123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719 |
- // SPDX-License-Identifier: GPL-2.0
- /*
- * Copyright 2017 Duncan Hare, all rights reserved.
- */
- /*
- * General Desription:
- *
- * TCP support for the wget command, for fast file downloading.
- *
- * HTTP/TCP Receiver:
- *
- * Prerequisites: - own ethernet address
- * - own IP address
- * - Server IP address
- * - Server with TCP
- * - TCP application (eg wget)
- * Next Step HTTPS?
- */
- #include <common.h>
- #include <command.h>
- #include <console.h>
- #include <env_internal.h>
- #include <errno.h>
- #include <net.h>
- #include <net/tcp.h>
- /*
- * TCP sliding window control used by us to request re-TX
- */
- static struct tcp_sack_v tcp_lost;
- /* TCP option timestamp */
- static u32 loc_timestamp;
- static u32 rmt_timestamp;
- static u32 tcp_seq_init;
- static u32 tcp_ack_edge;
- static int tcp_activity_count;
- /*
- * Search for TCP_SACK and review the comments before the code section
- * TCP_SACK is the number of packets at the front of the stream
- */
- enum pkt_state {PKT, NOPKT};
- struct sack_r {
- struct sack_edges se;
- enum pkt_state st;
- };
- static struct sack_r edge_a[TCP_SACK];
- static unsigned int sack_idx;
- static unsigned int prev_len;
- /*
- * TCP lengths are stored as a rounded up number of 32 bit words.
- * Add 3 to length round up, rounded, then divided into the
- * length in 32 bit words.
- */
- #define LEN_B_TO_DW(x) ((x) >> 2)
- #define ROUND_TCPHDR_LEN(x) (LEN_B_TO_DW((x) + 3))
- #define SHIFT_TO_TCPHDRLEN_FIELD(x) ((x) << 4)
- #define GET_TCP_HDR_LEN_IN_BYTES(x) ((x) >> 2)
- /* TCP connection state */
- static enum tcp_state current_tcp_state;
- /* Current TCP RX packet handler */
- static rxhand_tcp *tcp_packet_handler;
- /**
- * tcp_get_tcp_state() - get current TCP state
- *
- * Return: Current TCP state
- */
- enum tcp_state tcp_get_tcp_state(void)
- {
- return current_tcp_state;
- }
- /**
- * tcp_set_tcp_state() - set current TCP state
- * @new_state: new TCP state
- */
- void tcp_set_tcp_state(enum tcp_state new_state)
- {
- current_tcp_state = new_state;
- }
- static void dummy_handler(uchar *pkt, u16 dport,
- struct in_addr sip, u16 sport,
- u32 tcp_seq_num, u32 tcp_ack_num,
- u8 action, unsigned int len)
- {
- }
- /**
- * tcp_set_tcp_handler() - set a handler to receive data
- * @f: handler
- */
- void tcp_set_tcp_handler(rxhand_tcp *f)
- {
- debug_cond(DEBUG_INT_STATE, "--- net_loop TCP handler set (%p)\n", f);
- if (!f)
- tcp_packet_handler = dummy_handler;
- else
- tcp_packet_handler = f;
- }
- /**
- * tcp_set_pseudo_header() - set TCP pseudo header
- * @pkt: the packet
- * @src: source IP address
- * @dest: destinaion IP address
- * @tcp_len: tcp length
- * @pkt_len: packet length
- *
- * Return: the checksum of the packet
- */
- u16 tcp_set_pseudo_header(uchar *pkt, struct in_addr src, struct in_addr dest,
- int tcp_len, int pkt_len)
- {
- union tcp_build_pkt *b = (union tcp_build_pkt *)pkt;
- int checksum_len;
- /*
- * Pseudo header
- *
- * Zero the byte after the last byte so that the header checksum
- * will always work.
- */
- pkt[pkt_len] = 0;
- net_copy_ip((void *)&b->ph.p_src, &src);
- net_copy_ip((void *)&b->ph.p_dst, &dest);
- b->ph.rsvd = 0;
- b->ph.p = IPPROTO_TCP;
- b->ph.len = htons(tcp_len);
- checksum_len = tcp_len + PSEUDO_HDR_SIZE;
- debug_cond(DEBUG_DEV_PKT,
- "TCP Pesudo Header (to=%pI4, from=%pI4, Len=%d)\n",
- &b->ph.p_dst, &b->ph.p_src, checksum_len);
- return compute_ip_checksum(pkt + PSEUDO_PAD_SIZE, checksum_len);
- }
- /**
- * net_set_ack_options() - set TCP options in acknowledge packets
- * @b: the packet
- *
- * Return: TCP header length
- */
- int net_set_ack_options(union tcp_build_pkt *b)
- {
- b->sack.hdr.tcp_hlen = SHIFT_TO_TCPHDRLEN_FIELD(LEN_B_TO_DW(TCP_HDR_SIZE));
- b->sack.t_opt.kind = TCP_O_TS;
- b->sack.t_opt.len = TCP_OPT_LEN_A;
- b->sack.t_opt.t_snd = htons(loc_timestamp);
- b->sack.t_opt.t_rcv = rmt_timestamp;
- b->sack.sack_v.kind = TCP_1_NOP;
- b->sack.sack_v.len = 0;
- if (IS_ENABLED(CONFIG_PROT_TCP_SACK)) {
- if (tcp_lost.len > TCP_OPT_LEN_2) {
- debug_cond(DEBUG_DEV_PKT, "TCP ack opt lost.len %x\n",
- tcp_lost.len);
- b->sack.sack_v.len = tcp_lost.len;
- b->sack.sack_v.kind = TCP_V_SACK;
- b->sack.sack_v.hill[0].l = htonl(tcp_lost.hill[0].l);
- b->sack.sack_v.hill[0].r = htonl(tcp_lost.hill[0].r);
- /*
- * These SACK structures are initialized with NOPs to
- * provide TCP header alignment padding. There are 4
- * SACK structures used for both header padding and
- * internally.
- */
- b->sack.sack_v.hill[1].l = htonl(tcp_lost.hill[1].l);
- b->sack.sack_v.hill[1].r = htonl(tcp_lost.hill[1].r);
- b->sack.sack_v.hill[2].l = htonl(tcp_lost.hill[2].l);
- b->sack.sack_v.hill[2].r = htonl(tcp_lost.hill[2].r);
- b->sack.sack_v.hill[3].l = TCP_O_NOP;
- b->sack.sack_v.hill[3].r = TCP_O_NOP;
- }
- b->sack.hdr.tcp_hlen = SHIFT_TO_TCPHDRLEN_FIELD(ROUND_TCPHDR_LEN(TCP_HDR_SIZE +
- TCP_TSOPT_SIZE +
- tcp_lost.len));
- } else {
- b->sack.sack_v.kind = 0;
- b->sack.hdr.tcp_hlen = SHIFT_TO_TCPHDRLEN_FIELD(ROUND_TCPHDR_LEN(TCP_HDR_SIZE +
- TCP_TSOPT_SIZE));
- }
- /*
- * This returns the actual rounded up length of the
- * TCP header to add to the total packet length
- */
- return GET_TCP_HDR_LEN_IN_BYTES(b->sack.hdr.tcp_hlen);
- }
- /**
- * net_set_ack_options() - set TCP options in SYN packets
- * @b: the packet
- */
- void net_set_syn_options(union tcp_build_pkt *b)
- {
- if (IS_ENABLED(CONFIG_PROT_TCP_SACK))
- tcp_lost.len = 0;
- b->ip.hdr.tcp_hlen = 0xa0;
- b->ip.mss.kind = TCP_O_MSS;
- b->ip.mss.len = TCP_OPT_LEN_4;
- b->ip.mss.mss = htons(TCP_MSS);
- b->ip.scale.kind = TCP_O_SCL;
- b->ip.scale.scale = TCP_SCALE;
- b->ip.scale.len = TCP_OPT_LEN_3;
- if (IS_ENABLED(CONFIG_PROT_TCP_SACK)) {
- b->ip.sack_p.kind = TCP_P_SACK;
- b->ip.sack_p.len = TCP_OPT_LEN_2;
- } else {
- b->ip.sack_p.kind = TCP_1_NOP;
- b->ip.sack_p.len = TCP_1_NOP;
- }
- b->ip.t_opt.kind = TCP_O_TS;
- b->ip.t_opt.len = TCP_OPT_LEN_A;
- loc_timestamp = get_ticks();
- rmt_timestamp = 0;
- b->ip.t_opt.t_snd = 0;
- b->ip.t_opt.t_rcv = 0;
- b->ip.end = TCP_O_END;
- }
- int tcp_set_tcp_header(uchar *pkt, int dport, int sport, int payload_len,
- u8 action, u32 tcp_seq_num, u32 tcp_ack_num)
- {
- union tcp_build_pkt *b = (union tcp_build_pkt *)pkt;
- int pkt_hdr_len;
- int pkt_len;
- int tcp_len;
- /*
- * Header: 5 32 bit words. 4 bits TCP header Length,
- * 4 bits reserved options
- */
- b->ip.hdr.tcp_flags = action;
- pkt_hdr_len = IP_TCP_HDR_SIZE;
- b->ip.hdr.tcp_hlen = SHIFT_TO_TCPHDRLEN_FIELD(LEN_B_TO_DW(TCP_HDR_SIZE));
- switch (action) {
- case TCP_SYN:
- debug_cond(DEBUG_DEV_PKT,
- "TCP Hdr:SYN (%pI4, %pI4, sq=%u, ak=%u)\n",
- &net_server_ip, &net_ip,
- tcp_seq_num, tcp_ack_num);
- tcp_activity_count = 0;
- net_set_syn_options(b);
- tcp_seq_num = 0;
- tcp_ack_num = 0;
- pkt_hdr_len = IP_TCP_O_SIZE;
- if (current_tcp_state == TCP_SYN_SENT) { /* Too many SYNs */
- action = TCP_FIN;
- current_tcp_state = TCP_FIN_WAIT_1;
- } else {
- current_tcp_state = TCP_SYN_SENT;
- }
- break;
- case TCP_SYN | TCP_ACK:
- case TCP_ACK:
- pkt_hdr_len = IP_HDR_SIZE + net_set_ack_options(b);
- b->ip.hdr.tcp_flags = action;
- debug_cond(DEBUG_DEV_PKT,
- "TCP Hdr:ACK (%pI4, %pI4, s=%u, a=%u, A=%x)\n",
- &net_server_ip, &net_ip, tcp_seq_num, tcp_ack_num,
- action);
- break;
- case TCP_FIN:
- debug_cond(DEBUG_DEV_PKT,
- "TCP Hdr:FIN (%pI4, %pI4, s=%u, a=%u)\n",
- &net_server_ip, &net_ip, tcp_seq_num, tcp_ack_num);
- payload_len = 0;
- pkt_hdr_len = IP_TCP_HDR_SIZE;
- current_tcp_state = TCP_FIN_WAIT_1;
- break;
- case TCP_RST | TCP_ACK:
- case TCP_RST:
- debug_cond(DEBUG_DEV_PKT,
- "TCP Hdr:RST (%pI4, %pI4, s=%u, a=%u)\n",
- &net_server_ip, &net_ip, tcp_seq_num, tcp_ack_num);
- current_tcp_state = TCP_CLOSED;
- break;
- /* Notify connection closing */
- case (TCP_FIN | TCP_ACK):
- case (TCP_FIN | TCP_ACK | TCP_PUSH):
- if (current_tcp_state == TCP_CLOSE_WAIT)
- current_tcp_state = TCP_CLOSING;
- debug_cond(DEBUG_DEV_PKT,
- "TCP Hdr:FIN ACK PSH(%pI4, %pI4, s=%u, a=%u, A=%x)\n",
- &net_server_ip, &net_ip,
- tcp_seq_num, tcp_ack_num, action);
- fallthrough;
- default:
- pkt_hdr_len = IP_HDR_SIZE + net_set_ack_options(b);
- b->ip.hdr.tcp_flags = action | TCP_PUSH | TCP_ACK;
- debug_cond(DEBUG_DEV_PKT,
- "TCP Hdr:dft (%pI4, %pI4, s=%u, a=%u, A=%x)\n",
- &net_server_ip, &net_ip,
- tcp_seq_num, tcp_ack_num, action);
- }
- pkt_len = pkt_hdr_len + payload_len;
- tcp_len = pkt_len - IP_HDR_SIZE;
- tcp_ack_edge = tcp_ack_num;
- /* TCP Header */
- b->ip.hdr.tcp_ack = htonl(tcp_ack_edge);
- b->ip.hdr.tcp_src = htons(sport);
- b->ip.hdr.tcp_dst = htons(dport);
- b->ip.hdr.tcp_seq = htonl(tcp_seq_num);
- /*
- * TCP window size - TCP header variable tcp_win.
- * Change tcp_win only if you have an understanding of network
- * overrun, congestion, TCP segment sizes, TCP windows, TCP scale,
- * queuing theory and packet buffering. If there are too few buffers,
- * there will be data loss, recovery may work or the sending TCP,
- * the server, could abort the stream transmission.
- * MSS is governed by maximum Ethernet frame length.
- * The number of buffers is governed by the desire to have a queue of
- * full buffers to be processed at the destination to maximize
- * throughput. Temporary memory use for the boot phase on modern
- * SOCs is may not be considered a constraint to buffer space, if
- * it is, then the u-boot tftp or nfs kernel netboot should be
- * considered.
- */
- b->ip.hdr.tcp_win = htons(PKTBUFSRX * TCP_MSS >> TCP_SCALE);
- b->ip.hdr.tcp_xsum = 0;
- b->ip.hdr.tcp_ugr = 0;
- b->ip.hdr.tcp_xsum = tcp_set_pseudo_header(pkt, net_ip, net_server_ip,
- tcp_len, pkt_len);
- net_set_ip_header((uchar *)&b->ip, net_server_ip, net_ip,
- pkt_len, IPPROTO_TCP);
- return pkt_hdr_len;
- }
- /**
- * tcp_hole() - Selective Acknowledgment (Essential for fast stream transfer)
- * @tcp_seq_num: TCP sequence start number
- * @len: the length of sequence numbers
- */
- void tcp_hole(u32 tcp_seq_num, u32 len)
- {
- u32 idx_sack, sack_in;
- u32 sack_end = TCP_SACK - 1;
- u32 hill = 0;
- enum pkt_state expect = PKT;
- u32 seq = tcp_seq_num - tcp_seq_init;
- u32 hol_l = tcp_ack_edge - tcp_seq_init;
- u32 hol_r = 0;
- /* Place new seq number in correct place in receive array */
- if (prev_len == 0)
- prev_len = len;
- idx_sack = sack_idx + ((tcp_seq_num - tcp_ack_edge) / prev_len);
- if (idx_sack < TCP_SACK) {
- edge_a[idx_sack].se.l = tcp_seq_num;
- edge_a[idx_sack].se.r = tcp_seq_num + len;
- edge_a[idx_sack].st = PKT;
- /*
- * The fin (last) packet is not the same length as data
- * packets, and if it's length is recorded and used for
- * array index calculation, calculation breaks.
- */
- if (prev_len < len)
- prev_len = len;
- }
- debug_cond(DEBUG_DEV_PKT,
- "TCP 1 seq %d, edg %d, len %d, sack_idx %d, sack_end %d\n",
- seq, hol_l, len, sack_idx, sack_end);
- /* Right edge of contiguous stream, is the left edge of first hill */
- hol_l = tcp_seq_num - tcp_seq_init;
- hol_r = hol_l + len;
- if (IS_ENABLED(CONFIG_PROT_TCP_SACK))
- tcp_lost.len = TCP_OPT_LEN_2;
- debug_cond(DEBUG_DEV_PKT,
- "TCP 1 in %d, seq %d, pkt_l %d, pkt_r %d, sack_idx %d, sack_end %d\n",
- idx_sack, seq, hol_l, hol_r, sack_idx, sack_end);
- for (sack_in = sack_idx; sack_in < sack_end && hill < TCP_SACK_HILLS;
- sack_in++) {
- switch (expect) {
- case NOPKT:
- switch (edge_a[sack_in].st) {
- case NOPKT:
- debug_cond(DEBUG_INT_STATE, "N");
- break;
- case PKT:
- debug_cond(DEBUG_INT_STATE, "n");
- if (IS_ENABLED(CONFIG_PROT_TCP_SACK)) {
- tcp_lost.hill[hill].l =
- edge_a[sack_in].se.l;
- tcp_lost.hill[hill].r =
- edge_a[sack_in].se.r;
- }
- expect = PKT;
- break;
- }
- break;
- case PKT:
- switch (edge_a[sack_in].st) {
- case NOPKT:
- debug_cond(DEBUG_INT_STATE, "p");
- if (sack_in > sack_idx &&
- hill < TCP_SACK_HILLS) {
- hill++;
- if (IS_ENABLED(CONFIG_PROT_TCP_SACK))
- tcp_lost.len += TCP_OPT_LEN_8;
- }
- expect = NOPKT;
- break;
- case PKT:
- debug_cond(DEBUG_INT_STATE, "P");
- if (tcp_ack_edge == edge_a[sack_in].se.l) {
- tcp_ack_edge = edge_a[sack_in].se.r;
- edge_a[sack_in].st = NOPKT;
- sack_idx++;
- } else {
- if (IS_ENABLED(CONFIG_PROT_TCP_SACK) &&
- hill < TCP_SACK_HILLS)
- tcp_lost.hill[hill].r =
- edge_a[sack_in].se.r;
- if (IS_ENABLED(CONFIG_PROT_TCP_SACK) &&
- sack_in == sack_end - 1)
- tcp_lost.hill[hill].r =
- edge_a[sack_in].se.r;
- }
- break;
- }
- break;
- }
- }
- debug_cond(DEBUG_INT_STATE, "\n");
- if (!IS_ENABLED(CONFIG_PROT_TCP_SACK) || tcp_lost.len <= TCP_OPT_LEN_2)
- sack_idx = 0;
- }
- /**
- * tcp_parse_options() - parsing TCP options
- * @o: pointer to the option field.
- * @o_len: length of the option field.
- */
- void tcp_parse_options(uchar *o, int o_len)
- {
- struct tcp_t_opt *tsopt;
- uchar *p = o;
- /*
- * NOPs are options with a zero length, and thus are special.
- * All other options have length fields.
- */
- for (p = o; p < (o + o_len); p = p + p[1]) {
- if (!p[1])
- return; /* Finished processing options */
- switch (p[0]) {
- case TCP_O_END:
- return;
- case TCP_O_MSS:
- case TCP_O_SCL:
- case TCP_P_SACK:
- case TCP_V_SACK:
- break;
- case TCP_O_TS:
- tsopt = (struct tcp_t_opt *)p;
- rmt_timestamp = tsopt->t_snd;
- return;
- }
- /* Process optional NOPs */
- if (p[0] == TCP_O_NOP)
- p++;
- }
- }
- static u8 tcp_state_machine(u8 tcp_flags, u32 tcp_seq_num, int payload_len)
- {
- u8 tcp_fin = tcp_flags & TCP_FIN;
- u8 tcp_syn = tcp_flags & TCP_SYN;
- u8 tcp_rst = tcp_flags & TCP_RST;
- u8 tcp_push = tcp_flags & TCP_PUSH;
- u8 tcp_ack = tcp_flags & TCP_ACK;
- u8 action = TCP_DATA;
- int i;
- /*
- * tcp_flags are examined to determine TX action in a given state
- * tcp_push is interpreted to mean "inform the app"
- * urg, ece, cer and nonce flags are not supported.
- *
- * exe and crw are use to signal and confirm knowledge of congestion.
- * This TCP only sends a file request and acks. If it generates
- * congestion, the network is broken.
- */
- debug_cond(DEBUG_INT_STATE, "TCP STATE ENTRY %x\n", action);
- if (tcp_rst) {
- action = TCP_DATA;
- current_tcp_state = TCP_CLOSED;
- net_set_state(NETLOOP_FAIL);
- debug_cond(DEBUG_INT_STATE, "TCP Reset %x\n", tcp_flags);
- return TCP_RST;
- }
- switch (current_tcp_state) {
- case TCP_CLOSED:
- debug_cond(DEBUG_INT_STATE, "TCP CLOSED %x\n", tcp_flags);
- if (tcp_syn) {
- action = TCP_SYN | TCP_ACK;
- tcp_seq_init = tcp_seq_num;
- tcp_ack_edge = tcp_seq_num + 1;
- current_tcp_state = TCP_SYN_RECEIVED;
- } else if (tcp_ack || tcp_fin) {
- action = TCP_DATA;
- }
- break;
- case TCP_SYN_RECEIVED:
- case TCP_SYN_SENT:
- debug_cond(DEBUG_INT_STATE, "TCP_SYN_SENT | TCP_SYN_RECEIVED %x, %u\n",
- tcp_flags, tcp_seq_num);
- if (tcp_fin) {
- action = action | TCP_PUSH;
- current_tcp_state = TCP_CLOSE_WAIT;
- } else if (tcp_ack || (tcp_syn && tcp_ack)) {
- action |= TCP_ACK;
- tcp_seq_init = tcp_seq_num;
- tcp_ack_edge = tcp_seq_num + 1;
- sack_idx = 0;
- edge_a[sack_idx].se.l = tcp_ack_edge;
- edge_a[sack_idx].se.r = tcp_ack_edge;
- prev_len = 0;
- current_tcp_state = TCP_ESTABLISHED;
- for (i = 0; i < TCP_SACK; i++)
- edge_a[i].st = NOPKT;
- if (tcp_syn && tcp_ack)
- action |= TCP_PUSH;
- } else {
- action = TCP_DATA;
- }
- break;
- case TCP_ESTABLISHED:
- debug_cond(DEBUG_INT_STATE, "TCP_ESTABLISHED %x\n", tcp_flags);
- if (payload_len > 0) {
- tcp_hole(tcp_seq_num, payload_len);
- tcp_fin = TCP_DATA; /* cause standalone FIN */
- }
- if ((tcp_fin) &&
- (!IS_ENABLED(CONFIG_PROT_TCP_SACK) ||
- tcp_lost.len <= TCP_OPT_LEN_2)) {
- action = action | TCP_FIN | TCP_PUSH | TCP_ACK;
- current_tcp_state = TCP_CLOSE_WAIT;
- } else if (tcp_ack) {
- action = TCP_DATA;
- }
- if (tcp_syn)
- action = TCP_ACK + TCP_RST;
- else if (tcp_push)
- action = action | TCP_PUSH;
- break;
- case TCP_CLOSE_WAIT:
- debug_cond(DEBUG_INT_STATE, "TCP_CLOSE_WAIT (%x)\n", tcp_flags);
- action = TCP_DATA;
- break;
- case TCP_FIN_WAIT_2:
- debug_cond(DEBUG_INT_STATE, "TCP_FIN_WAIT_2 (%x)\n", tcp_flags);
- if (tcp_ack) {
- action = TCP_PUSH | TCP_ACK;
- current_tcp_state = TCP_CLOSED;
- puts("\n");
- } else if (tcp_syn) {
- action = TCP_DATA;
- } else if (tcp_fin) {
- action = TCP_DATA;
- }
- break;
- case TCP_FIN_WAIT_1:
- debug_cond(DEBUG_INT_STATE, "TCP_FIN_WAIT_1 (%x)\n", tcp_flags);
- if (tcp_fin) {
- tcp_ack_edge++;
- action = TCP_ACK | TCP_FIN;
- current_tcp_state = TCP_FIN_WAIT_2;
- }
- if (tcp_syn)
- action = TCP_RST;
- if (tcp_ack)
- current_tcp_state = TCP_CLOSED;
- break;
- case TCP_CLOSING:
- debug_cond(DEBUG_INT_STATE, "TCP_CLOSING (%x)\n", tcp_flags);
- if (tcp_ack) {
- action = TCP_PUSH;
- current_tcp_state = TCP_CLOSED;
- puts("\n");
- } else if (tcp_syn) {
- action = TCP_RST;
- } else if (tcp_fin) {
- action = TCP_DATA;
- }
- break;
- }
- return action;
- }
- /**
- * rxhand_tcp_f() - process receiving data and call data handler.
- * @b: the packet
- * @pkt_len: the length of packet.
- */
- void rxhand_tcp_f(union tcp_build_pkt *b, unsigned int pkt_len)
- {
- int tcp_len = pkt_len - IP_HDR_SIZE;
- u16 tcp_rx_xsum = b->ip.hdr.ip_sum;
- u8 tcp_action = TCP_DATA;
- u32 tcp_seq_num, tcp_ack_num;
- int tcp_hdr_len, payload_len;
- /* Verify IP header */
- debug_cond(DEBUG_DEV_PKT,
- "TCP RX in RX Sum (to=%pI4, from=%pI4, len=%d)\n",
- &b->ip.hdr.ip_src, &b->ip.hdr.ip_dst, pkt_len);
- b->ip.hdr.ip_src = net_server_ip;
- b->ip.hdr.ip_dst = net_ip;
- b->ip.hdr.ip_sum = 0;
- if (tcp_rx_xsum != compute_ip_checksum(b, IP_HDR_SIZE)) {
- debug_cond(DEBUG_DEV_PKT,
- "TCP RX IP xSum Error (%pI4, =%pI4, len=%d)\n",
- &net_ip, &net_server_ip, pkt_len);
- return;
- }
- /* Build pseudo header and verify TCP header */
- tcp_rx_xsum = b->ip.hdr.tcp_xsum;
- b->ip.hdr.tcp_xsum = 0;
- if (tcp_rx_xsum != tcp_set_pseudo_header((uchar *)b, b->ip.hdr.ip_src,
- b->ip.hdr.ip_dst, tcp_len,
- pkt_len)) {
- debug_cond(DEBUG_DEV_PKT,
- "TCP RX TCP xSum Error (%pI4, %pI4, len=%d)\n",
- &net_ip, &net_server_ip, tcp_len);
- return;
- }
- tcp_hdr_len = GET_TCP_HDR_LEN_IN_BYTES(b->ip.hdr.tcp_hlen);
- payload_len = tcp_len - tcp_hdr_len;
- if (tcp_hdr_len > TCP_HDR_SIZE)
- tcp_parse_options((uchar *)b + IP_TCP_HDR_SIZE,
- tcp_hdr_len - TCP_HDR_SIZE);
- /*
- * Incoming sequence and ack numbers are server's view of the numbers.
- * The app must swap the numbers when responding.
- */
- tcp_seq_num = ntohl(b->ip.hdr.tcp_seq);
- tcp_ack_num = ntohl(b->ip.hdr.tcp_ack);
- /* Packets are not ordered. Send to app as received. */
- tcp_action = tcp_state_machine(b->ip.hdr.tcp_flags,
- tcp_seq_num, payload_len);
- tcp_activity_count++;
- if (tcp_activity_count > TCP_ACTIVITY) {
- puts("| ");
- tcp_activity_count = 0;
- }
- if ((tcp_action & TCP_PUSH) || payload_len > 0) {
- debug_cond(DEBUG_DEV_PKT,
- "TCP Notify (action=%x, Seq=%u,Ack=%u,Pay%d)\n",
- tcp_action, tcp_seq_num, tcp_ack_num, payload_len);
- (*tcp_packet_handler) ((uchar *)b + pkt_len - payload_len, b->ip.hdr.tcp_dst,
- b->ip.hdr.ip_src, b->ip.hdr.tcp_src, tcp_seq_num,
- tcp_ack_num, tcp_action, payload_len);
- } else if (tcp_action != TCP_DATA) {
- debug_cond(DEBUG_DEV_PKT,
- "TCP Action (action=%x,Seq=%u,Ack=%u,Pay=%d)\n",
- tcp_action, tcp_ack_num, tcp_ack_edge, payload_len);
- /*
- * Warning: Incoming Ack & Seq sequence numbers are transposed
- * here to outgoing Seq & Ack sequence numbers
- */
- net_send_tcp_packet(0, ntohs(b->ip.hdr.tcp_src),
- ntohs(b->ip.hdr.tcp_dst),
- (tcp_action & (~TCP_PUSH)),
- tcp_ack_num, tcp_ack_edge);
- }
- }
|