diff options
Diffstat (limited to 'lib/lufa/Projects/Webserver/Lib/uip/uip.c')
| -rw-r--r-- | lib/lufa/Projects/Webserver/Lib/uip/uip.c | 1941 |
1 files changed, 0 insertions, 1941 deletions
diff --git a/lib/lufa/Projects/Webserver/Lib/uip/uip.c b/lib/lufa/Projects/Webserver/Lib/uip/uip.c deleted file mode 100644 index fead75775c..0000000000 --- a/lib/lufa/Projects/Webserver/Lib/uip/uip.c +++ /dev/null @@ -1,1941 +0,0 @@ -#define DEBUG_PRINTF(...) /*printf(__VA_ARGS__)*/ - -/** - * \addtogroup uip - * @{ - */ - -/** - * \file - * The uIP TCP/IP stack code. - * \author Adam Dunkels <adam@dunkels.com> - */ - -/* - * Copyright (c) 2001-2003, Adam Dunkels. - * All rights reserved. - * - * 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. - * 3. The name of the author may not be used to endorse or promote - * products derived from this software without specific prior - * written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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. - * - * This file is part of the uIP TCP/IP stack. - * - * $Id: uip.c,v 1.15 2008/10/15 08:08:32 adamdunkels Exp $ - * - */ - -/* - * uIP is a small implementation of the IP, UDP and TCP protocols (as - * well as some basic ICMP stuff). The implementation couples the IP, - * UDP, TCP and the application layers very tightly. To keep the size - * of the compiled code down, this code frequently uses the goto - * statement. While it would be possible to break the uip_process() - * function into many smaller functions, this would increase the code - * size because of the overhead of parameter passing and the fact that - * the optimizer would not be as efficient. - * - * The principle is that we have a small buffer, called the uip_buf, - * in which the device driver puts an incoming packet. The TCP/IP - * stack parses the headers in the packet, and calls the - * application. If the remote host has sent data to the application, - * this data is present in the uip_buf and the application read the - * data from there. It is up to the application to put this data into - * a byte stream if needed. The application will not be fed with data - * that is out of sequence. - * - * If the application whishes to send data to the peer, it should put - * its data into the uip_buf. The uip_appdata pointer points to the - * first available byte. The TCP/IP stack will calculate the - * checksums, and fill in the necessary header fields and finally send - * the packet back to the peer. -*/ - -#include "uip.h" -#include "uipopt.h" -#include "uip_arp.h" - -#if !UIP_CONF_IPV6 /* If UIP_CONF_IPV6 is defined, we compile the - uip6.c file instead of this one. Therefore - this #ifndef removes the entire compilation - output of the uip.c file */ - - -#if UIP_CONF_IPV6 -#include "net/uip-neighbor.h" -#endif /* UIP_CONF_IPV6 */ - -#include <string.h> - -/*---------------------------------------------------------------------------*/ -/* Variable definitions. */ - - -/* The IP address of this host. If it is defined to be fixed (by - setting UIP_FIXEDADDR to 1 in uipopt.h), the address is set - here. Otherwise, the address */ -#if UIP_FIXEDADDR > 0 -const uip_ipaddr_t uip_hostaddr = - { UIP_IPADDR0, UIP_IPADDR1, UIP_IPADDR2, UIP_IPADDR3 }; -const uip_ipaddr_t uip_draddr = - { UIP_DRIPADDR0, UIP_DRIPADDR1, UIP_DRIPADDR2, UIP_DRIPADDR3 }; -const uip_ipaddr_t uip_netmask = - { UIP_NETMASK0, UIP_NETMASK1, UIP_NETMASK2, UIP_NETMASK3 }; -#else -uip_ipaddr_t uip_hostaddr, uip_draddr, uip_netmask; -#endif /* UIP_FIXEDADDR */ - -const uip_ipaddr_t uip_broadcast_addr = -#if UIP_CONF_IPV6 - { { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, - 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff } }; -#else /* UIP_CONF_IPV6 */ - { { 0xff, 0xff, 0xff, 0xff } }; -#endif /* UIP_CONF_IPV6 */ -const uip_ipaddr_t uip_all_zeroes_addr = { { 0x0, /* rest is 0 */ } }; - -#if UIP_FIXEDETHADDR -const struct uip_eth_addr uip_ethaddr = {{UIP_ETHADDR0, - UIP_ETHADDR1, - UIP_ETHADDR2, - UIP_ETHADDR3, - UIP_ETHADDR4, - UIP_ETHADDR5}}; -#else -struct uip_eth_addr uip_ethaddr = {{0,0,0,0,0,0}}; -#endif - -#ifndef UIP_CONF_EXTERNAL_BUFFER -u8_t uip_buf[UIP_BUFSIZE + 2]; /* The packet buffer that contains - incoming packets. */ -#endif /* UIP_CONF_EXTERNAL_BUFFER */ - -void *uip_appdata; /* The uip_appdata pointer points to - application data. */ -void *uip_sappdata; /* The uip_appdata pointer points to - the application data which is to - be sent. */ -#if UIP_URGDATA > 0 -void *uip_urgdata; /* The uip_urgdata pointer points to - urgent data (out-of-band data), if - present. */ -u16_t uip_urglen, uip_surglen; -#endif /* UIP_URGDATA > 0 */ - -u16_t uip_len, uip_slen; - /* The uip_len is either 8 or 16 bits, - depending on the maximum packet - size. */ - -u8_t uip_flags; /* The uip_flags variable is used for - communication between the TCP/IP stack - and the application program. */ -struct uip_conn *uip_conn; /* uip_conn always points to the current - connection. */ - -struct uip_conn uip_conns[UIP_CONNS]; - /* The uip_conns array holds all TCP - connections. */ -u16_t uip_listenports[UIP_LISTENPORTS]; - /* The uip_listenports list all currently - listening ports. */ -#if UIP_UDP -struct uip_udp_conn *uip_udp_conn; -struct uip_udp_conn uip_udp_conns[UIP_UDP_CONNS]; -#endif /* UIP_UDP */ - -static u16_t ipid; /* Ths ipid variable is an increasing - number that is used for the IP ID - field. */ - -void uip_setipid(u16_t id) { ipid = id; } - -static u8_t iss[4]; /* The iss variable is used for the TCP - initial sequence number. */ - -#if UIP_ACTIVE_OPEN -static u16_t lastport; /* Keeps track of the last port used for - a new connection. */ -#endif /* UIP_ACTIVE_OPEN */ - -/* Temporary variables. */ -u8_t uip_acc32[4]; -static u8_t c, opt; -static u16_t tmp16; - -/* Structures and definitions. */ -#define TCP_FIN 0x01 -#define TCP_SYN 0x02 -#define TCP_RST 0x04 -#define TCP_PSH 0x08 -#define TCP_ACK 0x10 -#define TCP_URG 0x20 -#define TCP_CTL 0x3f - -#define TCP_OPT_END 0 /* End of TCP options list */ -#define TCP_OPT_NOOP 1 /* "No-operation" TCP option */ -#define TCP_OPT_MSS 2 /* Maximum segment size TCP option */ - -#define TCP_OPT_MSS_LEN 4 /* Length of TCP MSS option. */ - -#define ICMP_ECHO_REPLY 0 -#define ICMP_ECHO 8 - -#define ICMP_DEST_UNREACHABLE 3 -#define ICMP_PORT_UNREACHABLE 3 - -#define ICMP6_ECHO_REPLY 129 -#define ICMP6_ECHO 128 -#define ICMP6_NEIGHBOR_SOLICITATION 135 -#define ICMP6_NEIGHBOR_ADVERTISEMENT 136 - -#define ICMP6_FLAG_S (1 << 6) - -#define ICMP6_OPTION_SOURCE_LINK_ADDRESS 1 -#define ICMP6_OPTION_TARGET_LINK_ADDRESS 2 - - -/* Macros. */ -#define BUF ((struct uip_tcpip_hdr *)&uip_buf[UIP_LLH_LEN]) -#define FBUF ((struct uip_tcpip_hdr *)&uip_reassbuf[0]) -#define ICMPBUF ((struct uip_icmpip_hdr *)&uip_buf[UIP_LLH_LEN]) -#define UDPBUF ((struct uip_udpip_hdr *)&uip_buf[UIP_LLH_LEN]) - - -#if UIP_STATISTICS == 1 -struct uip_stats uip_stat; -#define UIP_STAT(s) s -#else -#define UIP_STAT(s) -#endif /* UIP_STATISTICS == 1 */ - -#if UIP_LOGGING == 1 -#include <stdio.h> -void uip_log(char *msg); -#define UIP_LOG(m) uip_log(m) -#else -#define UIP_LOG(m) -#endif /* UIP_LOGGING == 1 */ - -#if ! UIP_ARCH_ADD32 -void -uip_add32(u8_t *op32, u16_t op16) -{ - uip_acc32[3] = op32[3] + (op16 & 0xff); - uip_acc32[2] = op32[2] + (op16 >> 8); - uip_acc32[1] = op32[1]; - uip_acc32[0] = op32[0]; - - if(uip_acc32[2] < (op16 >> 8)) { - ++uip_acc32[1]; - if(uip_acc32[1] == 0) { - ++uip_acc32[0]; - } - } - - - if(uip_acc32[3] < (op16 & 0xff)) { - ++uip_acc32[2]; - if(uip_acc32[2] == 0) { - ++uip_acc32[1]; - if(uip_acc32[1] == 0) { - ++uip_acc32[0]; - } - } - } -} - -#endif /* UIP_ARCH_ADD32 */ - -#if ! UIP_ARCH_CHKSUM -/*---------------------------------------------------------------------------*/ -static u16_t -chksum(u16_t sum, const u8_t *data, u16_t len) -{ - u16_t t; - const u8_t *dataptr; - const u8_t *last_byte; - - dataptr = data; - last_byte = data + len - 1; - - while(dataptr < last_byte) { /* At least two more bytes */ - t = (dataptr[0] << 8) + dataptr[1]; - sum += t; - if(sum < t) { - sum++; /* carry */ - } - dataptr += 2; - } - - if(dataptr == last_byte) { - t = (dataptr[0] << 8) + 0; - sum += t; - if(sum < t) { - sum++; /* carry */ - } - } - - /* Return sum in host byte order. */ - return sum; -} -/*---------------------------------------------------------------------------*/ -u16_t -uip_chksum(u16_t *data, u16_t len) -{ - return htons(chksum(0, (u8_t *)data, len)); -} -/*---------------------------------------------------------------------------*/ -#ifndef UIP_ARCH_IPCHKSUM -u16_t -uip_ipchksum(void) -{ - u16_t sum; - - sum = chksum(0, &uip_buf[UIP_LLH_LEN], UIP_IPH_LEN); - DEBUG_PRINTF("uip_ipchksum: sum 0x%04x\n", sum); - return (sum == 0) ? 0xffff : htons(sum); -} -#endif -/*---------------------------------------------------------------------------*/ -static u16_t -upper_layer_chksum(u8_t proto) -{ - u16_t upper_layer_len; - u16_t sum; - -#if UIP_CONF_IPV6 - upper_layer_len = (((u16_t)(BUF->len[0]) << 8) + BUF->len[1]); -#else /* UIP_CONF_IPV6 */ - upper_layer_len = (((u16_t)(BUF->len[0]) << 8) + BUF->len[1]) - UIP_IPH_LEN; -#endif /* UIP_CONF_IPV6 */ - - /* First sum pseudo-header. */ - - /* IP protocol and length fields. This addition cannot carry. */ - sum = upper_layer_len + proto; - /* Sum IP source and destination addresses. */ - sum = chksum(sum, (u8_t *)&BUF->srcipaddr, 2 * sizeof(uip_ipaddr_t)); - - /* Sum TCP header and data. */ - sum = chksum(sum, &uip_buf[UIP_IPH_LEN + UIP_LLH_LEN], - upper_layer_len); - - return (sum == 0) ? 0xffff : htons(sum); -} -/*---------------------------------------------------------------------------*/ -#if UIP_CONF_IPV6 -u16_t -uip_icmp6chksum(void) -{ - return upper_layer_chksum(UIP_PROTO_ICMP6); - -} -#endif /* UIP_CONF_IPV6 */ -/*---------------------------------------------------------------------------*/ -u16_t -uip_tcpchksum(void) -{ - return upper_layer_chksum(UIP_PROTO_TCP); -} -/*---------------------------------------------------------------------------*/ -#if UIP_UDP_CHECKSUMS -u16_t -uip_udpchksum(void) -{ - return upper_layer_chksum(UIP_PROTO_UDP); -} -#endif /* UIP_UDP_CHECKSUMS */ -#endif /* UIP_ARCH_CHKSUM */ -/*---------------------------------------------------------------------------*/ -void -uip_init(void) -{ - for(c = 0; c < UIP_LISTENPORTS; ++c) { - uip_listenports[c] = 0; - } - for(c = 0; c < UIP_CONNS; ++c) { - uip_conns[c].tcpstateflags = UIP_CLOSED; - } -#if UIP_ACTIVE_OPEN - lastport = 1024; -#endif /* UIP_ACTIVE_OPEN */ - -#if UIP_UDP - for(c = 0; c < UIP_UDP_CONNS; ++c) { - uip_udp_conns[c].lport = 0; - } -#endif /* UIP_UDP */ - - - /* IPv4 initialization. */ -#if UIP_FIXEDADDR == 0 - /* uip_hostaddr[0] = uip_hostaddr[1] = 0;*/ -#endif /* UIP_FIXEDADDR */ - -} -/*---------------------------------------------------------------------------*/ -#if UIP_ACTIVE_OPEN -struct uip_conn * -uip_connect(uip_ipaddr_t *ripaddr, u16_t rport) -{ - register struct uip_conn *conn, *cconn; - - /* Find an unused local port. */ - again: - ++lastport; - - if(lastport >= 32000) { - lastport = 4096; - } - - /* Check if this port is already in use, and if so try to find - another one. */ - for(c = 0; c < UIP_CONNS; ++c) { - conn = &uip_conns[c]; - if(conn->tcpstateflags != UIP_CLOSED && - conn->lport == htons(lastport)) { - goto again; - } - } - - conn = 0; - for(c = 0; c < UIP_CONNS; ++c) { - cconn = &uip_conns[c]; - if(cconn->tcpstateflags == UIP_CLOSED) { - conn = cconn; - break; - } - if(cconn->tcpstateflags == UIP_TIME_WAIT) { - if(conn == 0 || - cconn->timer > conn->timer) { - conn = cconn; - } - } - } - - if(conn == 0) { - return 0; - } - - conn->tcpstateflags = UIP_SYN_SENT; - - conn->snd_nxt[0] = iss[0]; - conn->snd_nxt[1] = iss[1]; - conn->snd_nxt[2] = iss[2]; - conn->snd_nxt[3] = iss[3]; - - conn->initialmss = conn->mss = UIP_TCP_MSS; - - conn->len = 1; /* TCP length of the SYN is one. */ - conn->nrtx = 0; - conn->timer = 1; /* Send the SYN next time around. */ - conn->rto = UIP_RTO; - conn->sa = 0; - conn->sv = 16; /* Initial value of the RTT variance. */ - conn->lport = htons(lastport); - conn->rport = rport; - uip_ipaddr_copy(&conn->ripaddr, ripaddr); - - return conn; -} -#endif /* UIP_ACTIVE_OPEN */ -/*---------------------------------------------------------------------------*/ -#if UIP_UDP -struct uip_udp_conn * -uip_udp_new(const uip_ipaddr_t *ripaddr, u16_t rport) -{ - register struct uip_udp_conn *conn; - - /* Find an unused local port. */ - again: - ++lastport; - - if(lastport >= 32000) { - lastport = 4096; - } - - for(c = 0; c < UIP_UDP_CONNS; ++c) { - if(uip_udp_conns[c].lport == htons(lastport)) { - goto again; - } - } - - - conn = 0; - for(c = 0; c < UIP_UDP_CONNS; ++c) { - if(uip_udp_conns[c].lport == 0) { - conn = &uip_udp_conns[c]; - break; - } - } - - if(conn == 0) { - return 0; - } - - conn->lport = HTONS(lastport); - conn->rport = rport; - if(ripaddr == NULL) { - memset(&conn->ripaddr, 0, sizeof(uip_ipaddr_t)); - } else { - uip_ipaddr_copy(&conn->ripaddr, ripaddr); - } - conn->ttl = UIP_TTL; - - return conn; -} -#endif /* UIP_UDP */ -/*---------------------------------------------------------------------------*/ -void -uip_unlisten(u16_t port) -{ - for(c = 0; c < UIP_LISTENPORTS; ++c) { - if(uip_listenports[c] == port) { - uip_listenports[c] = 0; - return; - } - } -} -/*---------------------------------------------------------------------------*/ -void -uip_listen(u16_t port) -{ - for(c = 0; c < UIP_LISTENPORTS; ++c) { - if(uip_listenports[c] == 0) { - uip_listenports[c] = port; - return; - } - } -} -/*---------------------------------------------------------------------------*/ -/* XXX: IP fragment reassembly: not well-tested. */ - -#if UIP_REASSEMBLY && !UIP_CONF_IPV6 -#define UIP_REASS_BUFSIZE (UIP_BUFSIZE - UIP_LLH_LEN) -static u8_t uip_reassbuf[UIP_REASS_BUFSIZE]; -static u8_t uip_reassbitmap[UIP_REASS_BUFSIZE / (8 * 8)]; -static const u8_t bitmap_bits[8] = {0xff, 0x7f, 0x3f, 0x1f, - 0x0f, 0x07, 0x03, 0x01}; -static u16_t uip_reasslen; -static u8_t uip_reassflags; -#define UIP_REASS_FLAG_LASTFRAG 0x01 -static u8_t uip_reasstmr; - -#define IP_MF 0x20 - -static u8_t -uip_reass(void) -{ - u16_t offset, len; - u16_t i; - - /* If ip_reasstmr is zero, no packet is present in the buffer, so we - write the IP header of the fragment into the reassembly - buffer. The timer is updated with the maximum age. */ - if(uip_reasstmr == 0) { - memcpy(uip_reassbuf, &BUF->vhl, UIP_IPH_LEN); - uip_reasstmr = UIP_REASS_MAXAGE; - uip_reassflags = 0; - /* Clear the bitmap. */ - memset(uip_reassbitmap, 0, sizeof(uip_reassbitmap)); - } - - /* Check if the incoming fragment matches the one currently present - in the reasembly buffer. If so, we proceed with copying the - fragment into the buffer. */ - if(BUF->srcipaddr[0] == FBUF->srcipaddr[0] && - BUF->srcipaddr[1] == FBUF->srcipaddr[1] && - BUF->destipaddr[0] == FBUF->destipaddr[0] && - BUF->destipaddr[1] == FBUF->destipaddr[1] && - BUF->ipid[0] == FBUF->ipid[0] && - BUF->ipid[1] == FBUF->ipid[1]) { - - len = (BUF->len[0] << 8) + BUF->len[1] - (BUF->vhl & 0x0f) * 4; - offset = (((BUF->ipoffset[0] & 0x3f) << 8) + BUF->ipoffset[1]) * 8; - - /* If the offset or the offset + fragment length overflows the - reassembly buffer, we discard the entire packet. */ - if(offset > UIP_REASS_BUFSIZE || - offset + len > UIP_REASS_BUFSIZE) { - uip_reasstmr = 0; - goto nullreturn; - } - - /* Copy the fragment into the reassembly buffer, at the right - offset. */ - memcpy(&uip_reassbuf[UIP_IPH_LEN + offset], - (char *)BUF + (int)((BUF->vhl & 0x0f) * 4), - len); - - /* Update the bitmap. */ - if(offset / (8 * 8) == (offset + len) / (8 * 8)) { - /* If the two endpoints are in the same byte, we only update - that byte. */ - - uip_reassbitmap[offset / (8 * 8)] |= - bitmap_bits[(offset / 8 ) & 7] & - ~bitmap_bits[((offset + len) / 8 ) & 7]; - } else { - /* If the two endpoints are in different bytes, we update the - bytes in the endpoints and fill the stuff in-between with - 0xff. */ - uip_reassbitmap[offset / (8 * 8)] |= - bitmap_bits[(offset / 8 ) & 7]; - for(i = 1 + offset / (8 * 8); i < (offset + len) / (8 * 8); ++i) { - uip_reassbitmap[i] = 0xff; - } - uip_reassbitmap[(offset + len) / (8 * 8)] |= - ~bitmap_bits[((offset + len) / 8 ) & 7]; - } - - /* If this fragment has the More Fragments flag set to zero, we - know that this is the last fragment, so we can calculate the - size of the entire packet. We also set the - IP_REASS_FLAG_LASTFRAG flag to indicate that we have received - the final fragment. */ - - if((BUF->ipoffset[0] & IP_MF) == 0) { - uip_reassflags |= UIP_REASS_FLAG_LASTFRAG; - uip_reasslen = offset + len; - } - - /* Finally, we check if we have a full packet in the buffer. We do - this by checking if we have the last fragment and if all bits - in the bitmap are set. */ - if(uip_reassflags & UIP_REASS_FLAG_LASTFRAG) { - /* Check all bytes up to and including all but the last byte in - the bitmap. */ - for(i = 0; i < uip_reasslen / (8 * 8) - 1; ++i) { - if(uip_reassbitmap[i] != 0xff) { - goto nullreturn; - } - } - /* Check the last byte in the bitmap. It should contain just the - right amount of bits. */ - if(uip_reassbitmap[uip_reasslen / (8 * 8)] != - (u8_t)~bitmap_bits[uip_reasslen / 8 & 7]) { - goto nullreturn; - } - - /* If we have come this far, we have a full packet in the - buffer, so we allocate a pbuf and copy the packet into it. We - also reset the timer. */ - uip_reasstmr = 0; - memcpy(BUF, FBUF, uip_reasslen); - - /* Pretend to be a "normal" (i.e., not fragmented) IP packet - from now on. */ - BUF->ipoffset[0] = BUF->ipoffset[1] = 0; - BUF->len[0] = uip_reasslen >> 8; - BUF->len[1] = uip_reasslen & 0xff; - BUF->ipchksum = 0; - BUF->ipchksum = ~(uip_ipchksum()); - - return uip_reasslen; - } - } - - nullreturn: - return 0; -} -#endif /* UIP_REASSEMBLY */ -/*---------------------------------------------------------------------------*/ -static void -uip_add_rcv_nxt(u16_t n) -{ - uip_add32(uip_conn->rcv_nxt, n); - uip_conn->rcv_nxt[0] = uip_acc32[0]; - uip_conn->rcv_nxt[1] = uip_acc32[1]; - uip_conn->rcv_nxt[2] = uip_acc32[2]; - uip_conn->rcv_nxt[3] = uip_acc32[3]; -} -/*---------------------------------------------------------------------------*/ -void -uip_process(u8_t flag) -{ - register struct uip_conn *uip_connr = uip_conn; - -#if UIP_UDP - if(flag == UIP_UDP_SEND_CONN) { - goto udp_send; - } -#endif /* UIP_UDP */ - - uip_sappdata = uip_appdata = &uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN]; - - /* Check if we were invoked because of a poll request for a - particular connection. */ - if(flag == UIP_POLL_REQUEST) { - if((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED && - !uip_outstanding(uip_connr)) { - uip_len = uip_slen = 0; - uip_flags = UIP_POLL; - UIP_APPCALL(); - goto appsend; - } - goto drop; - - /* Check if we were invoked because of the periodic timer firing. */ - } else if(flag == UIP_TIMER) { -#if UIP_REASSEMBLY - if(uip_reasstmr != 0) { - --uip_reasstmr; - } -#endif /* UIP_REASSEMBLY */ - /* Increase the initial sequence number. */ - if(++iss[3] == 0) { - if(++iss[2] == 0) { - if(++iss[1] == 0) { - ++iss[0]; - } - } - } - - /* Reset the length variables. */ - uip_len = 0; - uip_slen = 0; - - /* Check if the connection is in a state in which we simply wait - for the connection to time out. If so, we increase the - connection's timer and remove the connection if it times - out. */ - if(uip_connr->tcpstateflags == UIP_TIME_WAIT || - uip_connr->tcpstateflags == UIP_FIN_WAIT_2) { - ++(uip_connr->timer); - if(uip_connr->timer == UIP_TIME_WAIT_TIMEOUT) { - uip_connr->tcpstateflags = UIP_CLOSED; - } - } else if(uip_connr->tcpstateflags != UIP_CLOSED) { - /* If the connection has outstanding data, we increase the - connection's timer and see if it has reached the RTO value - in which case we retransmit. */ - if(uip_outstanding(uip_connr)) { - if(uip_connr->timer-- == 0) { - if(uip_connr->nrtx == UIP_MAXRTX || - ((uip_connr->tcpstateflags == UIP_SYN_SENT || - uip_connr->tcpstateflags == UIP_SYN_RCVD) && - uip_connr->nrtx == UIP_MAXSYNRTX)) { - uip_connr->tcpstateflags = UIP_CLOSED; - - /* We call UIP_APPCALL() with uip_flags set to - UIP_TIMEDOUT to inform the application that the - connection has timed out. */ - uip_flags = UIP_TIMEDOUT; - UIP_APPCALL(); - - /* We also send a reset packet to the remote host. */ - BUF->flags = TCP_RST | TCP_ACK; - goto tcp_send_nodata; - } - - /* Exponential back-off. */ - uip_connr->timer = UIP_RTO << (uip_connr->nrtx > 4? - 4: - uip_connr->nrtx); - ++(uip_connr->nrtx); - - /* Ok, so we need to retransmit. We do this differently - depending on which state we are in. In ESTABLISHED, we - call upon the application so that it may prepare the - data for the retransmit. In SYN_RCVD, we resend the - SYNACK that we sent earlier and in LAST_ACK we have to - retransmit our FINACK. */ - UIP_STAT(++uip_stat.tcp.rexmit); - switch(uip_connr->tcpstateflags & UIP_TS_MASK) { - case UIP_SYN_RCVD: - /* In the SYN_RCVD state, we should retransmit our - SYNACK. */ - goto tcp_send_synack; - -#if UIP_ACTIVE_OPEN - case UIP_SYN_SENT: - /* In the SYN_SENT state, we retransmit out SYN. */ - BUF->flags = 0; - goto tcp_send_syn; -#endif /* UIP_ACTIVE_OPEN */ - - case UIP_ESTABLISHED: - /* In the ESTABLISHED state, we call upon the application - to do the actual retransmit after which we jump into - the code for sending out the packet (the apprexmit - label). */ - uip_flags = UIP_REXMIT; - UIP_APPCALL(); - goto apprexmit; - - case UIP_FIN_WAIT_1: - case UIP_CLOSING: - case UIP_LAST_ACK: - /* In all these states we should retransmit a FINACK. */ - goto tcp_send_finack; - - } - } - } else if((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED) { - /* If there was no need for a retransmission, we poll the - application for new data. */ - uip_len = uip_slen = 0; - uip_flags = UIP_POLL; - UIP_APPCALL(); - goto appsend; - } - } - goto drop; - } -#if UIP_UDP - if(flag == UIP_UDP_TIMER) { - if(uip_udp_conn->lport != 0) { - uip_conn = NULL; - uip_sappdata = uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN]; - uip_len = uip_slen = 0; - uip_flags = UIP_POLL; - UIP_UDP_APPCALL(); - goto udp_send; - } else { - goto drop; - } - } -#endif - - /* This is where the input processing starts. */ - UIP_STAT(++uip_stat.ip.recv); - - /* Start of IP input header processing code. */ - -#if UIP_CONF_IPV6 - /* Check validity of the IP header. */ - if((BUF->vtc & 0xf0) != 0x60) { /* IP version and header length. */ - UIP_STAT(++uip_stat.ip.drop); - UIP_STAT(++uip_stat.ip.vhlerr); - UIP_LOG("ipv6: invalid version."); - goto drop; - } -#else /* UIP_CONF_IPV6 */ - /* Check validity of the IP header. */ - if(BUF->vhl != 0x45) { /* IP version and header length. */ - UIP_STAT(++uip_stat.ip.drop); - UIP_STAT(++uip_stat.ip.vhlerr); - UIP_LOG("ip: invalid version or header length."); - goto drop; - } -#endif /* UIP_CONF_IPV6 */ - - /* Check the size of the packet. If the size reported to us in - uip_len is smaller the size reported in the IP header, we assume - that the packet has been corrupted in transit. If the size of - uip_len is larger than the size reported in the IP packet header, - the packet has been padded and we set uip_len to the correct - value.. */ - - if((BUF->len[0] << 8) + BUF->len[1] <= uip_len) { - uip_len = (BUF->len[0] << 8) + BUF->len[1]; -#if UIP_CONF_IPV6 - uip_len += 40; /* The length reported in the IPv6 header is the - length of the payload that follows the - header. However, uIP uses the uip_len variable - for holding the size of the entire packet, - including the IP header. For IPv4 this is not a - problem as the length field in the IPv4 header - contains the length of the entire packet. But - for IPv6 we need to add the size of the IPv6 - header (40 bytes). */ -#endif /* UIP_CONF_IPV6 */ - } else { - UIP_LOG("ip: packet shorter than reported in IP header."); - goto drop; - } - -#if !UIP_CONF_IPV6 - /* Check the fragment flag. */ - if((BUF->ipoffset[0] & 0x3f) != 0 || - BUF->ipoffset[1] != 0) { -#if UIP_REASSEMBLY - uip_len = uip_reass(); - if(uip_len == 0) { - goto drop; - } -#else /* UIP_REASSEMBLY */ - UIP_STAT(++uip_stat.ip.drop); - UIP_STAT(++uip_stat.ip.fragerr); - UIP_LOG("ip: fragment dropped."); - goto drop; -#endif /* UIP_REASSEMBLY */ - } -#endif /* UIP_CONF_IPV6 */ - - if(uip_ipaddr_cmp(&uip_hostaddr, &uip_all_zeroes_addr)) { - /* If we are configured to use ping IP address configuration and - hasn't been assigned an IP address yet, we accept all ICMP - packets. */ -#if UIP_PINGADDRCONF && !UIP_CONF_IPV6 - if(BUF->proto == UIP_PROTO_ICMP) { - UIP_LOG("ip: possible ping config packet received."); - goto icmp_input; - } else { - UIP_LOG("ip: packet dropped since no address assigned."); - goto drop; - } -#endif /* UIP_PINGADDRCONF */ - - } else { - /* If IP broadcast support is configured, we check for a broadcast - UDP packet, which may be destined to us. */ -#if UIP_BROADCAST - DEBUG_PRINTF("UDP IP checksum 0x%04x\n", uip_ipchksum()); - if(BUF->proto == UIP_PROTO_UDP && - uip_ipaddr_cmp(&BUF->destipaddr, &uip_broadcast_addr)) - { - if (uip_ipaddr_cmp(&BUF->srcipaddr, &uip_all_zeroes_addr)) - uip_ipaddr_copy(&BUF->srcipaddr, &uip_broadcast_addr); - - goto udp_input; - } -#endif /* UIP_BROADCAST */ - - /* Check if the packet is destined for our IP address. */ -#if !UIP_CONF_IPV6 - if(!uip_ipaddr_cmp(&BUF->destipaddr, &uip_hostaddr)) { - UIP_STAT(++uip_stat.ip.drop); - goto drop; - } -#else /* UIP_CONF_IPV6 */ - /* For IPv6, packet reception is a little trickier as we need to - make sure that we listen to certain multicast addresses (all - hosts multicast address, and the solicited-node multicast - address) as well. However, we will cheat here and accept all - multicast packets that are sent to the ff02::/16 addresses. */ - if(!uip_ipaddr_cmp(&BUF->destipaddr, &uip_hostaddr) && - BUF->destipaddr.u16[0] != HTONS(0xff02)) { - UIP_STAT(++uip_stat.ip.drop); - goto drop; - } -#endif /* UIP_CONF_IPV6 */ - } - -#if !UIP_CONF_IPV6 - if(uip_ipchksum() != 0xffff) { /* Compute and check the IP header - checksum. */ - UIP_STAT(++uip_stat.ip.drop); - UIP_STAT(++uip_stat.ip.chkerr); - UIP_LOG("ip: bad checksum."); - goto drop; - } -#endif /* UIP_CONF_IPV6 */ - - if(BUF->proto == UIP_PROTO_TCP) { /* Check for TCP packet. If so, - proceed with TCP input - processing. */ - goto tcp_input; - } - -#if UIP_UDP - if(BUF->proto == UIP_PROTO_UDP) { - goto udp_input; - } -#endif /* UIP_UDP */ - -#if !UIP_CONF_IPV6 - /* ICMPv4 processing code follows. */ - if(BUF->proto != UIP_PROTO_ICMP) { /* We only allow ICMP packets from - here. */ - UIP_STAT(++uip_stat.ip.drop); - UIP_STAT(++uip_stat.ip.protoerr); - UIP_LOG("ip: neither tcp nor icmp."); - goto drop; - } - -#if UIP_PINGADDRCONF - icmp_input: -#endif /* UIP_PINGADDRCONF */ - UIP_STAT(++uip_stat.icmp.recv); - - /* ICMP echo (i.e., ping) processing. This is simple, we only change - the ICMP type from ECHO to ECHO_REPLY and adjust the ICMP - checksum before we return the packet. */ - if(ICMPBUF->type != ICMP_ECHO) { - UIP_STAT(++uip_stat.icmp.drop); - UIP_STAT(++uip_stat.icmp.typeerr); - UIP_LOG("icmp: not icmp echo."); - goto drop; - } - - /* If we are configured to use ping IP address assignment, we use - the destination IP address of this ping packet and assign it to - yourself. */ -#if UIP_PINGADDRCONF - if(uip_ipaddr_cmp(&uip_hostaddr, &uip_all_zeroes_addr)) { - uip_hostaddr = BUF->destipaddr; - } -#endif /* UIP_PINGADDRCONF */ - - ICMPBUF->type = ICMP_ECHO_REPLY; - - if(ICMPBUF->icmpchksum >= HTONS(0xffff - (ICMP_ECHO << 8))) { - ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8) + 1; - } else { - ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8); - } - - /* Swap IP addresses. */ - uip_ipaddr_copy(&BUF->destipaddr, &BUF->srcipaddr); - uip_ipaddr_copy(&BUF->srcipaddr, &uip_hostaddr); - - UIP_STAT(++uip_stat.icmp.sent); - BUF->ttl = UIP_TTL; - goto ip_send_nolen; - - /* End of IPv4 input header processing code. */ -#else /* !UIP_CONF_IPV6 */ - - /* This is IPv6 ICMPv6 processing code. */ - DEBUG_PRINTF("icmp6_input: length %d\n", uip_len); - - if(BUF->proto != UIP_PROTO_ICMP6) { /* We only allow ICMPv6 packets from - here. */ - UIP_STAT(++uip_stat.ip.drop); - UIP_STAT(++uip_stat.ip.protoerr); - UIP_LOG("ip: neither tcp nor icmp6."); - goto drop; - } - - UIP_STAT(++uip_stat.icmp.recv); - - /* If we get a neighbor solicitation for our address we should send - a neighbor advertisement message back. */ - if(ICMPBUF->type == ICMP6_NEIGHBOR_SOLICITATION) { - if(uip_ipaddr_cmp(&ICMPBUF->icmp6data, &uip_hostaddr)) { - - if(ICMPBUF->options[0] == ICMP6_OPTION_SOURCE_LINK_ADDRESS) { - /* Save the sender's address in our neighbor list. */ - uip_neighbor_add(&ICMPBUF->srcipaddr, &(ICMPBUF->options[2])); - } - - /* We should now send a neighbor advertisement back to where the - neighbor solicitation came from. */ - ICMPBUF->type = ICMP6_NEIGHBOR_ADVERTISEMENT; - ICMPBUF->flags = ICMP6_FLAG_S; /* Solicited flag. */ - - ICMPBUF->reserved1 = ICMPBUF->reserved2 = ICMPBUF->reserved3 = 0; - - uip_ipaddr_copy(&ICMPBUF->destipaddr, &ICMPBUF->srcipaddr); - uip_ipaddr_copy(&ICMPBUF->srcipaddr, &uip_hostaddr); - ICMPBUF->options[0] = ICMP6_OPTION_TARGET_LINK_ADDRESS; - ICMPBUF->options[1] = 1; /* Options length, 1 = 8 bytes. */ - memcpy(&(ICMPBUF->options[2]), &uip_ethaddr, sizeof(uip_ethaddr)); - ICMPBUF->icmpchksum = 0; - ICMPBUF->icmpchksum = ~uip_icmp6chksum(); - - goto send; - - } - goto drop; - } else if(ICMPBUF->type == ICMP6_ECHO) { - /* ICMP echo (i.e., ping) processing. This is simple, we only - change the ICMP type from ECHO to ECHO_REPLY and update the - ICMP checksum before we return the packet. */ - - ICMPBUF->type = ICMP6_ECHO_REPLY; - - uip_ipaddr_copy(&BUF->destipaddr, &BUF->srcipaddr); - uip_ipaddr_copy(&BUF->srcipaddr, &uip_hostaddr); - ICMPBUF->icmpchksum = 0; - ICMPBUF->icmpchksum = ~uip_icmp6chksum(); - - UIP_STAT(++uip_stat.icmp.sent); - goto send; - } else { - DEBUG_PRINTF("Unknown icmp6 message type %d\n", ICMPBUF->type); - UIP_STAT(++uip_stat.icmp.drop); - UIP_STAT(++uip_stat.icmp.typeerr); - UIP_LOG("icmp: unknown ICMP message."); - goto drop; - } - - /* End of IPv6 ICMP processing. */ - -#endif /* !UIP_CONF_IPV6 */ - -#if UIP_UDP - /* UDP input processing. */ - udp_input: - /* UDP processing is really just a hack. We don't do anything to the - UDP/IP headers, but let the UDP application do all the hard - work. If the application sets uip_slen, it has a packet to - send. */ -#if UIP_UDP_CHECKSUMS - uip_len = uip_len - UIP_IPUDPH_LEN; - uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN]; - if(UDPBUF->udpchksum != 0 && uip_udpchksum() != 0xffff) { - UIP_STAT(++uip_stat.udp.drop); - UIP_STAT(++uip_stat.udp.chkerr); - UIP_LOG("udp: bad checksum."); - goto drop; - } -#else /* UIP_UDP_CHECKSUMS */ - uip_len = uip_len - UIP_IPUDPH_LEN; -#endif /* UIP_UDP_CHECKSUMS */ - - /* Demultiplex this UDP packet between the UDP "connections". */ - for(uip_udp_conn = &uip_udp_conns[0]; - uip_udp_conn < &uip_udp_conns[UIP_UDP_CONNS]; - ++uip_udp_conn) { - /* If the local UDP port is non-zero, the connection is considered - to be used. If so, the local port number is checked against the - destination port number in the received packet. If the two port - numbers match, the remote port number is checked if the - connection is bound to a remote port. Finally, if the - connection is bound to a remote IP address, the source IP - address of the packet is checked. */ - if(uip_udp_conn->lport != 0 && - UDPBUF->destport == uip_udp_conn->lport && - (uip_udp_conn->rport == 0 || - UDPBUF->srcport == uip_udp_conn->rport) && - (uip_ipaddr_cmp(&uip_udp_conn->ripaddr, &uip_all_zeroes_addr) || - uip_ipaddr_cmp(&uip_udp_conn->ripaddr, &uip_broadcast_addr) || - uip_ipaddr_cmp(&BUF->srcipaddr, &uip_udp_conn->ripaddr))) { - goto udp_found; - } - } - UIP_LOG("udp: no matching connection found"); -#if UIP_CONF_ICMP_DEST_UNREACH && !UIP_CONF_IPV6 - /* Copy fields from packet header into payload of this ICMP packet. */ - memcpy(&(ICMPBUF->payload[0]), ICMPBUF, UIP_IPH_LEN + 8); - - /* Set the ICMP type and code. */ - ICMPBUF->type = ICMP_DEST_UNREACHABLE; - ICMPBUF->icode = ICMP_PORT_UNREACHABLE; - - /* Calculate the ICMP checksum. */ - ICMPBUF->icmpchksum = 0; - ICMPBUF->icmpchksum = ~uip_chksum((u16_t *)&(ICMPBUF->type), 36); - - /* Set the IP destination address to be the source address of the - original packet. */ - uip_ipaddr_copy(&BUF->destipaddr, &BUF->srcipaddr); - - /* Set our IP address as the source address. */ - uip_ipaddr_copy(&BUF->srcipaddr, &uip_hostaddr); - - /* The size of the ICMP destination unreachable packet is 36 + the - size of the IP header (20) = 56. */ - uip_len = 36 + UIP_IPH_LEN; - ICMPBUF->len[0] = 0; - ICMPBUF->len[1] = (u8_t)uip_len; - ICMPBUF->ttl = UIP_TTL; - ICMPBUF->proto = UIP_PROTO_ICMP; - - goto ip_send_nolen; -#else /* UIP_CONF_ICMP_DEST_UNREACH */ - goto drop; -#endif /* UIP_CONF_ICMP_DEST_UNREACH */ - - udp_found: - uip_conn = NULL; - uip_flags = UIP_NEWDATA; - uip_sappdata = uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN]; - uip_slen = 0; - UIP_UDP_APPCALL(); - - udp_send: - if(uip_slen == 0) { - goto drop; - } - uip_len = uip_slen + UIP_IPUDPH_LEN; - -#if UIP_CONF_IPV6 - /* For IPv6, the IP length field does not include the IPv6 IP header - length. */ - BUF->len[0] = ((uip_len - UIP_IPH_LEN) >> 8); - BUF->len[1] = ((uip_len - UIP_IPH_LEN) & 0xff); -#else /* UIP_CONF_IPV6 */ - BUF->len[0] = (uip_len >> 8); - BUF->len[1] = (uip_len & 0xff); -#endif /* UIP_CONF_IPV6 */ - - BUF->ttl = uip_udp_conn->ttl; - BUF->proto = UIP_PROTO_UDP; - - UDPBUF->udplen = HTONS(uip_slen + UIP_UDPH_LEN); - UDPBUF->udpchksum = 0; - - BUF->srcport = uip_udp_conn->lport; - BUF->destport = uip_udp_conn->rport; - - uip_ipaddr_copy(&BUF->srcipaddr, &uip_hostaddr); - uip_ipaddr_copy(&BUF->destipaddr, &uip_udp_conn->ripaddr); - - uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPTCPH_LEN]; - -#if UIP_UDP_CHECKSUMS - /* Calculate UDP checksum. */ - UDPBUF->udpchksum = ~(uip_udpchksum()); - if(UDPBUF->udpchksum == 0) { - UDPBUF->udpchksum = 0xffff; - } -#endif /* UIP_UDP_CHECKSUMS */ - - goto ip_send_nolen; -#endif /* UIP_UDP */ - - /* TCP input processing. */ - tcp_input: - UIP_STAT(++uip_stat.tcp.recv); - - /* Start of TCP input header processing code. */ - - if(uip_tcpchksum() != 0xffff) { /* Compute and check the TCP - checksum. */ - UIP_STAT(++uip_stat.tcp.drop); - UIP_STAT(++uip_stat.tcp.chkerr); - UIP_LOG("tcp: bad checksum."); - goto drop; - } - - /* Demultiplex this segment. */ - /* First check any active connections. */ - for(uip_connr = &uip_conns[0]; uip_connr <= &uip_conns[UIP_CONNS - 1]; - ++uip_connr) { - if(uip_connr->tcpstateflags != UIP_CLOSED && - BUF->destport == uip_connr->lport && - BUF->srcport == uip_connr->rport && - uip_ipaddr_cmp(&BUF->srcipaddr, &uip_connr->ripaddr)) { - goto found; - } - } - - /* If we didn't find and active connection that expected the packet, - either this packet is an old duplicate, or this is a SYN packet - destined for a connection in LISTEN. If the SYN flag isn't set, - it is an old packet and we send a RST. */ - if((BUF->flags & TCP_CTL) != TCP_SYN) { - goto reset; - } - - tmp16 = BUF->destport; - /* Next, check listening connections. */ - for(c = 0; c < UIP_LISTENPORTS; ++c) { - if(tmp16 == uip_listenports[c]) { - goto found_listen; - } - } - - /* No matching connection found, so we send a RST packet. */ - UIP_STAT(++uip_stat.tcp.synrst); - - reset: - /* We do not send resets in response to resets. */ - if(BUF->flags & TCP_RST) { - goto drop; - } - - UIP_STAT(++uip_stat.tcp.rst); - - BUF->flags = TCP_RST | TCP_ACK; - uip_len = UIP_IPTCPH_LEN; - BUF->tcpoffset = 5 << 4; - - /* Flip the seqno and ackno fields in the TCP header. */ - c = BUF->seqno[3]; - BUF->seqno[3] = BUF->ackno[3]; - BUF->ackno[3] = c; - - c = BUF->seqno[2]; - BUF->seqno[2] = BUF->ackno[2]; - BUF->ackno[2] = c; - - c = BUF->seqno[1]; - BUF->seqno[1] = BUF->ackno[1]; - BUF->ackno[1] = c; - - c = BUF->seqno[0]; - BUF->seqno[0] = BUF->ackno[0]; - BUF->ackno[0] = c; - - /* We also have to increase the sequence number we are - acknowledging. If the least significant byte overflowed, we need - to propagate the carry to the other bytes as well. */ - if(++BUF->ackno[3] == 0) { - if(++BUF->ackno[2] == 0) { - if(++BUF->ackno[1] == 0) { - ++BUF->ackno[0]; - } - } - } - - /* Swap port numbers. */ - tmp16 = BUF->srcport; - BUF->srcport = BUF->destport; - BUF->destport = tmp16; - - /* Swap IP addresses. */ - uip_ipaddr_copy(&BUF->destipaddr, &BUF->srcipaddr); - uip_ipaddr_copy(&BUF->srcipaddr, &uip_hostaddr); - - /* And send out the RST packet! */ - goto tcp_send_noconn; - - /* This label will be jumped to if we matched the incoming packet - with a connection in LISTEN. In that case, we should create a new - connection and send a SYNACK in return. */ - found_listen: - /* First we check if there are any connections available. Unused - connections are kept in the same table as used connections, but - unused ones have the tcpstate set to CLOSED. Also, connections in - TIME_WAIT are kept track of and we'll use the oldest one if no - CLOSED connections are found. Thanks to Eddie C. Dost for a very - nice algorithm for the TIME_WAIT search. */ - uip_connr = 0; - for(c = 0; c < UIP_CONNS; ++c) { - if(uip_conns[c].tcpstateflags == UIP_CLOSED) { - uip_connr = &uip_conns[c]; - break; - } - if(uip_conns[c].tcpstateflags == UIP_TIME_WAIT) { - if(uip_connr == 0 || - uip_conns[c].timer > uip_connr->timer) { - uip_connr = &uip_conns[c]; - } - } - } - - if(uip_connr == 0) { - /* All connections are used already, we drop packet and hope that - the remote end will retransmit the packet at a time when we - have more spare connections. */ - UIP_STAT(++uip_stat.tcp.syndrop); - UIP_LOG("tcp: found no unused connections."); - goto drop; - } - uip_conn = uip_connr; - - /* Fill in the necessary fields for the new connection. */ - uip_connr->rto = uip_connr->timer = UIP_RTO; - uip_connr->sa = 0; - uip_connr->sv = 4; - uip_connr->nrtx = 0; - uip_connr->lport = BUF->destport; - uip_connr->rport = BUF->srcport; - uip_ipaddr_copy(&uip_connr->ripaddr, &BUF->srcipaddr); - uip_connr->tcpstateflags = UIP_SYN_RCVD; - - uip_connr->snd_nxt[0] = iss[0]; - uip_connr->snd_nxt[1] = iss[1]; - uip_connr->snd_nxt[2] = iss[2]; - uip_connr->snd_nxt[3] = iss[3]; - uip_connr->len = 1; - - /* rcv_nxt should be the seqno from the incoming packet + 1. */ - uip_connr->rcv_nxt[3] = BUF->seqno[3]; - uip_connr->rcv_nxt[2] = BUF->seqno[2]; - uip_connr->rcv_nxt[1] = BUF->seqno[1]; - uip_connr->rcv_nxt[0] = BUF->seqno[0]; - uip_add_rcv_nxt(1); - - /* Parse the TCP MSS option, if present. */ - if((BUF->tcpoffset & 0xf0) > 0x50) { - for(c = 0; c < ((BUF->tcpoffset >> 4) - 5) << 2 ;) { - opt = uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + c]; - if(opt == TCP_OPT_END) { - /* End of options. */ - break; - } else if(opt == TCP_OPT_NOOP) { - ++c; - /* NOP option. */ - } else if(opt == TCP_OPT_MSS && - uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == TCP_OPT_MSS_LEN) { - /* An MSS option with the right option length. */ - tmp16 = ((u16_t)uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + c] << 8) | - (u16_t)uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN + 3 + c]; - uip_connr->initialmss = uip_connr->mss = - tmp16 > UIP_TCP_MSS? UIP_TCP_MSS: tmp16; - - /* And we are done processing options. */ - break; - } else { - /* All other options have a length field, so that we easily - can skip past them. */ - if(uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == 0) { - /* If the length field is zero, the options are malformed - and we don't process them further. */ - break; - } - c += uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c]; - } - } - } - - /* Our response will be a SYNACK. */ -#if UIP_ACTIVE_OPEN - tcp_send_synack: - BUF->flags = TCP_ACK; - - tcp_send_syn: - BUF->flags |= TCP_SYN; -#else /* UIP_ACTIVE_OPEN */ - tcp_send_synack: - BUF->flags = TCP_SYN | TCP_ACK; -#endif /* UIP_ACTIVE_OPEN */ - - /* We send out the TCP Maximum Segment Size option with our - SYNACK. */ - BUF->optdata[0] = TCP_OPT_MSS; - BUF->optdata[1] = TCP_OPT_MSS_LEN; - BUF->optdata[2] = (UIP_TCP_MSS) / 256; - BUF->optdata[3] = (UIP_TCP_MSS) & 255; - uip_len = UIP_IPTCPH_LEN + TCP_OPT_MSS_LEN; - BUF->tcpoffset = ((UIP_TCPH_LEN + TCP_OPT_MSS_LEN) / 4) << 4; - goto tcp_send; - - /* This label will be jumped to if we found an active connection. */ - found: - uip_conn = uip_connr; - uip_flags = 0; - /* We do a very naive form of TCP reset processing; we just accept - any RST and kill our connection. We should in fact check if the - sequence number of this reset is within our advertised window - before we accept the reset. */ - if(BUF->flags & TCP_RST) { - uip_connr->tcpstateflags = UIP_CLOSED; - UIP_LOG("tcp: got reset, aborting connection."); - uip_flags = UIP_ABORT; - UIP_APPCALL(); - goto drop; - } - /* Calculate the length of the data, if the application has sent - any data to us. */ - c = (BUF->tcpoffset >> 4) << 2; - /* uip_len will contain the length of the actual TCP data. This is - calculated by subtracing the length of the TCP header (in - c) and the length of the IP header (20 bytes). */ - uip_len = uip_len - c - UIP_IPH_LEN; - - /* First, check if the sequence number of the incoming packet is - what we're expecting next. If not, we send out an ACK with the - correct numbers in. */ - if(!(((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_SYN_SENT) && - ((BUF->flags & TCP_CTL) == (TCP_SYN | TCP_ACK)))) { - if((uip_len > 0 || ((BUF->flags & (TCP_SYN | TCP_FIN)) != 0)) && - (BUF->seqno[0] != uip_connr->rcv_nxt[0] || - BUF->seqno[1] != uip_connr->rcv_nxt[1] || - BUF->seqno[2] != uip_connr->rcv_nxt[2] || - BUF->seqno[3] != uip_connr->rcv_nxt[3])) { - goto tcp_send_ack; - } - } - - /* Next, check if the incoming segment acknowledges any outstanding - data. If so, we update the sequence number, reset the length of - the outstanding data, calculate RTT estimations, and reset the - retransmission timer. */ - if((BUF->flags & TCP_ACK) && uip_outstanding(uip_connr)) { - uip_add32(uip_connr->snd_nxt, uip_connr->len); - - if(BUF->ackno[0] == uip_acc32[0] && - BUF->ackno[1] == uip_acc32[1] && - BUF->ackno[2] == uip_acc32[2] && - BUF->ackno[3] == uip_acc32[3]) { - /* Update sequence number. */ - uip_connr->snd_nxt[0] = uip_acc32[0]; - uip_connr->snd_nxt[1] = uip_acc32[1]; - uip_connr->snd_nxt[2] = uip_acc32[2]; - uip_connr->snd_nxt[3] = uip_acc32[3]; - - /* Do RTT estimation, unless we have done retransmissions. */ - if(uip_connr->nrtx == 0) { - signed char m; - m = uip_connr->rto - uip_connr->timer; - /* This is taken directly from VJs original code in his paper */ - m = m - (uip_connr->sa >> 3); - uip_connr->sa += m; - if(m < 0) { - m = -m; - } - m = m - (uip_connr->sv >> 2); - uip_connr->sv += m; - uip_connr->rto = (uip_connr->sa >> 3) + uip_connr->sv; - - } - /* Set the acknowledged flag. */ - uip_flags = UIP_ACKDATA; - /* Reset the retransmission timer. */ - uip_connr->timer = uip_connr->rto; - - /* Reset length of outstanding data. */ - uip_connr->len = 0; - } - - } - - /* Do different things depending on in what state the connection is. */ - switch(uip_connr->tcpstateflags & UIP_TS_MASK) { - /* CLOSED and LISTEN are not handled here. CLOSE_WAIT is not - implemented, since we force the application to close when the - peer sends a FIN (hence the application goes directly from - ESTABLISHED to LAST_ACK). */ - case UIP_SYN_RCVD: - /* In SYN_RCVD we have sent out a SYNACK in response to a SYN, and - we are waiting for an ACK that acknowledges the data we sent - out the last time. Therefore, we want to have the UIP_ACKDATA - flag set. If so, we enter the ESTABLISHED state. */ - if(uip_flags & UIP_ACKDATA) { - uip_connr->tcpstateflags = UIP_ESTABLISHED; - uip_flags = UIP_CONNECTED; - uip_connr->len = 0; - if(uip_len > 0) { - uip_flags |= UIP_NEWDATA; - uip_add_rcv_nxt(uip_len); - } - uip_slen = 0; - UIP_APPCALL(); - goto appsend; - } - goto drop; -#if UIP_ACTIVE_OPEN - case UIP_SYN_SENT: - /* In SYN_SENT, we wait for a SYNACK that is sent in response to - our SYN. The rcv_nxt is set to sequence number in the SYNACK - plus one, and we send an ACK. We move into the ESTABLISHED - state. */ - if((uip_flags & UIP_ACKDATA) && - (BUF->flags & TCP_CTL) == (TCP_SYN | TCP_ACK)) { - - /* Parse the TCP MSS option, if present. */ - if((BUF->tcpoffset & 0xf0) > 0x50) { - for(c = 0; c < ((BUF->tcpoffset >> 4) - 5) << 2 ;) { - opt = uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN + c]; - if(opt == TCP_OPT_END) { - /* End of options. */ - break; - } else if(opt == TCP_OPT_NOOP) { - ++c; - /* NOP option. */ - } else if(opt == TCP_OPT_MSS && - uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == TCP_OPT_MSS_LEN) { - /* An MSS option with the right option length. */ - tmp16 = (uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + c] << 8) | - uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 3 + c]; - uip_connr->initialmss = - uip_connr->mss = tmp16 > UIP_TCP_MSS? UIP_TCP_MSS: tmp16; - - /* And we are done processing options. */ - break; - } else { - /* All other options have a length field, so that we easily - can skip past them. */ - if(uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == 0) { - /* If the length field is zero, the options are malformed - and we don't process them further. */ - break; - } - c += uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c]; - } - } - } - uip_connr->tcpstateflags = UIP_ESTABLISHED; - uip_connr->rcv_nxt[0] = BUF->seqno[0]; - uip_connr->rcv_nxt[1] = BUF->seqno[1]; - uip_connr->rcv_nxt[2] = BUF->seqno[2]; - uip_connr->rcv_nxt[3] = BUF->seqno[3]; - uip_add_rcv_nxt(1); - uip_flags = UIP_CONNECTED | UIP_NEWDATA; - uip_connr->len = 0; - uip_len = 0; - uip_slen = 0; - UIP_APPCALL(); - goto appsend; - } - /* Inform the application that the connection failed */ - uip_flags = UIP_ABORT; - UIP_APPCALL(); - /* The connection is closed after we send the RST */ - uip_conn->tcpstateflags = UIP_CLOSED; - goto reset; -#endif /* UIP_ACTIVE_OPEN */ - - case UIP_ESTABLISHED: - /* In the ESTABLISHED state, we call upon the application to feed - data into the uip_buf. If the UIP_ACKDATA flag is set, the - application should put new data into the buffer, otherwise we are - retransmitting an old segment, and the application should put that - data into the buffer. - - If the incoming packet is a FIN, we should close the connection on - this side as well, and we send out a FIN and enter the LAST_ACK - state. We require that there is no outstanding data; otherwise the - sequence numbers will be screwed up. */ - - if(BUF->flags & TCP_FIN && !(uip_connr->tcpstateflags & UIP_STOPPED)) { - if(uip_outstanding(uip_connr)) { - goto drop; - } - uip_add_rcv_nxt(1 + uip_len); - uip_flags |= UIP_CLOSE; - if(uip_len > 0) { - uip_flags |= UIP_NEWDATA; - } - UIP_APPCALL(); - uip_connr->len = 1; - uip_connr->tcpstateflags = UIP_LAST_ACK; - uip_connr->nrtx = 0; - tcp_send_finack: - BUF->flags = TCP_FIN | TCP_ACK; - goto tcp_send_nodata; - } - - /* Check the URG flag. If this is set, the segment carries urgent - data that we must pass to the application. */ - if((BUF->flags & TCP_URG) != 0) { -#if UIP_URGDATA > 0 - uip_urglen = (BUF->urgp[0] << 8) | BUF->urgp[1]; - if(uip_urglen > uip_len) { - /* There is more urgent data in the next segment to come. */ - uip_urglen = uip_len; - } - uip_add_rcv_nxt(uip_urglen); - uip_len -= uip_urglen; - uip_urgdata = uip_appdata; - uip_appdata += uip_urglen; - } else { - uip_urglen = 0; -#else /* UIP_URGDATA > 0 */ - uip_appdata = ((char *)uip_appdata) + ((BUF->urgp[0] << 8) | BUF->urgp[1]); - uip_len -= (BUF->urgp[0] << 8) | BUF->urgp[1]; -#endif /* UIP_URGDATA > 0 */ - } - - /* If uip_len > 0 we have TCP data in the packet, and we flag this - by setting the UIP_NEWDATA flag and update the sequence number - we acknowledge. If the application has stopped the dataflow - using uip_stop(), we must not accept any data packets from the - remote host. */ - if(uip_len > 0 && !(uip_connr->tcpstateflags & UIP_STOPPED)) { - uip_flags |= UIP_NEWDATA; - uip_add_rcv_nxt(uip_len); - } - - /* Check if the available buffer space advertised by the other end - is smaller than the initial MSS for this connection. If so, we - set the current MSS to the window size to ensure that the - application does not send more data than the other end can - handle. - - If the remote host advertises a zero window, we set the MSS to - the initial MSS so that the application will send an entire MSS - of data. This data will not be acknowledged by the receiver, - and the application will retransmit it. This is called the - "persistent timer" and uses the retransmission mechanism. - */ - tmp16 = ((u16_t)BUF->wnd[0] << 8) + (u16_t)BUF->wnd[1]; - if(tmp16 > uip_connr->initialmss || - tmp16 == 0) { - tmp16 = uip_connr->initialmss; - } - uip_connr->mss = tmp16; - - /* If this packet constitutes an ACK for outstanding data (flagged - by the UIP_ACKDATA flag, we should call the application since it - might want to send more data. If the incoming packet had data - from the peer (as flagged by the UIP_NEWDATA flag), the - application must also be notified. - - When the application is called, the global variable uip_len - contains the length of the incoming data. The application can - access the incoming data through the global pointer - uip_appdata, which usually points UIP_IPTCPH_LEN + UIP_LLH_LEN - bytes into the uip_buf array. - - If the application wishes to send any data, this data should be - put into the uip_appdata and the length of the data should be - put into uip_len. If the application don't have any data to - send, uip_len must be set to 0. */ - if(uip_flags & (UIP_NEWDATA | UIP_ACKDATA)) { - uip_slen = 0; - UIP_APPCALL(); - - appsend: - - if(uip_flags & UIP_ABORT) { - uip_slen = 0; - uip_connr->tcpstateflags = UIP_CLOSED; - BUF->flags = TCP_RST | TCP_ACK; - goto tcp_send_nodata; - } - - if(uip_flags & UIP_CLOSE) { - uip_slen = 0; - uip_connr->len = 1; - uip_connr->tcpstateflags = UIP_FIN_WAIT_1; - uip_connr->nrtx = 0; - BUF->flags = TCP_FIN | TCP_ACK; - goto tcp_send_nodata; - } - - /* If uip_slen > 0, the application has data to be sent. */ - if(uip_slen > 0) { - - /* If the connection has acknowledged data, the contents of - the ->len variable should be discarded. */ - if((uip_flags & UIP_ACKDATA) != 0) { - uip_connr->len = 0; - } - - /* If the ->len variable is non-zero the connection has - already data in transit and cannot send anymore right - now. */ - if(uip_connr->len == 0) { - - /* The application cannot send more than what is allowed by - the mss (the minumum of the MSS and the available - window). */ - if(uip_slen > uip_connr->mss) { - uip_slen = uip_connr->mss; - } - - /* Remember how much data we send out now so that we know - when everything has been acknowledged. */ - uip_connr->len = uip_slen; - } else { - - /* If the application already had unacknowledged data, we - make sure that the application does not send (i.e., - retransmit) out more than it previously sent out. */ - uip_slen = uip_connr->len; - } - } - uip_connr->nrtx = 0; - apprexmit: - uip_appdata = uip_sappdata; - - /* If the application has data to be sent, or if the incoming - packet had new data in it, we must send out a packet. */ - if(uip_slen > 0 && uip_connr->len > 0) { - /* Add the length of the IP and TCP headers. */ - uip_len = uip_connr->len + UIP_TCPIP_HLEN; - /* We always set the ACK flag in response packets. */ - BUF->flags = TCP_ACK | TCP_PSH; - /* Send the packet. */ - goto tcp_send_noopts; - } - /* If there is no data to send, just send out a pure ACK if - there is newdata. */ - if(uip_flags & UIP_NEWDATA) { - uip_len = UIP_TCPIP_HLEN; - BUF->flags = TCP_ACK; - goto tcp_send_noopts; - } - } - goto drop; - case UIP_LAST_ACK: - /* We can close this connection if the peer has acknowledged our - FIN. This is indicated by the UIP_ACKDATA flag. */ - if(uip_flags & UIP_ACKDATA) { - uip_connr->tcpstateflags = UIP_CLOSED; - uip_flags = UIP_CLOSE; - UIP_APPCALL(); - } - break; - - case UIP_FIN_WAIT_1: - /* The application has closed the connection, but the remote host - hasn't closed its end yet. Thus we do nothing but wait for a - FIN from the other side. */ - if(uip_len > 0) { - uip_add_rcv_nxt(uip_len); - } - if(BUF->flags & TCP_FIN) { - if(uip_flags & UIP_ACKDATA) { - uip_connr->tcpstateflags = UIP_TIME_WAIT; - uip_connr->timer = 0; - uip_connr->len = 0; - } else { - uip_connr->tcpstateflags = UIP_CLOSING; - } - uip_add_rcv_nxt(1); - uip_flags = UIP_CLOSE; - UIP_APPCALL(); - goto tcp_send_ack; - } else if(uip_flags & UIP_ACKDATA) { - uip_connr->tcpstateflags = UIP_FIN_WAIT_2; - uip_connr->len = 0; - goto drop; - } - if(uip_len > 0) { - goto tcp_send_ack; - } - goto drop; - - case UIP_FIN_WAIT_2: - if(uip_len > 0) { - uip_add_rcv_nxt(uip_len); - } - if(BUF->flags & TCP_FIN) { - uip_connr->tcpstateflags = UIP_TIME_WAIT; - uip_connr->timer = 0; - uip_add_rcv_nxt(1); - uip_flags = UIP_CLOSE; - UIP_APPCALL(); - goto tcp_send_ack; - } - if(uip_len > 0) { - goto tcp_send_ack; - } - goto drop; - - case UIP_TIME_WAIT: - goto tcp_send_ack; - - case UIP_CLOSING: - if(uip_flags & UIP_ACKDATA) { - uip_connr->tcpstateflags = UIP_TIME_WAIT; - uip_connr->timer = 0; - } - } - goto drop; - - /* We jump here when we are ready to send the packet, and just want - to set the appropriate TCP sequence numbers in the TCP header. */ - tcp_send_ack: - BUF->flags = TCP_ACK; - - tcp_send_nodata: - uip_len = UIP_IPTCPH_LEN; - - tcp_send_noopts: - BUF->tcpoffset = (UIP_TCPH_LEN / 4) << 4; - - /* We're done with the input processing. We are now ready to send a - reply. Our job is to fill in all the fields of the TCP and IP - headers before calculating the checksum and finally send the - packet. */ - tcp_send: - BUF->ackno[0] = uip_connr->rcv_nxt[0]; - BUF->ackno[1] = uip_connr->rcv_nxt[1]; - BUF->ackno[2] = uip_connr->rcv_nxt[2]; - BUF->ackno[3] = uip_connr->rcv_nxt[3]; - - BUF->seqno[0] = uip_connr->snd_nxt[0]; - BUF->seqno[1] = uip_connr->snd_nxt[1]; - BUF->seqno[2] = uip_connr->snd_nxt[2]; - BUF->seqno[3] = uip_connr->snd_nxt[3]; - - BUF->proto = UIP_PROTO_TCP; - - BUF->srcport = uip_connr->lport; - BUF->destport = uip_connr->rport; - - uip_ipaddr_copy(&BUF->srcipaddr, &uip_hostaddr); - uip_ipaddr_copy(&BUF->destipaddr, &uip_connr->ripaddr); - - if(uip_connr->tcpstateflags & UIP_STOPPED) { - /* If the connection has issued uip_stop(), we advertise a zero - window so that the remote host will stop sending data. */ - BUF->wnd[0] = BUF->wnd[1] = 0; - } else { - BUF->wnd[0] = ((UIP_RECEIVE_WINDOW) >> 8); - BUF->wnd[1] = ((UIP_RECEIVE_WINDOW) & 0xff); - } - - tcp_send_noconn: - BUF->ttl = UIP_TTL; -#if UIP_CONF_IPV6 - /* For IPv6, the IP length field does not include the IPv6 IP header - length. */ - BUF->len[0] = ((uip_len - UIP_IPH_LEN) >> 8); - BUF->len[1] = ((uip_len - UIP_IPH_LEN) & 0xff); -#else /* UIP_CONF_IPV6 */ - BUF->len[0] = (uip_len >> 8); - BUF->len[1] = (uip_len & 0xff); -#endif /* UIP_CONF_IPV6 */ - - BUF->urgp[0] = BUF->urgp[1] = 0; - - /* Calculate TCP checksum. */ - BUF->tcpchksum = 0; - BUF->tcpchksum = ~(uip_tcpchksum()); - - ip_send_nolen: -#if UIP_CONF_IPV6 - BUF->vtc = 0x60; - BUF->tcflow = 0x00; - BUF->flow = 0x00; -#else /* UIP_CONF_IPV6 */ - BUF->vhl = 0x45; - BUF->tos = 0; - BUF->ipoffset[0] = BUF->ipoffset[1] = 0; - ++ipid; - BUF->ipid[0] = ipid >> 8; - BUF->ipid[1] = ipid & 0xff; - /* Calculate IP checksum. */ - BUF->ipchksum = 0; - BUF->ipchksum = ~(uip_ipchksum()); - DEBUG_PRINTF("uip ip_send_nolen: checksum 0x%04x\n", uip_ipchksum()); -#endif /* UIP_CONF_IPV6 */ - UIP_STAT(++uip_stat.tcp.sent); -#if UIP_CONF_IPV6 - send: -#endif /* UIP_CONF_IPV6 */ - DEBUG_PRINTF("Sending packet with length %d (%d)\n", uip_len, - (BUF->len[0] << 8) | BUF->len[1]); - - UIP_STAT(++uip_stat.ip.sent); - /* Return and let the caller do the actual transmission. */ - uip_flags = 0; - return; - - drop: - uip_len = 0; - uip_flags = 0; - return; -} -/*---------------------------------------------------------------------------*/ -u16_t -htons(u16_t val) -{ - return HTONS(val); -} - -u32_t -htonl(u32_t val) -{ - return HTONL(val); -} -/*---------------------------------------------------------------------------*/ -void -uip_send(const void *data, int len) -{ - int copylen; -#define MIN(a,b) ((a) < (b)? (a): (b)) - copylen = MIN(len, UIP_BUFSIZE - UIP_LLH_LEN - UIP_TCPIP_HLEN - - (int)((char *)uip_sappdata - (char *)&uip_buf[UIP_LLH_LEN + UIP_TCPIP_HLEN])); - if(copylen > 0) { - uip_slen = copylen; - if(data != uip_sappdata) { - memcpy(uip_sappdata, (data), uip_slen); - } - } -} -/*---------------------------------------------------------------------------*/ -/** @} */ -#endif /* UIP_CONF_IPV6 */ - |