++];
|
||||
|
||||
payload = iov[TCP_IOV_PAYLOAD].iov_base;
|
||||
|
||||
seq = conn->seq_to_tap;
|
||||
ret = tcp_prepare_flags(c, conn, flags, &payload->th,
|
||||
payload->opts, &optlen);
|
||||
if (ret <= 0) {
|
||||
if (CONN_V4(conn))
|
||||
tcp4_flags_used--;
|
||||
else
|
||||
tcp6_flags_used--;
|
||||
return ret;
|
||||
}
|
||||
|
||||
l4len = tcp_l2_buf_fill_headers(c, conn, iov, optlen, NULL, seq);
|
||||
iov[TCP_IOV_PAYLOAD].iov_len = l4len;
|
||||
|
||||
if (flags & DUP_ACK) {
|
||||
struct iovec *dup_iov;
|
||||
int i;
|
||||
|
||||
if (CONN_V4(conn))
|
||||
dup_iov = tcp4_l2_flags_iov[tcp4_flags_used++];
|
||||
else
|
||||
dup_iov = tcp6_l2_flags_iov[tcp6_flags_used++];
|
||||
|
||||
for (i = 0; i < TCP_NUM_IOVS; i++)
|
||||
memcpy(dup_iov[i].iov_base, iov[i].iov_base,
|
||||
iov[i].iov_len);
|
||||
dup_iov[TCP_IOV_PAYLOAD].iov_len = iov[TCP_IOV_PAYLOAD].iov_len;
|
||||
}
|
||||
|
||||
if (CONN_V4(conn)) {
|
||||
if (tcp4_flags_used > TCP_FRAMES_MEM - 2)
|
||||
tcp_flags_flush(c);
|
||||
} else {
|
||||
if (tcp6_flags_used > TCP_FRAMES_MEM - 2)
|
||||
tcp_flags_flush(c);
|
||||
}
|
||||
|
||||
return 0;
|
||||
return tcp_buf_send_flag(c, conn, flags);
|
||||
}
|
||||
|
||||
/**
|
||||
@ -1739,7 +1370,7 @@ static int tcp_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags)
|
||||
* @c: Execution context
|
||||
* @conn: Connection pointer
|
||||
*/
|
||||
static void tcp_rst_do(struct ctx *c, struct tcp_tap_conn *conn)
|
||||
void tcp_rst_do(struct ctx *c, struct tcp_tap_conn *conn)
|
||||
{
|
||||
if (conn->events == CLOSED)
|
||||
return;
|
||||
@ -2166,49 +1797,6 @@ static int tcp_sock_consume(const struct tcp_tap_conn *conn, uint32_t ack_seq)
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* tcp_data_to_tap() - Finalise (queue) highest-numbered scatter-gather buffer
|
||||
* @c: Execution context
|
||||
* @conn: Connection pointer
|
||||
* @dlen: TCP payload length
|
||||
* @no_csum: Don't compute IPv4 checksum, use the one from previous buffer
|
||||
* @seq: Sequence number to be sent
|
||||
*/
|
||||
static void tcp_data_to_tap(const struct ctx *c, struct tcp_tap_conn *conn,
|
||||
ssize_t dlen, int no_csum, uint32_t seq)
|
||||
{
|
||||
struct iovec *iov;
|
||||
size_t l4len;
|
||||
|
||||
conn->seq_to_tap = seq + dlen;
|
||||
|
||||
if (CONN_V4(conn)) {
|
||||
struct iovec *iov_prev = tcp4_l2_iov[tcp4_payload_used - 1];
|
||||
const uint16_t *check = NULL;
|
||||
|
||||
if (no_csum) {
|
||||
struct iphdr *iph = iov_prev[TCP_IOV_IP].iov_base;
|
||||
check = &iph->check;
|
||||
}
|
||||
|
||||
tcp4_frame_conns[tcp4_payload_used] = conn;
|
||||
|
||||
iov = tcp4_l2_iov[tcp4_payload_used++];
|
||||
l4len = tcp_l2_buf_fill_headers(c, conn, iov, dlen, check, seq);
|
||||
iov[TCP_IOV_PAYLOAD].iov_len = l4len;
|
||||
if (tcp4_payload_used > TCP_FRAMES_MEM - 1)
|
||||
tcp_payload_flush(c);
|
||||
} else if (CONN_V6(conn)) {
|
||||
tcp6_frame_conns[tcp6_payload_used] = conn;
|
||||
|
||||
iov = tcp6_l2_iov[tcp6_payload_used++];
|
||||
l4len = tcp_l2_buf_fill_headers(c, conn, iov, dlen, NULL, seq);
|
||||
iov[TCP_IOV_PAYLOAD].iov_len = l4len;
|
||||
if (tcp6_payload_used > TCP_FRAMES_MEM - 1)
|
||||
tcp_payload_flush(c);
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* tcp_data_from_sock() - Handle new data from socket, queue to tap, in window
|
||||
* @c: Execution context
|
||||
@ -2220,123 +1808,7 @@ static void tcp_data_to_tap(const struct ctx *c, struct tcp_tap_conn *conn,
|
||||
*/
|
||||
static int tcp_data_from_sock(struct ctx *c, struct tcp_tap_conn *conn)
|
||||
{
|
||||
uint32_t wnd_scaled = conn->wnd_from_tap << conn->ws_from_tap;
|
||||
int fill_bufs, send_bufs = 0, last_len, iov_rem = 0;
|
||||
int sendlen, len, dlen, v4 = CONN_V4(conn);
|
||||
int s = conn->sock, i, ret = 0;
|
||||
struct msghdr mh_sock = { 0 };
|
||||
uint16_t mss = MSS_GET(conn);
|
||||
uint32_t already_sent, seq;
|
||||
struct iovec *iov;
|
||||
|
||||
already_sent = conn->seq_to_tap - conn->seq_ack_from_tap;
|
||||
|
||||
if (SEQ_LT(already_sent, 0)) {
|
||||
/* RFC 761, section 2.1. */
|
||||
flow_trace(conn, "ACK sequence gap: ACK for %u, sent: %u",
|
||||
conn->seq_ack_from_tap, conn->seq_to_tap);
|
||||
conn->seq_to_tap = conn->seq_ack_from_tap;
|
||||
already_sent = 0;
|
||||
}
|
||||
|
||||
if (!wnd_scaled || already_sent >= wnd_scaled) {
|
||||
conn_flag(c, conn, STALLED);
|
||||
conn_flag(c, conn, ACK_FROM_TAP_DUE);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* Set up buffer descriptors we'll fill completely and partially. */
|
||||
fill_bufs = DIV_ROUND_UP(wnd_scaled - already_sent, mss);
|
||||
if (fill_bufs > TCP_FRAMES) {
|
||||
fill_bufs = TCP_FRAMES;
|
||||
iov_rem = 0;
|
||||
} else {
|
||||
iov_rem = (wnd_scaled - already_sent) % mss;
|
||||
}
|
||||
|
||||
mh_sock.msg_iov = iov_sock;
|
||||
mh_sock.msg_iovlen = fill_bufs + 1;
|
||||
|
||||
iov_sock[0].iov_base = tcp_buf_discard;
|
||||
iov_sock[0].iov_len = already_sent;
|
||||
|
||||
if (( v4 && tcp4_payload_used + fill_bufs > TCP_FRAMES_MEM) ||
|
||||
(!v4 && tcp6_payload_used + fill_bufs > TCP_FRAMES_MEM)) {
|
||||
tcp_payload_flush(c);
|
||||
|
||||
/* Silence Coverity CWE-125 false positive */
|
||||
tcp4_payload_used = tcp6_payload_used = 0;
|
||||
}
|
||||
|
||||
for (i = 0, iov = iov_sock + 1; i < fill_bufs; i++, iov++) {
|
||||
if (v4)
|
||||
iov->iov_base = &tcp4_payload[tcp4_payload_used + i].data;
|
||||
else
|
||||
iov->iov_base = &tcp6_payload[tcp6_payload_used + i].data;
|
||||
iov->iov_len = mss;
|
||||
}
|
||||
if (iov_rem)
|
||||
iov_sock[fill_bufs].iov_len = iov_rem;
|
||||
|
||||
/* Receive into buffers, don't dequeue until acknowledged by guest. */
|
||||
do
|
||||
len = recvmsg(s, &mh_sock, MSG_PEEK);
|
||||
while (len < 0 && errno == EINTR);
|
||||
|
||||
if (len < 0)
|
||||
goto err;
|
||||
|
||||
if (!len) {
|
||||
if ((conn->events & (SOCK_FIN_RCVD | TAP_FIN_SENT)) == SOCK_FIN_RCVD) {
|
||||
if ((ret = tcp_send_flag(c, conn, FIN | ACK))) {
|
||||
tcp_rst(c, conn);
|
||||
return ret;
|
||||
}
|
||||
|
||||
conn_event(c, conn, TAP_FIN_SENT);
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
sendlen = len - already_sent;
|
||||
if (sendlen <= 0) {
|
||||
conn_flag(c, conn, STALLED);
|
||||
return 0;
|
||||
}
|
||||
|
||||
conn_flag(c, conn, ~STALLED);
|
||||
|
||||
send_bufs = DIV_ROUND_UP(sendlen, mss);
|
||||
last_len = sendlen - (send_bufs - 1) * mss;
|
||||
|
||||
/* Likely, some new data was acked too. */
|
||||
tcp_update_seqack_wnd(c, conn, 0, NULL);
|
||||
|
||||
/* Finally, queue to tap */
|
||||
dlen = mss;
|
||||
seq = conn->seq_to_tap;
|
||||
for (i = 0; i < send_bufs; i++) {
|
||||
int no_csum = i && i != send_bufs - 1 && tcp4_payload_used;
|
||||
|
||||
if (i == send_bufs - 1)
|
||||
dlen = last_len;
|
||||
|
||||
tcp_data_to_tap(c, conn, dlen, no_csum, seq);
|
||||
seq += dlen;
|
||||
}
|
||||
|
||||
conn_flag(c, conn, ACK_FROM_TAP_DUE);
|
||||
|
||||
return 0;
|
||||
|
||||
err:
|
||||
if (errno != EAGAIN && errno != EWOULDBLOCK) {
|
||||
ret = -errno;
|
||||
tcp_rst(c, conn);
|
||||
}
|
||||
|
||||
return ret;
|
||||
return tcp_buf_data_from_sock(c, conn);
|
||||
}
|
||||
|
||||
/**
|
||||
|
||||
519
tcp_buf.c
Normal file
519
tcp_buf.c
Normal file
@ -0,0 +1,519 @@
|
||||
// SPDX-License-Identifier: GPL-2.0-or-later
|
||||
|
||||
/* PASST - Plug A Simple Socket Transport
|
||||
* for qemu/UNIX domain socket mode
|
||||
*
|
||||
* PASTA - Pack A Subtle Tap Abstraction
|
||||
* for network namespace/tap device mode
|
||||
*
|
||||
* tcp_buf.c - TCP L2 buffer management functions
|
||||
*
|
||||
* Copyright Red Hat
|
||||
* Author: Stefano Brivio <sbrivio@redhat.com>
|
||||
*/
|
||||
|
||||
#include <stddef.h>
|
||||
#include <stdint.h>
|
||||
#include <limits.h>
|
||||
#include <string.h>
|
||||
#include <errno.h>
|
||||
|
||||
#include <netinet/ip.h>
|
||||
|
||||
#include <linux/tcp.h>
|
||||
|
||||
#include "util.h"
|
||||
#include "ip.h"
|
||||
#include "iov.h"
|
||||
#include "passt.h"
|
||||
#include "tap.h"
|
||||
#include "siphash.h"
|
||||
#include "inany.h"
|
||||
#include "tcp_conn.h"
|
||||
#include "tcp_internal.h"
|
||||
#include "tcp_buf.h"
|
||||
|
||||
#define TCP_FRAMES_MEM 128
|
||||
#define TCP_FRAMES \
|
||||
(c->mode == MODE_PASST ? TCP_FRAMES_MEM : 1)
|
||||
|
||||
/* Static buffers */
|
||||
/**
|
||||
* struct tcp_payload_t - TCP header and data to send segments with payload
|
||||
* @th: TCP header
|
||||
* @data: TCP data
|
||||
*/
|
||||
struct tcp_payload_t {
|
||||
struct tcphdr th;
|
||||
uint8_t data[IP_MAX_MTU - sizeof(struct tcphdr)];
|
||||
#ifdef __AVX2__
|
||||
} __attribute__ ((packed, aligned(32))); /* For AVX2 checksum routines */
|
||||
#else
|
||||
} __attribute__ ((packed, aligned(__alignof__(unsigned int))));
|
||||
#endif
|
||||
|
||||
/**
|
||||
* struct tcp_flags_t - TCP header and data to send zero-length
|
||||
* segments (flags)
|
||||
* @th: TCP header
|
||||
* @opts TCP options
|
||||
*/
|
||||
struct tcp_flags_t {
|
||||
struct tcphdr th;
|
||||
char opts[OPT_MSS_LEN + OPT_WS_LEN + 1];
|
||||
#ifdef __AVX2__
|
||||
} __attribute__ ((packed, aligned(32)));
|
||||
#else
|
||||
} __attribute__ ((packed, aligned(__alignof__(unsigned int))));
|
||||
#endif
|
||||
|
||||
/* Ethernet header for IPv4 frames */
|
||||
static struct ethhdr tcp4_eth_src;
|
||||
|
||||
static struct tap_hdr tcp4_payload_tap_hdr[TCP_FRAMES_MEM];
|
||||
/* IPv4 headers */
|
||||
static struct iphdr tcp4_payload_ip[TCP_FRAMES_MEM];
|
||||
/* TCP segments with payload for IPv4 frames */
|
||||
static struct tcp_payload_t tcp4_payload[TCP_FRAMES_MEM];
|
||||
|
||||
static_assert(MSS4 <= sizeof(tcp4_payload[0].data), "MSS4 is greater than 65516");
|
||||
|
||||
/* References tracking the owner connection of frames in the tap outqueue */
|
||||
static struct tcp_tap_conn *tcp4_frame_conns[TCP_FRAMES_MEM];
|
||||
static unsigned int tcp4_payload_used;
|
||||
|
||||
static struct tap_hdr tcp4_flags_tap_hdr[TCP_FRAMES_MEM];
|
||||
/* IPv4 headers for TCP segment without payload */
|
||||
static struct iphdr tcp4_flags_ip[TCP_FRAMES_MEM];
|
||||
/* TCP segments without payload for IPv4 frames */
|
||||
static struct tcp_flags_t tcp4_flags[TCP_FRAMES_MEM];
|
||||
|
||||
static unsigned int tcp4_flags_used;
|
||||
|
||||
/* Ethernet header for IPv6 frames */
|
||||
static struct ethhdr tcp6_eth_src;
|
||||
|
||||
static struct tap_hdr tcp6_payload_tap_hdr[TCP_FRAMES_MEM];
|
||||
/* IPv6 headers */
|
||||
static struct ipv6hdr tcp6_payload_ip[TCP_FRAMES_MEM];
|
||||
/* TCP headers and data for IPv6 frames */
|
||||
static struct tcp_payload_t tcp6_payload[TCP_FRAMES_MEM];
|
||||
|
||||
static_assert(MSS6 <= sizeof(tcp6_payload[0].data), "MSS6 is greater than 65516");
|
||||
|
||||
/* References tracking the owner connection of frames in the tap outqueue */
|
||||
static struct tcp_tap_conn *tcp6_frame_conns[TCP_FRAMES_MEM];
|
||||
static unsigned int tcp6_payload_used;
|
||||
|
||||
static struct tap_hdr tcp6_flags_tap_hdr[TCP_FRAMES_MEM];
|
||||
/* IPv6 headers for TCP segment without payload */
|
||||
static struct ipv6hdr tcp6_flags_ip[TCP_FRAMES_MEM];
|
||||
/* TCP segment without payload for IPv6 frames */
|
||||
static struct tcp_flags_t tcp6_flags[TCP_FRAMES_MEM];
|
||||
|
||||
static unsigned int tcp6_flags_used;
|
||||
|
||||
/* recvmsg()/sendmsg() data for tap */
|
||||
static struct iovec iov_sock [TCP_FRAMES_MEM + 1];
|
||||
|
||||
static struct iovec tcp4_l2_iov [TCP_FRAMES_MEM][TCP_NUM_IOVS];
|
||||
static struct iovec tcp6_l2_iov [TCP_FRAMES_MEM][TCP_NUM_IOVS];
|
||||
static struct iovec tcp4_l2_flags_iov [TCP_FRAMES_MEM][TCP_NUM_IOVS];
|
||||
static struct iovec tcp6_l2_flags_iov [TCP_FRAMES_MEM][TCP_NUM_IOVS];
|
||||
/**
|
||||
* tcp_update_l2_buf() - Update Ethernet header buffers with addresses
|
||||
* @eth_d: Ethernet destination address, NULL if unchanged
|
||||
* @eth_s: Ethernet source address, NULL if unchanged
|
||||
*/
|
||||
void tcp_update_l2_buf(const unsigned char *eth_d, const unsigned char *eth_s)
|
||||
{
|
||||
eth_update_mac(&tcp4_eth_src, eth_d, eth_s);
|
||||
eth_update_mac(&tcp6_eth_src, eth_d, eth_s);
|
||||
}
|
||||
|
||||
/**
|
||||
* tcp_sock4_iov_init() - Initialise scatter-gather L2 buffers for IPv4 sockets
|
||||
* @c: Execution context
|
||||
*/
|
||||
void tcp_sock4_iov_init(const struct ctx *c)
|
||||
{
|
||||
struct iphdr iph = L2_BUF_IP4_INIT(IPPROTO_TCP);
|
||||
struct iovec *iov;
|
||||
int i;
|
||||
|
||||
tcp4_eth_src.h_proto = htons_constant(ETH_P_IP);
|
||||
|
||||
for (i = 0; i < ARRAY_SIZE(tcp4_payload); i++) {
|
||||
tcp4_payload_ip[i] = iph;
|
||||
tcp4_payload[i].th.doff = sizeof(struct tcphdr) / 4;
|
||||
tcp4_payload[i].th.ack = 1;
|
||||
}
|
||||
|
||||
for (i = 0; i < ARRAY_SIZE(tcp4_flags); i++) {
|
||||
tcp4_flags_ip[i] = iph;
|
||||
tcp4_flags[i].th.doff = sizeof(struct tcphdr) / 4;
|
||||
tcp4_flags[i].th.ack = 1;
|
||||
}
|
||||
|
||||
for (i = 0; i < TCP_FRAMES_MEM; i++) {
|
||||
iov = tcp4_l2_iov[i];
|
||||
|
||||
iov[TCP_IOV_TAP] = tap_hdr_iov(c, &tcp4_payload_tap_hdr[i]);
|
||||
iov[TCP_IOV_ETH] = IOV_OF_LVALUE(tcp4_eth_src);
|
||||
iov[TCP_IOV_IP] = IOV_OF_LVALUE(tcp4_payload_ip[i]);
|
||||
iov[TCP_IOV_PAYLOAD].iov_base = &tcp4_payload[i];
|
||||
}
|
||||
|
||||
for (i = 0; i < TCP_FRAMES_MEM; i++) {
|
||||
iov = tcp4_l2_flags_iov[i];
|
||||
|
||||
iov[TCP_IOV_TAP] = tap_hdr_iov(c, &tcp4_flags_tap_hdr[i]);
|
||||
iov[TCP_IOV_ETH].iov_base = &tcp4_eth_src;
|
||||
iov[TCP_IOV_ETH] = IOV_OF_LVALUE(tcp4_eth_src);
|
||||
iov[TCP_IOV_IP] = IOV_OF_LVALUE(tcp4_flags_ip[i]);
|
||||
iov[TCP_IOV_PAYLOAD].iov_base = &tcp4_flags[i];
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* tcp_sock6_iov_init() - Initialise scatter-gather L2 buffers for IPv6 sockets
|
||||
* @c: Execution context
|
||||
*/
|
||||
void tcp_sock6_iov_init(const struct ctx *c)
|
||||
{
|
||||
struct ipv6hdr ip6 = L2_BUF_IP6_INIT(IPPROTO_TCP);
|
||||
struct iovec *iov;
|
||||
int i;
|
||||
|
||||
tcp6_eth_src.h_proto = htons_constant(ETH_P_IPV6);
|
||||
|
||||
for (i = 0; i < ARRAY_SIZE(tcp6_payload); i++) {
|
||||
tcp6_payload_ip[i] = ip6;
|
||||
tcp6_payload[i].th.doff = sizeof(struct tcphdr) / 4;
|
||||
tcp6_payload[i].th.ack = 1;
|
||||
}
|
||||
|
||||
for (i = 0; i < ARRAY_SIZE(tcp6_flags); i++) {
|
||||
tcp6_flags_ip[i] = ip6;
|
||||
tcp6_flags[i].th.doff = sizeof(struct tcphdr) / 4;
|
||||
tcp6_flags[i].th .ack = 1;
|
||||
}
|
||||
|
||||
for (i = 0; i < TCP_FRAMES_MEM; i++) {
|
||||
iov = tcp6_l2_iov[i];
|
||||
|
||||
iov[TCP_IOV_TAP] = tap_hdr_iov(c, &tcp6_payload_tap_hdr[i]);
|
||||
iov[TCP_IOV_ETH] = IOV_OF_LVALUE(tcp6_eth_src);
|
||||
iov[TCP_IOV_IP] = IOV_OF_LVALUE(tcp6_payload_ip[i]);
|
||||
iov[TCP_IOV_PAYLOAD].iov_base = &tcp6_payload[i];
|
||||
}
|
||||
|
||||
for (i = 0; i < TCP_FRAMES_MEM; i++) {
|
||||
iov = tcp6_l2_flags_iov[i];
|
||||
|
||||
iov[TCP_IOV_TAP] = tap_hdr_iov(c, &tcp6_flags_tap_hdr[i]);
|
||||
iov[TCP_IOV_ETH] = IOV_OF_LVALUE(tcp6_eth_src);
|
||||
iov[TCP_IOV_IP] = IOV_OF_LVALUE(tcp6_flags_ip[i]);
|
||||
iov[TCP_IOV_PAYLOAD].iov_base = &tcp6_flags[i];
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* tcp_flags_flush() - Send out buffers for segments with no data (flags)
|
||||
* @c: Execution context
|
||||
*/
|
||||
void tcp_flags_flush(const struct ctx *c)
|
||||
{
|
||||
tap_send_frames(c, &tcp6_l2_flags_iov[0][0], TCP_NUM_IOVS,
|
||||
tcp6_flags_used);
|
||||
tcp6_flags_used = 0;
|
||||
|
||||
tap_send_frames(c, &tcp4_l2_flags_iov[0][0], TCP_NUM_IOVS,
|
||||
tcp4_flags_used);
|
||||
tcp4_flags_used = 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* tcp_revert_seq() - Revert affected conn->seq_to_tap after failed transmission
|
||||
* @conns: Array of connection pointers corresponding to queued frames
|
||||
* @frames: Two-dimensional array containing queued frames with sub-iovs
|
||||
* @num_frames: Number of entries in the two arrays to be compared
|
||||
*/
|
||||
static void tcp_revert_seq(struct tcp_tap_conn **conns, struct iovec (*frames)[TCP_NUM_IOVS],
|
||||
int num_frames)
|
||||
{
|
||||
int i;
|
||||
|
||||
for (i = 0; i < num_frames; i++) {
|
||||
const struct tcphdr *th = frames[i][TCP_IOV_PAYLOAD].iov_base;
|
||||
struct tcp_tap_conn *conn = conns[i];
|
||||
uint32_t seq = ntohl(th->seq);
|
||||
|
||||
if (SEQ_LE(conn->seq_to_tap, seq))
|
||||
continue;
|
||||
|
||||
conn->seq_to_tap = seq;
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* tcp_payload_flush() - Send out buffers for segments with data
|
||||
* @c: Execution context
|
||||
*/
|
||||
void tcp_payload_flush(const struct ctx *c)
|
||||
{
|
||||
size_t m;
|
||||
|
||||
m = tap_send_frames(c, &tcp6_l2_iov[0][0], TCP_NUM_IOVS,
|
||||
tcp6_payload_used);
|
||||
if (m != tcp6_payload_used) {
|
||||
tcp_revert_seq(&tcp6_frame_conns[m], &tcp6_l2_iov[m],
|
||||
tcp6_payload_used - m);
|
||||
}
|
||||
tcp6_payload_used = 0;
|
||||
|
||||
m = tap_send_frames(c, &tcp4_l2_iov[0][0], TCP_NUM_IOVS,
|
||||
tcp4_payload_used);
|
||||
if (m != tcp4_payload_used) {
|
||||
tcp_revert_seq(&tcp4_frame_conns[m], &tcp4_l2_iov[m],
|
||||
tcp4_payload_used - m);
|
||||
}
|
||||
tcp4_payload_used = 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* tcp_buf_send_flag() - Send segment with flags to tap (no payload)
|
||||
* @c: Execution context
|
||||
* @conn: Connection pointer
|
||||
* @flags: TCP flags: if not set, send segment only if ACK is due
|
||||
*
|
||||
* Return: negative error code on connection reset, 0 otherwise
|
||||
*/
|
||||
int tcp_buf_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags)
|
||||
{
|
||||
struct tcp_flags_t *payload;
|
||||
struct iovec *iov;
|
||||
size_t optlen;
|
||||
size_t l4len;
|
||||
uint32_t seq;
|
||||
int ret;
|
||||
|
||||
if (CONN_V4(conn))
|
||||
iov = tcp4_l2_flags_iov[tcp4_flags_used++];
|
||||
else
|
||||
iov = tcp6_l2_flags_iov[tcp6_flags_used++];
|
||||
|
||||
payload = iov[TCP_IOV_PAYLOAD].iov_base;
|
||||
|
||||
seq = conn->seq_to_tap;
|
||||
ret = tcp_prepare_flags(c, conn, flags, &payload->th,
|
||||
payload->opts, &optlen);
|
||||
if (ret <= 0) {
|
||||
if (CONN_V4(conn))
|
||||
tcp4_flags_used--;
|
||||
else
|
||||
tcp6_flags_used--;
|
||||
return ret;
|
||||
}
|
||||
|
||||
l4len = tcp_l2_buf_fill_headers(c, conn, iov, optlen, NULL, seq);
|
||||
iov[TCP_IOV_PAYLOAD].iov_len = l4len;
|
||||
|
||||
if (flags & DUP_ACK) {
|
||||
struct iovec *dup_iov;
|
||||
int i;
|
||||
|
||||
if (CONN_V4(conn))
|
||||
dup_iov = tcp4_l2_flags_iov[tcp4_flags_used++];
|
||||
else
|
||||
dup_iov = tcp6_l2_flags_iov[tcp6_flags_used++];
|
||||
|
||||
for (i = 0; i < TCP_NUM_IOVS; i++)
|
||||
memcpy(dup_iov[i].iov_base, iov[i].iov_base,
|
||||
iov[i].iov_len);
|
||||
dup_iov[TCP_IOV_PAYLOAD].iov_len = iov[TCP_IOV_PAYLOAD].iov_len;
|
||||
}
|
||||
|
||||
if (CONN_V4(conn)) {
|
||||
if (tcp4_flags_used > TCP_FRAMES_MEM - 2)
|
||||
tcp_flags_flush(c);
|
||||
} else {
|
||||
if (tcp6_flags_used > TCP_FRAMES_MEM - 2)
|
||||
tcp_flags_flush(c);
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* tcp_data_to_tap() - Finalise (queue) highest-numbered scatter-gather buffer
|
||||
* @c: Execution context
|
||||
* @conn: Connection pointer
|
||||
* @dlen: TCP payload length
|
||||
* @no_csum: Don't compute IPv4 checksum, use the one from previous buffer
|
||||
* @seq: Sequence number to be sent
|
||||
*/
|
||||
static void tcp_data_to_tap(const struct ctx *c, struct tcp_tap_conn *conn,
|
||||
ssize_t dlen, int no_csum, uint32_t seq)
|
||||
{
|
||||
struct iovec *iov;
|
||||
size_t l4len;
|
||||
|
||||
conn->seq_to_tap = seq + dlen;
|
||||
|
||||
if (CONN_V4(conn)) {
|
||||
struct iovec *iov_prev = tcp4_l2_iov[tcp4_payload_used - 1];
|
||||
const uint16_t *check = NULL;
|
||||
|
||||
if (no_csum) {
|
||||
struct iphdr *iph = iov_prev[TCP_IOV_IP].iov_base;
|
||||
check = &iph->check;
|
||||
}
|
||||
|
||||
tcp4_frame_conns[tcp4_payload_used] = conn;
|
||||
|
||||
iov = tcp4_l2_iov[tcp4_payload_used++];
|
||||
l4len = tcp_l2_buf_fill_headers(c, conn, iov, dlen, check, seq);
|
||||
iov[TCP_IOV_PAYLOAD].iov_len = l4len;
|
||||
if (tcp4_payload_used > TCP_FRAMES_MEM - 1)
|
||||
tcp_payload_flush(c);
|
||||
} else if (CONN_V6(conn)) {
|
||||
tcp6_frame_conns[tcp6_payload_used] = conn;
|
||||
|
||||
iov = tcp6_l2_iov[tcp6_payload_used++];
|
||||
l4len = tcp_l2_buf_fill_headers(c, conn, iov, dlen, NULL, seq);
|
||||
iov[TCP_IOV_PAYLOAD].iov_len = l4len;
|
||||
if (tcp6_payload_used > TCP_FRAMES_MEM - 1)
|
||||
tcp_payload_flush(c);
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* tcp_buf_data_from_sock() - Handle new data from socket, queue to tap, in window
|
||||
* @c: Execution context
|
||||
* @conn: Connection pointer
|
||||
*
|
||||
* Return: negative on connection reset, 0 otherwise
|
||||
*
|
||||
* #syscalls recvmsg
|
||||
*/
|
||||
int tcp_buf_data_from_sock(struct ctx *c, struct tcp_tap_conn *conn)
|
||||
{
|
||||
uint32_t wnd_scaled = conn->wnd_from_tap << conn->ws_from_tap;
|
||||
int fill_bufs, send_bufs = 0, last_len, iov_rem = 0;
|
||||
int sendlen, len, dlen, v4 = CONN_V4(conn);
|
||||
int s = conn->sock, i, ret = 0;
|
||||
struct msghdr mh_sock = { 0 };
|
||||
uint16_t mss = MSS_GET(conn);
|
||||
uint32_t already_sent, seq;
|
||||
struct iovec *iov;
|
||||
|
||||
already_sent = conn->seq_to_tap - conn->seq_ack_from_tap;
|
||||
|
||||
if (SEQ_LT(already_sent, 0)) {
|
||||
/* RFC 761, section 2.1. */
|
||||
flow_trace(conn, "ACK sequence gap: ACK for %u, sent: %u",
|
||||
conn->seq_ack_from_tap, conn->seq_to_tap);
|
||||
conn->seq_to_tap = conn->seq_ack_from_tap;
|
||||
already_sent = 0;
|
||||
}
|
||||
|
||||
if (!wnd_scaled || already_sent >= wnd_scaled) {
|
||||
conn_flag(c, conn, STALLED);
|
||||
conn_flag(c, conn, ACK_FROM_TAP_DUE);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* Set up buffer descriptors we'll fill completely and partially. */
|
||||
fill_bufs = DIV_ROUND_UP(wnd_scaled - already_sent, mss);
|
||||
if (fill_bufs > TCP_FRAMES) {
|
||||
fill_bufs = TCP_FRAMES;
|
||||
iov_rem = 0;
|
||||
} else {
|
||||
iov_rem = (wnd_scaled - already_sent) % mss;
|
||||
}
|
||||
|
||||
mh_sock.msg_iov = iov_sock;
|
||||
mh_sock.msg_iovlen = fill_bufs + 1;
|
||||
|
||||
iov_sock[0].iov_base = tcp_buf_discard;
|
||||
iov_sock[0].iov_len = already_sent;
|
||||
|
||||
if (( v4 && tcp4_payload_used + fill_bufs > TCP_FRAMES_MEM) ||
|
||||
(!v4 && tcp6_payload_used + fill_bufs > TCP_FRAMES_MEM)) {
|
||||
tcp_payload_flush(c);
|
||||
|
||||
/* Silence Coverity CWE-125 false positive */
|
||||
tcp4_payload_used = tcp6_payload_used = 0;
|
||||
}
|
||||
|
||||
for (i = 0, iov = iov_sock + 1; i < fill_bufs; i++, iov++) {
|
||||
if (v4)
|
||||
iov->iov_base = &tcp4_payload[tcp4_payload_used + i].data;
|
||||
else
|
||||
iov->iov_base = &tcp6_payload[tcp6_payload_used + i].data;
|
||||
iov->iov_len = mss;
|
||||
}
|
||||
if (iov_rem)
|
||||
iov_sock[fill_bufs].iov_len = iov_rem;
|
||||
|
||||
/* Receive into buffers, don't dequeue until acknowledged by guest. */
|
||||
do
|
||||
len = recvmsg(s, &mh_sock, MSG_PEEK);
|
||||
while (len < 0 && errno == EINTR);
|
||||
|
||||
if (len < 0)
|
||||
goto err;
|
||||
|
||||
if (!len) {
|
||||
if ((conn->events & (SOCK_FIN_RCVD | TAP_FIN_SENT)) == SOCK_FIN_RCVD) {
|
||||
if ((ret = tcp_buf_send_flag(c, conn, FIN | ACK))) {
|
||||
tcp_rst(c, conn);
|
||||
return ret;
|
||||
}
|
||||
|
||||
conn_event(c, conn, TAP_FIN_SENT);
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
sendlen = len - already_sent;
|
||||
if (sendlen <= 0) {
|
||||
conn_flag(c, conn, STALLED);
|
||||
return 0;
|
||||
}
|
||||
|
||||
conn_flag(c, conn, ~STALLED);
|
||||
|
||||
send_bufs = DIV_ROUND_UP(sendlen, mss);
|
||||
last_len = sendlen - (send_bufs - 1) * mss;
|
||||
|
||||
/* Likely, some new data was acked too. */
|
||||
tcp_update_seqack_wnd(c, conn, 0, NULL);
|
||||
|
||||
/* Finally, queue to tap */
|
||||
dlen = mss;
|
||||
seq = conn->seq_to_tap;
|
||||
for (i = 0; i < send_bufs; i++) {
|
||||
int no_csum = i && i != send_bufs - 1 && tcp4_payload_used;
|
||||
|
||||
if (i == send_bufs - 1)
|
||||
dlen = last_len;
|
||||
|
||||
tcp_data_to_tap(c, conn, dlen, no_csum, seq);
|
||||
seq += dlen;
|
||||
}
|
||||
|
||||
conn_flag(c, conn, ACK_FROM_TAP_DUE);
|
||||
|
||||
return 0;
|
||||
|
||||
err:
|
||||
if (errno != EAGAIN && errno != EWOULDBLOCK) {
|
||||
ret = -errno;
|
||||
tcp_rst(c, conn);
|
||||
}
|
||||
|
||||
return ret;
|
||||
}
|
||||
16
tcp_buf.h
Normal file
16
tcp_buf.h
Normal file
@ -0,0 +1,16 @@
|
||||
/* SPDX-License-Identifier: GPL-2.0-or-later
|
||||
* Copyright (c) 2021 Red Hat GmbH
|
||||
* Author: Stefano Brivio <sbrivio@redhat.com>
|
||||
*/
|
||||
|
||||
#ifndef TCP_BUF_H
|
||||
#define TCP_BUF_H
|
||||
|
||||
void tcp_sock4_iov_init(const struct ctx *c);
|
||||
void tcp_sock6_iov_init(const struct ctx *c);
|
||||
void tcp_flags_flush(const struct ctx *c);
|
||||
void tcp_payload_flush(const struct ctx *c);
|
||||
int tcp_buf_data_from_sock(struct ctx *c, struct tcp_tap_conn *conn);
|
||||
int tcp_buf_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags);
|
||||
|
||||
#endif /*TCP_BUF_H */
|
||||
96
tcp_internal.h
Normal file
96
tcp_internal.h
Normal file
@ -0,0 +1,96 @@
|
||||
/* SPDX-License-Identifier: GPL-2.0-or-later
|
||||
* Copyright (c) 2021 Red Hat GmbH
|
||||
* Author: Stefano Brivio <sbrivio@redhat.com>
|
||||
*/
|
||||
|
||||
#ifndef TCP_INTERNAL_H
|
||||
#define TCP_INTERNAL_H
|
||||
|
||||
#define MAX_WS 8
|
||||
#define MAX_WINDOW (1 << (16 + (MAX_WS)))
|
||||
|
||||
#define MSS4 ROUND_DOWN(IP_MAX_MTU - \
|
||||
sizeof(struct tcphdr) - \
|
||||
sizeof(struct iphdr), \
|
||||
sizeof(uint32_t))
|
||||
#define MSS6 ROUND_DOWN(IP_MAX_MTU - \
|
||||
sizeof(struct tcphdr) - \
|
||||
sizeof(struct ipv6hdr), \
|
||||
sizeof(uint32_t))
|
||||
|
||||
#define SEQ_LE(a, b) ((b) - (a) < MAX_WINDOW)
|
||||
#define SEQ_LT(a, b) ((b) - (a) - 1 < MAX_WINDOW)
|
||||
#define SEQ_GE(a, b) ((a) - (b) < MAX_WINDOW)
|
||||
#define SEQ_GT(a, b) ((a) - (b) - 1 < MAX_WINDOW)
|
||||
|
||||
#define FIN (1 << 0)
|
||||
#define SYN (1 << 1)
|
||||
#define RST (1 << 2)
|
||||
#define ACK (1 << 4)
|
||||
|
||||
/* Flags for internal usage */
|
||||
#define DUP_ACK (1 << 5)
|
||||
#define OPT_EOL 0
|
||||
#define OPT_NOP 1
|
||||
#define OPT_MSS 2
|
||||
#define OPT_MSS_LEN 4
|
||||
#define OPT_WS 3
|
||||
#define OPT_WS_LEN 3
|
||||
#define OPT_SACKP 4
|
||||
#define OPT_SACK 5
|
||||
#define OPT_TS 8
|
||||
#define CONN_V4(conn) (!!inany_v4(&(conn)->faddr))
|
||||
#define CONN_V6(conn) (!CONN_V4(conn))
|
||||
|
||||
/*
|
||||
* enum tcp_iov_parts - I/O vector parts for one TCP frame
|
||||
* @TCP_IOV_TAP tap backend specific header
|
||||
* @TCP_IOV_ETH Ethernet header
|
||||
* @TCP_IOV_IP IP (v4/v6) header
|
||||
* @TCP_IOV_PAYLOAD IP payload (TCP header + data)
|
||||
* @TCP_NUM_IOVS the number of entries in the iovec array
|
||||
*/
|
||||
enum tcp_iov_parts {
|
||||
TCP_IOV_TAP = 0,
|
||||
TCP_IOV_ETH = 1,
|
||||
TCP_IOV_IP = 2,
|
||||
TCP_IOV_PAYLOAD = 3,
|
||||
TCP_NUM_IOVS
|
||||
};
|
||||
|
||||
extern char tcp_buf_discard [MAX_WINDOW];
|
||||
|
||||
void conn_flag_do(const struct ctx *c, struct tcp_tap_conn *conn,
|
||||
unsigned long flag);
|
||||
#define conn_flag(c, conn, flag) \
|
||||
do { \
|
||||
flow_trace(conn, "flag at %s:%i", __func__, __LINE__); \
|
||||
conn_flag_do(c, conn, flag); \
|
||||
} while (0)
|
||||
|
||||
|
||||
void conn_event_do(const struct ctx *c, struct tcp_tap_conn *conn,
|
||||
unsigned long event);
|
||||
#define conn_event(c, conn, event) \
|
||||
do { \
|
||||
flow_trace(conn, "event at %s:%i", __func__, __LINE__); \
|
||||
conn_event_do(c, conn, event); \
|
||||
} while (0)
|
||||
|
||||
void tcp_rst_do(struct ctx *c, struct tcp_tap_conn *conn);
|
||||
#define tcp_rst(c, conn) \
|
||||
do { \
|
||||
flow_dbg((conn), "TCP reset at %s:%i", __func__, __LINE__); \
|
||||
tcp_rst_do(c, conn); \
|
||||
} while (0)
|
||||
|
||||
size_t tcp_l2_buf_fill_headers(const struct ctx *c,
|
||||
const struct tcp_tap_conn *conn,
|
||||
struct iovec *iov, size_t dlen,
|
||||
const uint16_t *check, uint32_t seq);
|
||||
int tcp_update_seqack_wnd(const struct ctx *c, struct tcp_tap_conn *conn,
|
||||
int force_seq, struct tcp_info *tinfo);
|
||||
int tcp_prepare_flags(struct ctx *c, struct tcp_tap_conn *conn, int flags,
|
||||
struct tcphdr *th, char *data, size_t *optlen);
|
||||
|
||||
#endif /* TCP_INTERNAL_H */
|
||||
Loading…
Reference in New Issue
Block a user