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Danger-alarm/SOFTWARE-FreeRTOS/Common/ethernet/lwIP/netif/ppp/ppp.c

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2024-06-03 16:27:41 +08:00
/*****************************************************************************
* ppp.c - Network Point to Point Protocol program file.
*
* Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.
* portions Copyright (c) 1997 by Global Election Systems Inc.
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice and the following disclaimer are included verbatim in any
* distributions. No written agreement, license, or royalty fee is required
* for any of the authorized uses.
*
* THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
******************************************************************************
* REVISION HISTORY
*
* 03-01-01 Marc Boucher <marc@mbsi.ca>
* Ported to lwIP.
* 97-11-05 Guy Lancaster <lancasterg@acm.org>, Global Election Systems Inc.
* Original.
*****************************************************************************/
/*
* ppp_defs.h - PPP definitions.
*
* if_pppvar.h - private structures and declarations for PPP.
*
* Copyright (c) 1994 The Australian National University.
* All rights reserved.
*
* Permission to use, copy, modify, and distribute this software and its
* documentation is hereby granted, provided that the above copyright
* notice appears in all copies. This software is provided without any
* warranty, express or implied. The Australian National University
* makes no representations about the suitability of this software for
* any purpose.
*
* IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY
* PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
* THE AUSTRALIAN NATIONAL UNIVERSITY HAVE BEEN ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*
* THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO
* OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
* OR MODIFICATIONS.
*/
/*
* if_ppp.h - Point-to-Point Protocol definitions.
*
* Copyright (c) 1989 Carnegie Mellon University.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by Carnegie Mellon University. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#include <string.h>
#include "ppp.h"
#if PPP_SUPPORT > 0
#include "randm.h"
#include "fsm.h"
#if PAP_SUPPORT > 0
#include "pap.h"
#endif
#if CHAP_SUPPORT > 0
#include "chap.h"
#endif
#include "ipcp.h"
#include "lcp.h"
#include "magic.h"
#include "auth.h"
#if VJ_SUPPORT > 0
#include "vj.h"
#endif
#include "pppdebug.h"
/*************************/
/*** LOCAL DEFINITIONS ***/
/*************************/
/*
* The basic PPP frame.
*/
#define PPP_ADDRESS(p) (((u_char *)(p))[0])
#define PPP_CONTROL(p) (((u_char *)(p))[1])
#define PPP_PROTOCOL(p) ((((u_char *)(p))[2] << 8) + ((u_char *)(p))[3])
/* PPP packet parser states. Current state indicates operation yet to be
* completed. */
typedef enum {
PDIDLE = 0, /* Idle state - waiting. */
PDSTART, /* Process start flag. */
PDADDRESS, /* Process address field. */
PDCONTROL, /* Process control field. */
PDPROTOCOL1, /* Process protocol field 1. */
PDPROTOCOL2, /* Process protocol field 2. */
PDDATA /* Process data byte. */
} PPPDevStates;
#define ESCAPE_P(accm, c) ((accm)[(c) >> 3] & pppACCMMask[c & 0x07])
/************************/
/*** LOCAL DATA TYPES ***/
/************************/
/*
* PPP interface control block.
*/
typedef struct PPPControl_s {
char openFlag; /* True when in use. */
char oldFrame; /* Old framing character for fd. */
sio_fd_t fd; /* File device ID of port. */
int kill_link; /* Shut the link down. */
int sig_hup; /* Carrier lost. */
int if_up; /* True when the interface is up. */
int errCode; /* Code indicating why interface is down. */
struct pbuf *inHead, *inTail; /* The input packet. */
PPPDevStates inState; /* The input process state. */
char inEscaped; /* Escape next character. */
u16_t inProtocol; /* The input protocol code. */
u16_t inFCS; /* Input Frame Check Sequence value. */
int mtu; /* Peer's mru */
int pcomp; /* Does peer accept protocol compression? */
int accomp; /* Does peer accept addr/ctl compression? */
u_long lastXMit; /* Time of last transmission. */
ext_accm inACCM; /* Async-Ctl-Char-Map for input. */
ext_accm outACCM; /* Async-Ctl-Char-Map for output. */
#if VJ_SUPPORT > 0
int vjEnabled; /* Flag indicating VJ compression enabled. */
struct vjcompress vjComp; /* Van Jabobsen compression header. */
#endif
struct netif netif;
struct ppp_addrs addrs;
void (*linkStatusCB)(void *ctx, int errCode, void *arg);
void *linkStatusCtx;
} PPPControl;
/*
* Ioctl definitions.
*/
struct npioctl {
int protocol; /* PPP procotol, e.g. PPP_IP */
enum NPmode mode;
};
/***********************************/
/*** LOCAL FUNCTION DECLARATIONS ***/
/***********************************/
static void pppMain(void *pd);
static void pppDrop(PPPControl *pc);
static void pppInProc(int pd, u_char *s, int l);
/******************************/
/*** PUBLIC DATA STRUCTURES ***/
/******************************/
u_long subnetMask;
static PPPControl pppControl[NUM_PPP]; /* The PPP interface control blocks. */
/*
* PPP Data Link Layer "protocol" table.
* One entry per supported protocol.
* The last entry must be NULL.
*/
struct protent *ppp_protocols[] = {
&lcp_protent,
#if PAP_SUPPORT > 0
&pap_protent,
#endif
#if CHAP_SUPPORT > 0
&chap_protent,
#endif
#if CBCP_SUPPORT > 0
&cbcp_protent,
#endif
&ipcp_protent,
#if CCP_SUPPORT > 0
&ccp_protent,
#endif
NULL
};
/*
* Buffers for outgoing packets. This must be accessed only from the appropriate
* PPP task so that it doesn't need to be protected to avoid collisions.
*/
u_char outpacket_buf[NUM_PPP][PPP_MRU+PPP_HDRLEN];
/*****************************/
/*** LOCAL DATA STRUCTURES ***/
/*****************************/
/*
* FCS lookup table as calculated by genfcstab.
*/
static const u_short fcstab[256] = {
0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
};
/* PPP's Asynchronous-Control-Character-Map. The mask array is used
* to select the specific bit for a character. */
static u_char pppACCMMask[] = {
0x01,
0x02,
0x04,
0x08,
0x10,
0x20,
0x40,
0x80
};
/***********************************/
/*** PUBLIC FUNCTION DEFINITIONS ***/
/***********************************/
/* Initialize the PPP subsystem. */
struct ppp_settings ppp_settings;
void pppInit(void)
{
struct protent *protp;
int i, j;
memset(&ppp_settings, 0, sizeof(ppp_settings));
ppp_settings.usepeerdns = 1;
pppSetAuth(PPPAUTHTYPE_NONE, NULL, NULL);
magicInit();
for (i = 0; i < NUM_PPP; i++) {
pppControl[i].openFlag = 0;
subnetMask = htonl(0xffffff00);
/*
* Initialize to the standard option set.
*/
for (j = 0; (protp = ppp_protocols[j]) != NULL; ++j)
(*protp->init)(i);
}
#if LINK_STATS
/* Clear the statistics. */
memset(&lwip_stats.link, 0, sizeof(lwip_stats.link));
#endif
}
void pppSetAuth(enum pppAuthType authType, const char *user, const char *passwd)
{
switch(authType) {
case PPPAUTHTYPE_NONE:
default:
#ifdef LWIP_PPP_STRICT_PAP_REJECT
ppp_settings.refuse_pap = 1;
#else
/* some providers request pap and accept an empty login/pw */
ppp_settings.refuse_pap = 0;
#endif
ppp_settings.refuse_chap = 1;
break;
case PPPAUTHTYPE_ANY:
/* Warning: Using PPPAUTHTYPE_ANY might have security consequences.
* RFC 1994 says:
*
* In practice, within or associated with each PPP server, there is a
* database which associates "user" names with authentication
* information ("secrets"). It is not anticipated that a particular
* named user would be authenticated by multiple methods. This would
* make the user vulnerable to attacks which negotiate the least secure
* method from among a set (such as PAP rather than CHAP). If the same
* secret was used, PAP would reveal the secret to be used later with
* CHAP.
*
* Instead, for each user name there should be an indication of exactly
* one method used to authenticate that user name. If a user needs to
* make use of different authentication methods under different
* circumstances, then distinct user names SHOULD be employed, each of
* which identifies exactly one authentication method.
*
*/
ppp_settings.refuse_pap = 0;
ppp_settings.refuse_chap = 0;
break;
case PPPAUTHTYPE_PAP:
ppp_settings.refuse_pap = 0;
ppp_settings.refuse_chap = 1;
break;
case PPPAUTHTYPE_CHAP:
ppp_settings.refuse_pap = 1;
ppp_settings.refuse_chap = 0;
break;
}
if(user) {
strncpy(ppp_settings.user, user, sizeof(ppp_settings.user)-1);
ppp_settings.user[sizeof(ppp_settings.user)-1] = '\0';
} else
ppp_settings.user[0] = '\0';
if(passwd) {
strncpy(ppp_settings.passwd, passwd, sizeof(ppp_settings.passwd)-1);
ppp_settings.passwd[sizeof(ppp_settings.passwd)-1] = '\0';
} else
ppp_settings.passwd[0] = '\0';
}
/* Open a new PPP connection using the given I/O device.
* This initializes the PPP control block but does not
* attempt to negotiate the LCP session. If this port
* connects to a modem, the modem connection must be
* established before calling this.
* Return a new PPP connection descriptor on success or
* an error code (negative) on failure. */
int pppOpen(sio_fd_t fd, void (*linkStatusCB)(void *ctx, int errCode, void *arg), void *linkStatusCtx)
{
PPPControl *pc;
int pd;
/* Find a free PPP session descriptor. Critical region? */
for (pd = 0; pd < NUM_PPP && pppControl[pd].openFlag != 0; pd++);
if (pd >= NUM_PPP)
pd = PPPERR_OPEN;
else
pppControl[pd].openFlag = !0;
/* Launch a deamon thread. */
if (pd >= 0) {
pppControl[pd].openFlag = 1;
lcp_init(pd);
pc = &pppControl[pd];
pc->fd = fd;
pc->kill_link = 0;
pc->sig_hup = 0;
pc->if_up = 0;
pc->errCode = 0;
pc->inState = PDIDLE;
pc->inHead = NULL;
pc->inTail = NULL;
pc->inEscaped = 0;
pc->lastXMit = 0;
#if VJ_SUPPORT > 0
pc->vjEnabled = 0;
vj_compress_init(&pc->vjComp);
#endif
/*
* Default the in and out accm so that escape and flag characters
* are always escaped.
*/
memset(pc->inACCM, 0, sizeof(ext_accm));
pc->inACCM[15] = 0x60;
memset(pc->outACCM, 0, sizeof(ext_accm));
pc->outACCM[15] = 0x60;
pc->linkStatusCB = linkStatusCB;
pc->linkStatusCtx = linkStatusCtx;
sys_thread_new(pppMain, (void*)pd, PPP_THREAD_PRIO);
if(!linkStatusCB) {
while(pd >= 0 && !pc->if_up) {
sys_msleep(500);
if (lcp_phase[pd] == PHASE_DEAD) {
pppClose(pd);
if (pc->errCode)
pd = pc->errCode;
else
pd = PPPERR_CONNECT;
}
}
}
}
return pd;
}
/* Close a PPP connection and release the descriptor.
* Any outstanding packets in the queues are dropped.
* Return 0 on success, an error code on failure. */
int pppClose(int pd)
{
PPPControl *pc = &pppControl[pd];
int st = 0;
/* Disconnect */
pc->kill_link = !0;
pppMainWakeup(pd);
if(!pc->linkStatusCB) {
while(st >= 0 && lcp_phase[pd] != PHASE_DEAD) {
sys_msleep(500);
break;
}
}
return st;
}
/* This function is called when carrier is lost on the PPP channel. */
void pppSigHUP(int pd)
{
PPPControl *pc = &pppControl[pd];
pc->sig_hup = 1;
pppMainWakeup(pd);
}
static void nPut(PPPControl *pc, struct pbuf *nb)
{
struct pbuf *b;
int c;
for(b = nb; b != NULL; b = b->next) {
if((c = sio_write(pc->fd, b->payload, b->len)) != b->len) {
PPPDEBUG((LOG_WARNING,
"PPP nPut: incomplete sio_write(%d,, %u) = %d\n", pc->fd, b->len, c));
#if LINK_STATS
lwip_stats.link.err++;
#endif /* LINK_STATS */
pc->lastXMit = 0; /* prepend PPP_FLAG to next packet */
break;
}
}
pbuf_free(nb);
#if LINK_STATS
lwip_stats.link.xmit++;
#endif /* LINK_STATS */
}
/*
* pppAppend - append given character to end of given pbuf. If outACCM
* is not NULL and the character needs to be escaped, do so.
* If pbuf is full, append another.
* Return the current pbuf.
*/
static struct pbuf *pppAppend(u_char c, struct pbuf *nb, ext_accm *outACCM)
{
struct pbuf *tb = nb;
/* Make sure there is room for the character and an escape code.
* Sure we don't quite fill the buffer if the character doesn't
* get escaped but is one character worth complicating this? */
/* Note: We assume no packet header. */
if (nb && (PBUF_POOL_BUFSIZE - nb->len) < 2) {
tb = pbuf_alloc(PBUF_RAW, 0, PBUF_POOL);
if (tb) {
nb->next = tb;
}
#if LINK_STATS
else {
lwip_stats.link.memerr++;
}
#endif /* LINK_STATS */
nb = tb;
}
if (nb) {
if (outACCM && ESCAPE_P(*outACCM, c)) {
*((u_char*)nb->payload + nb->len++) = PPP_ESCAPE;
*((u_char*)nb->payload + nb->len++) = c ^ PPP_TRANS;
}
else
*((u_char*)nb->payload + nb->len++) = c;
}
return tb;
}
/* Send a packet on the given connection. */
static err_t pppifOutput(struct netif *netif, struct pbuf *pb, struct ip_addr *ipaddr)
{
int pd = (int)netif->state;
u_short protocol = PPP_IP;
PPPControl *pc = &pppControl[pd];
u_int fcsOut = PPP_INITFCS;
struct pbuf *headMB = NULL, *tailMB = NULL, *p;
u_char c;
(void)ipaddr;
/* Validate parameters. */
/* We let any protocol value go through - it can't hurt us
* and the peer will just drop it if it's not accepting it. */
if (pd < 0 || pd >= NUM_PPP || !pc->openFlag || !pb) {
PPPDEBUG((LOG_WARNING, "pppifOutput[%d]: bad parms prot=%d pb=%p\n",
pd, protocol, pb));
#if LINK_STATS
lwip_stats.link.opterr++;
lwip_stats.link.drop++;
#endif
return ERR_ARG;
}
/* Check that the link is up. */
if (lcp_phase[pd] == PHASE_DEAD) {
PPPDEBUG((LOG_ERR, "pppifOutput[%d]: link not up\n", pd));
#if LINK_STATS
lwip_stats.link.rterr++;
lwip_stats.link.drop++;
#endif
return ERR_RTE;
}
/* Grab an output buffer. */
headMB = pbuf_alloc(PBUF_RAW, 0, PBUF_POOL);
if (headMB == NULL) {
PPPDEBUG((LOG_WARNING, "pppifOutput[%d]: first alloc fail\n", pd));
#if LINK_STATS
lwip_stats.link.memerr++;
lwip_stats.link.drop++;
#endif /* LINK_STATS */
return ERR_MEM;
}
#if VJ_SUPPORT > 0
/*
* Attempt Van Jacobson header compression if VJ is configured and
* this is an IP packet.
*/
if (protocol == PPP_IP && pc->vjEnabled) {
switch (vj_compress_tcp(&pc->vjComp, pb)) {
case TYPE_IP:
/* No change...
protocol = PPP_IP_PROTOCOL;
*/
break;
case TYPE_COMPRESSED_TCP:
protocol = PPP_VJC_COMP;
break;
case TYPE_UNCOMPRESSED_TCP:
protocol = PPP_VJC_UNCOMP;
break;
default:
PPPDEBUG((LOG_WARNING, "pppifOutput[%d]: bad IP packet\n", pd));
#if LINK_STATS
lwip_stats.link.proterr++;
lwip_stats.link.drop++;
#endif
pbuf_free(headMB);
return ERR_VAL;
}
}
#endif
tailMB = headMB;
/* Build the PPP header. */
if ((sys_jiffies() - pc->lastXMit) >= PPP_MAXIDLEFLAG)
tailMB = pppAppend(PPP_FLAG, tailMB, NULL);
pc->lastXMit = sys_jiffies();
if (!pc->accomp) {
fcsOut = PPP_FCS(fcsOut, PPP_ALLSTATIONS);
tailMB = pppAppend(PPP_ALLSTATIONS, tailMB, &pc->outACCM);
fcsOut = PPP_FCS(fcsOut, PPP_UI);
tailMB = pppAppend(PPP_UI, tailMB, &pc->outACCM);
}
if (!pc->pcomp || protocol > 0xFF) {
c = (protocol >> 8) & 0xFF;
fcsOut = PPP_FCS(fcsOut, c);
tailMB = pppAppend(c, tailMB, &pc->outACCM);
}
c = protocol & 0xFF;
fcsOut = PPP_FCS(fcsOut, c);
tailMB = pppAppend(c, tailMB, &pc->outACCM);
/* Load packet. */
for(p = pb; p; p = p->next) {
int n;
u_char *sPtr;
sPtr = (u_char*)p->payload;
n = p->len;
while (n-- > 0) {
c = *sPtr++;
/* Update FCS before checking for special characters. */
fcsOut = PPP_FCS(fcsOut, c);
/* Copy to output buffer escaping special characters. */
tailMB = pppAppend(c, tailMB, &pc->outACCM);
}
}
/* Add FCS and trailing flag. */
c = ~fcsOut & 0xFF;
tailMB = pppAppend(c, tailMB, &pc->outACCM);
c = (~fcsOut >> 8) & 0xFF;
tailMB = pppAppend(c, tailMB, &pc->outACCM);
tailMB = pppAppend(PPP_FLAG, tailMB, NULL);
/* If we failed to complete the packet, throw it away. */
if (!tailMB) {
PPPDEBUG((LOG_WARNING,
"pppifOutput[%d]: Alloc err - dropping proto=%d\n",
pd, protocol));
pbuf_free(headMB);
#if LINK_STATS
lwip_stats.link.memerr++;
lwip_stats.link.drop++;
#endif
return ERR_MEM;
}
/* Send it. */
PPPDEBUG((LOG_INFO, "pppifOutput[%d]: proto=0x%04X\n", pd, protocol));
nPut(pc, headMB);
return ERR_OK;
}
/* Get and set parameters for the given connection.
* Return 0 on success, an error code on failure. */
int pppIOCtl(int pd, int cmd, void *arg)
{
PPPControl *pc = &pppControl[pd];
int st = 0;
if (pd < 0 || pd >= NUM_PPP)
st = PPPERR_PARAM;
else {
switch(cmd) {
case PPPCTLG_UPSTATUS: /* Get the PPP up status. */
if (arg)
*(int *)arg = (int)(pc->if_up);
else
st = PPPERR_PARAM;
break;
case PPPCTLS_ERRCODE: /* Set the PPP error code. */
if (arg)
pc->errCode = *(int *)arg;
else
st = PPPERR_PARAM;
break;
case PPPCTLG_ERRCODE: /* Get the PPP error code. */
if (arg)
*(int *)arg = (int)(pc->errCode);
else
st = PPPERR_PARAM;
break;
case PPPCTLG_FD:
if (arg)
*(sio_fd_t *)arg = pc->fd;
else
st = PPPERR_PARAM;
break;
default:
st = PPPERR_PARAM;
break;
}
}
return st;
}
/*
* Return the Maximum Transmission Unit for the given PPP connection.
*/
u_int pppMTU(int pd)
{
PPPControl *pc = &pppControl[pd];
u_int st;
/* Validate parameters. */
if (pd < 0 || pd >= NUM_PPP || !pc->openFlag)
st = 0;
else
st = pc->mtu;
return st;
}
/*
* Write n characters to a ppp link.
* RETURN: >= 0 Number of characters written
* -1 Failed to write to device
*/
int pppWrite(int pd, const u_char *s, int n)
{
PPPControl *pc = &pppControl[pd];
u_char c;
u_int fcsOut = PPP_INITFCS;
struct pbuf *headMB = NULL, *tailMB;
headMB = pbuf_alloc(PBUF_RAW, 0, PBUF_POOL);
if (headMB == NULL) {
#if LINK_STATS
lwip_stats.link.memerr++;
lwip_stats.link.proterr++;
#endif /* LINK_STATS */
return PPPERR_ALLOC;
}
tailMB = headMB;
/* If the link has been idle, we'll send a fresh flag character to
* flush any noise. */
if ((sys_jiffies() - pc->lastXMit) >= PPP_MAXIDLEFLAG)
tailMB = pppAppend(PPP_FLAG, tailMB, NULL);
pc->lastXMit = sys_jiffies();
/* Load output buffer. */
while (n-- > 0) {
c = *s++;
/* Update FCS before checking for special characters. */
fcsOut = PPP_FCS(fcsOut, c);
/* Copy to output buffer escaping special characters. */
tailMB = pppAppend(c, tailMB, &pc->outACCM);
}
/* Add FCS and trailing flag. */
c = ~fcsOut & 0xFF;
tailMB = pppAppend(c, tailMB, &pc->outACCM);
c = (~fcsOut >> 8) & 0xFF;
tailMB = pppAppend(c, tailMB, &pc->outACCM);
tailMB = pppAppend(PPP_FLAG, tailMB, NULL);
/* If we failed to complete the packet, throw it away.
* Otherwise send it. */
if (!tailMB) {
PPPDEBUG((LOG_WARNING,
"pppWrite[%d]: Alloc err - dropping pbuf len=%d\n", pd, headMB->len));
/* "pppWrite[%d]: Alloc err - dropping %d:%.*H", pd, headMB->len, LWIP_MIN(headMB->len * 2, 40), headMB->payload)); */
pbuf_free(headMB);
#if LINK_STATS
lwip_stats.link.memerr++;
lwip_stats.link.proterr++;
#endif /* LINK_STATS */
return PPPERR_ALLOC;
}
PPPDEBUG((LOG_INFO, "pppWrite[%d]: len=%d\n", pd, headMB->len));
/* "pppWrite[%d]: %d:%.*H", pd, headMB->len, LWIP_MIN(headMB->len * 2, 40), headMB->payload)); */
nPut(pc, headMB);
return PPPERR_NONE;
}
/*
* ppp_send_config - configure the transmit characteristics of
* the ppp interface.
*/
void ppp_send_config(
int unit,
int mtu,
u32_t asyncmap,
int pcomp,
int accomp
)
{
PPPControl *pc = &pppControl[unit];
int i;
pc->mtu = mtu;
pc->pcomp = pcomp;
pc->accomp = accomp;
/* Load the ACCM bits for the 32 control codes. */
for (i = 0; i < 32/8; i++)
pc->outACCM[i] = (u_char)((asyncmap >> (8 * i)) & 0xFF);
PPPDEBUG((LOG_INFO, "ppp_send_config[%d]: outACCM=%X %X %X %X\n",
unit,
pc->outACCM[0], pc->outACCM[1], pc->outACCM[2], pc->outACCM[3]));
}
/*
* ppp_set_xaccm - set the extended transmit ACCM for the interface.
*/
void ppp_set_xaccm(int unit, ext_accm *accm)
{
memcpy(pppControl[unit].outACCM, accm, sizeof(ext_accm));
PPPDEBUG((LOG_INFO, "ppp_set_xaccm[%d]: outACCM=%X %X %X %X\n",
unit,
pppControl[unit].outACCM[0],
pppControl[unit].outACCM[1],
pppControl[unit].outACCM[2],
pppControl[unit].outACCM[3]));
}
/*
* ppp_recv_config - configure the receive-side characteristics of
* the ppp interface.
*/
void ppp_recv_config(
int unit,
int mru,
u32_t asyncmap,
int pcomp,
int accomp
)
{
PPPControl *pc = &pppControl[unit];
int i;
(void)accomp;
(void)pcomp;
(void)mru;
/* Load the ACCM bits for the 32 control codes. */
for (i = 0; i < 32 / 8; i++)
pc->inACCM[i] = (u_char)(asyncmap >> (i * 8));
PPPDEBUG((LOG_INFO, "ppp_recv_config[%d]: inACCM=%X %X %X %X\n",
unit,
pc->inACCM[0], pc->inACCM[1], pc->inACCM[2], pc->inACCM[3]));
}
#if 0
/*
* ccp_test - ask kernel whether a given compression method
* is acceptable for use. Returns 1 if the method and parameters
* are OK, 0 if the method is known but the parameters are not OK
* (e.g. code size should be reduced), or -1 if the method is unknown.
*/
int ccp_test(
int unit,
int opt_len,
int for_transmit,
u_char *opt_ptr
)
{
return 0; /* XXX Currently no compression. */
}
/*
* ccp_flags_set - inform kernel about the current state of CCP.
*/
void ccp_flags_set(int unit, int isopen, int isup)
{
/* XXX */
}
/*
* ccp_fatal_error - returns 1 if decompression was disabled as a
* result of an error detected after decompression of a packet,
* 0 otherwise. This is necessary because of patent nonsense.
*/
int ccp_fatal_error(int unit)
{
/* XXX */
return 0;
}
#endif
/*
* get_idle_time - return how long the link has been idle.
*/
int get_idle_time(int u, struct ppp_idle *ip)
{
/* XXX */
(void)u;
(void)ip;
return 0;
}
/*
* Return user specified netmask, modified by any mask we might determine
* for address `addr' (in network byte order).
* Here we scan through the system's list of interfaces, looking for
* any non-point-to-point interfaces which might appear to be on the same
* network as `addr'. If we find any, we OR in their netmask to the
* user-specified netmask.
*/
u32_t GetMask(u32_t addr)
{
u32_t mask, nmask;
htonl(addr);
if (IN_CLASSA(addr)) /* determine network mask for address class */
nmask = IN_CLASSA_NET;
else if (IN_CLASSB(addr))
nmask = IN_CLASSB_NET;
else
nmask = IN_CLASSC_NET;
/* class D nets are disallowed by bad_ip_adrs */
mask = subnetMask | htonl(nmask);
/* XXX
* Scan through the system's network interfaces.
* Get each netmask and OR them into our mask.
*/
return mask;
}
/*
* sifvjcomp - config tcp header compression
*/
int sifvjcomp(
int pd,
int vjcomp,
int cidcomp,
int maxcid
)
{
#if VJ_SUPPORT > 0
PPPControl *pc = &pppControl[pd];
pc->vjEnabled = vjcomp;
pc->vjComp.compressSlot = cidcomp;
pc->vjComp.maxSlotIndex = maxcid;
PPPDEBUG((LOG_INFO, "sifvjcomp: VJ compress enable=%d slot=%d max slot=%d\n",
vjcomp, cidcomp, maxcid));
#endif
return 0;
}
/*
* pppifNetifInit - netif init callback
*/
static err_t pppifNetifInit(struct netif *netif)
{
netif->name[0] = 'p';
netif->name[1] = 'p';
netif->output = pppifOutput;
netif->mtu = pppMTU((int)netif->state);
return ERR_OK;
}
/*
* sifup - Config the interface up and enable IP packets to pass.
*/
int sifup(int pd)
{
PPPControl *pc = &pppControl[pd];
int st = 1;
if (pd < 0 || pd >= NUM_PPP || !pc->openFlag) {
st = 0;
PPPDEBUG((LOG_WARNING, "sifup[%d]: bad parms\n", pd));
} else {
netif_remove(&pc->netif);
if (netif_add(&pc->netif, &pc->addrs.our_ipaddr, &pc->addrs.netmask, &pc->addrs.his_ipaddr, (void *)pd, pppifNetifInit, ip_input)) {
netif_set_up(&pc->netif);
pc->if_up = 1;
pc->errCode = PPPERR_NONE;
PPPDEBUG((LOG_DEBUG, "sifup: unit %d: linkStatusCB=%lx errCode=%d\n", pd, pc->linkStatusCB, pc->errCode));
if(pc->linkStatusCB)
pc->linkStatusCB(pc->linkStatusCtx, pc->errCode, &pc->addrs);
} else {
st = 0;
PPPDEBUG((LOG_ERR, "sifup[%d]: netif_add failed\n", pd));
}
}
return st;
}
/*
* sifnpmode - Set the mode for handling packets for a given NP.
*/
int sifnpmode(int u, int proto, enum NPmode mode)
{
(void)u;
(void)proto;
(void)mode;
return 0;
}
/*
* sifdown - Config the interface down and disable IP.
*/
int sifdown(int pd)
{
PPPControl *pc = &pppControl[pd];
int st = 1;
if (pd < 0 || pd >= NUM_PPP || !pc->openFlag) {
st = 0;
PPPDEBUG((LOG_WARNING, "sifdown[%d]: bad parms\n", pd));
} else {
pc->if_up = 0;
netif_remove(&pc->netif);
PPPDEBUG((LOG_DEBUG, "sifdown: unit %d: linkStatusCB=%lx errCode=%d\n", pd, pc->linkStatusCB, pc->errCode));
if(pc->linkStatusCB)
pc->linkStatusCB(pc->linkStatusCtx, PPPERR_CONNECT, NULL);
}
return st;
}
/*
* sifaddr - Config the interface IP addresses and netmask.
*/
int sifaddr(
int pd, /* Interface unit ??? */
u32_t o, /* Our IP address ??? */
u32_t h, /* His IP address ??? */
u32_t m, /* IP subnet mask ??? */
u32_t ns1, /* Primary DNS */
u32_t ns2 /* Secondary DNS */
)
{
PPPControl *pc = &pppControl[pd];
int st = 1;
if (pd < 0 || pd >= NUM_PPP || !pc->openFlag) {
st = 0;
PPPDEBUG((LOG_WARNING, "sifup[%d]: bad parms\n", pd));
} else {
memcpy(&pc->addrs.our_ipaddr, &o, sizeof(o));
memcpy(&pc->addrs.his_ipaddr, &h, sizeof(h));
memcpy(&pc->addrs.netmask, &m, sizeof(m));
memcpy(&pc->addrs.dns1, &ns1, sizeof(ns1));
memcpy(&pc->addrs.dns2, &ns2, sizeof(ns2));
}
return st;
}
/*
* cifaddr - Clear the interface IP addresses, and delete routes
* through the interface if possible.
*/
int cifaddr(
int pd, /* Interface unit ??? */
u32_t o, /* Our IP address ??? */
u32_t h /* IP broadcast address ??? */
)
{
PPPControl *pc = &pppControl[pd];
int st = 1;
(void)o;
(void)h;
if (pd < 0 || pd >= NUM_PPP || !pc->openFlag) {
st = 0;
PPPDEBUG((LOG_WARNING, "sifup[%d]: bad parms\n", pd));
} else {
IP4_ADDR(&pc->addrs.our_ipaddr, 0,0,0,0);
IP4_ADDR(&pc->addrs.his_ipaddr, 0,0,0,0);
IP4_ADDR(&pc->addrs.netmask, 255,255,255,0);
IP4_ADDR(&pc->addrs.dns1, 0,0,0,0);
IP4_ADDR(&pc->addrs.dns2, 0,0,0,0);
}
return st;
}
/*
* sifdefaultroute - assign a default route through the address given.
*/
int sifdefaultroute(int pd, u32_t l, u32_t g)
{
PPPControl *pc = &pppControl[pd];
int st = 1;
(void)l;
(void)g;
if (pd < 0 || pd >= NUM_PPP || !pc->openFlag) {
st = 0;
PPPDEBUG((LOG_WARNING, "sifup[%d]: bad parms\n", pd));
} else {
netif_set_default(&pc->netif);
}
/* TODO: check how PPP handled the netMask, previously not set by ipSetDefault */
return st;
}
/*
* cifdefaultroute - delete a default route through the address given.
*/
int cifdefaultroute(int pd, u32_t l, u32_t g)
{
PPPControl *pc = &pppControl[pd];
int st = 1;
(void)l;
(void)g;
if (pd < 0 || pd >= NUM_PPP || !pc->openFlag) {
st = 0;
PPPDEBUG((LOG_WARNING, "sifup[%d]: bad parms\n", pd));
} else {
netif_set_default(NULL);
}
return st;
}
void
pppMainWakeup(int pd)
{
PPPDEBUG((LOG_DEBUG, "pppMainWakeup: unit %d\n", pd));
sio_read_abort(pppControl[pd].fd);
}
/* these callbacks are necessary because lcp_* functions
must be called in the same context as pppInput(),
namely the tcpip_thread(), essentially because
they manipulate timeouts which are thread-private
*/
static void
pppStartCB(void *arg)
{
int pd = (int)arg;
PPPDEBUG((LOG_DEBUG, "pppStartCB: unit %d\n", pd));
lcp_lowerup(pd);
lcp_open(pd); /* Start protocol */
}
static void
pppStopCB(void *arg)
{
int pd = (int)arg;
PPPDEBUG((LOG_DEBUG, "pppStopCB: unit %d\n", pd));
lcp_close(pd, "User request");
}
static void
pppHupCB(void *arg)
{
int pd = (int)arg;
PPPDEBUG((LOG_DEBUG, "pppHupCB: unit %d\n", pd));
lcp_lowerdown(pd);
link_terminated(pd);
}
/**********************************/
/*** LOCAL FUNCTION DEFINITIONS ***/
/**********************************/
/* The main PPP process function. This implements the state machine according
* to section 4 of RFC 1661: The Point-To-Point Protocol. */
static void pppMain(void *arg)
{
int pd = (int)arg;
struct pbuf *p;
PPPControl* pc;
pc = &pppControl[pd];
p = pbuf_alloc(PBUF_RAW, PPP_MRU+PPP_HDRLEN, PBUF_RAM);
if(!p) {
LWIP_ASSERT("p != NULL", p);
pc->errCode = PPPERR_ALLOC;
goto out;
}
/*
* Start the connection and handle incoming events (packet or timeout).
*/
PPPDEBUG((LOG_INFO, "pppMain: unit %d: Connecting\n", pd));
tcpip_callback(pppStartCB, arg);
while (lcp_phase[pd] != PHASE_DEAD) {
if (pc->kill_link) {
PPPDEBUG((LOG_DEBUG, "pppMainWakeup: unit %d kill_link -> pppStopCB\n", pd));
pc->errCode = PPPERR_USER;
/* This will leave us at PHASE_DEAD. */
tcpip_callback(pppStopCB, arg);
pc->kill_link = 0;
}
else if (pc->sig_hup) {
PPPDEBUG((LOG_DEBUG, "pppMainWakeup: unit %d sig_hup -> pppHupCB\n", pd));
pc->sig_hup = 0;
tcpip_callback(pppHupCB, arg);
} else {
int c = sio_read(pc->fd, p->payload, p->len);
if(c > 0) {
pppInProc(pd, p->payload, c);
} else {
PPPDEBUG((LOG_DEBUG, "pppMainWakeup: unit %d sio_read len=%d returned %d\n", pd, p->len, c));
sys_msleep(1); /* give other tasks a chance to run */
}
}
}
PPPDEBUG((LOG_INFO, "pppMain: unit %d: PHASE_DEAD\n", pd));
pbuf_free(p);
out:
PPPDEBUG((LOG_DEBUG, "pppMain: unit %d: linkStatusCB=%lx errCode=%d\n", pd, pc->linkStatusCB, pc->errCode));
if(pc->linkStatusCB)
pc->linkStatusCB(pc->linkStatusCtx, pc->errCode ? pc->errCode : PPPERR_PROTOCOL, NULL);
pc->openFlag = 0;
}
static struct pbuf *pppSingleBuf(struct pbuf *p)
{
struct pbuf *q, *b;
u_char *pl;
if(p->tot_len == p->len)
return p;
q = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM);
if(!q) {
PPPDEBUG((LOG_ERR,
"pppSingleBuf: unable to alloc new buf (%d)\n", p->tot_len));
return p; /* live dangerously */
}
for(b = p, pl = q->payload; b != NULL; b = b->next) {
memcpy(pl, b->payload, b->len);
pl += b->len;
}
pbuf_free(p);
return q;
}
struct pppInputHeader {
int unit;
u16_t proto;
};
/*
* Pass the processed input packet to the appropriate handler.
* This function and all handlers run in the context of the tcpip_thread
*/
static void pppInput(void *arg)
{
struct pbuf *nb = (struct pbuf *)arg;
u16_t protocol;
int pd;
pd = ((struct pppInputHeader *)nb->payload)->unit;
protocol = ((struct pppInputHeader *)nb->payload)->proto;
pbuf_header(nb, -(int)sizeof(struct pppInputHeader));
#if LINK_STATS
lwip_stats.link.recv++;
#endif /* LINK_STATS */
/*
* Toss all non-LCP packets unless LCP is OPEN.
* Until we get past the authentication phase, toss all packets
* except LCP, LQR and authentication packets.
*/
if((lcp_phase[pd] <= PHASE_AUTHENTICATE) && (protocol != PPP_LCP)) {
if(!((protocol == PPP_LQR) || (protocol == PPP_PAP) || (protocol == PPP_CHAP)) ||
(lcp_phase[pd] != PHASE_AUTHENTICATE)) {
PPPDEBUG((LOG_INFO, "pppInput: discarding proto 0x%04X in phase %d\n", protocol, lcp_phase[pd]));
goto drop;
}
}
switch(protocol) {
case PPP_VJC_COMP: /* VJ compressed TCP */
#if VJ_SUPPORT > 0
PPPDEBUG((LOG_INFO, "pppInput[%d]: vj_comp in pbuf len=%d\n", pd, nb->len));
/*
* Clip off the VJ header and prepend the rebuilt TCP/IP header and
* pass the result to IP.
*/
if (vj_uncompress_tcp(&nb, &pppControl[pd].vjComp) >= 0) {
if (pppControl[pd].netif.input != NULL) {
pppControl[pd].netif.input(nb, &pppControl[pd].netif);
}
return;
}
/* Something's wrong so drop it. */
PPPDEBUG((LOG_WARNING, "pppInput[%d]: Dropping VJ compressed\n", pd));
#else
/* No handler for this protocol so drop the packet. */
PPPDEBUG((LOG_INFO, "pppInput[%d]: drop VJ Comp in %d:%s\n", pd, nb->len, nb->payload));
#endif /* VJ_SUPPORT > 0 */
break;
case PPP_VJC_UNCOMP: /* VJ uncompressed TCP */
#if VJ_SUPPORT > 0
PPPDEBUG((LOG_INFO, "pppInput[%d]: vj_un in pbuf len=%d\n", pd, nb->len));
/*
* Process the TCP/IP header for VJ header compression and then pass
* the packet to IP.
*/
if (vj_uncompress_uncomp(nb, &pppControl[pd].vjComp) >= 0) {
if (pppControl[pd].netif.input != NULL) {
pppControl[pd].netif.input(nb, &pppControl[pd].netif);
}
return;
}
/* Something's wrong so drop it. */
PPPDEBUG((LOG_WARNING, "pppInput[%d]: Dropping VJ uncompressed\n", pd));
#else
/* No handler for this protocol so drop the packet. */
PPPDEBUG((LOG_INFO,
"pppInput[%d]: drop VJ UnComp in %d:.*H\n",
pd, nb->len, LWIP_MIN(nb->len * 2, 40), nb->payload));
#endif /* VJ_SUPPORT > 0 */
break;
case PPP_IP: /* Internet Protocol */
PPPDEBUG((LOG_INFO, "pppInput[%d]: ip in pbuf len=%d\n", pd, nb->len));
if (pppControl[pd].netif.input != NULL) {
pppControl[pd].netif.input(nb, &pppControl[pd].netif);
}
return;
default:
{
struct protent *protp;
int i;
/*
* Upcall the proper protocol input routine.
*/
for (i = 0; (protp = ppp_protocols[i]) != NULL; ++i) {
if (protp->protocol == protocol && protp->enabled_flag) {
PPPDEBUG((LOG_INFO, "pppInput[%d]: %s len=%d\n", pd, protp->name, nb->len));
nb = pppSingleBuf(nb);
(*protp->input)(pd, nb->payload, nb->len);
goto out;
}
}
/* No handler for this protocol so reject the packet. */
PPPDEBUG((LOG_INFO, "pppInput[%d]: rejecting unsupported proto 0x%04X len=%d\n", pd, protocol, nb->len));
pbuf_header(nb, sizeof(protocol));
#if BYTE_ORDER == LITTLE_ENDIAN
protocol = htons(protocol);
memcpy(nb->payload, &protocol, sizeof(protocol));
#endif
lcp_sprotrej(pd, nb->payload, nb->len);
}
break;
}
drop:
#if LINK_STATS
lwip_stats.link.drop++;
#endif
out:
pbuf_free(nb);
return;
}
/*
* Drop the input packet.
*/
static void pppDrop(PPPControl *pc)
{
if (pc->inHead != NULL) {
#if 0
PPPDEBUG((LOG_INFO, "pppDrop: %d:%.*H\n", pc->inHead->len, min(60, pc->inHead->len * 2), pc->inHead->payload));
#endif
PPPDEBUG((LOG_INFO, "pppDrop: pbuf len=%d\n", pc->inHead->len));
if (pc->inTail && (pc->inTail != pc->inHead))
pbuf_free(pc->inTail);
pbuf_free(pc->inHead);
pc->inHead = NULL;
pc->inTail = NULL;
}
#if VJ_SUPPORT > 0
vj_uncompress_err(&pc->vjComp);
#endif
#if LINK_STATS
lwip_stats.link.drop++;
#endif /* LINK_STATS */
}
/*
* Process a received octet string.
*/
static void pppInProc(int pd, u_char *s, int l)
{
PPPControl *pc = &pppControl[pd];
struct pbuf *nextNBuf;
u_char curChar;
PPPDEBUG((LOG_DEBUG, "pppInProc[%d]: got %d bytes\n", pd, l));
while (l-- > 0) {
curChar = *s++;
/* Handle special characters. */
if (ESCAPE_P(pc->inACCM, curChar)) {
/* Check for escape sequences. */
/* XXX Note that this does not handle an escaped 0x5d character which
* would appear as an escape character. Since this is an ASCII ']'
* and there is no reason that I know of to escape it, I won't complicate
* the code to handle this case. GLL */
if (curChar == PPP_ESCAPE)
pc->inEscaped = 1;
/* Check for the flag character. */
else if (curChar == PPP_FLAG) {
/* If this is just an extra flag character, ignore it. */
if (pc->inState <= PDADDRESS)
;
/* If we haven't received the packet header, drop what has come in. */
else if (pc->inState < PDDATA) {
PPPDEBUG((LOG_WARNING,
"pppInProc[%d]: Dropping incomplete packet %d\n",
pd, pc->inState));
#if LINK_STATS
lwip_stats.link.lenerr++;
#endif
pppDrop(pc);
}
/* If the fcs is invalid, drop the packet. */
else if (pc->inFCS != PPP_GOODFCS) {
PPPDEBUG((LOG_INFO,
"pppInProc[%d]: Dropping bad fcs 0x%04X proto=0x%04X\n",
pd, pc->inFCS, pc->inProtocol));
#if LINK_STATS
lwip_stats.link.chkerr++;
#endif
pppDrop(pc);
}
/* Otherwise it's a good packet so pass it on. */
else {
/* Trim off the checksum. */
if(pc->inTail->len >= 2) {
pc->inTail->len -= 2;
pc->inTail->tot_len = pc->inTail->len;
if (pc->inTail != pc->inHead) {
pbuf_cat(pc->inHead, pc->inTail);
}
} else {
pc->inTail->tot_len = pc->inTail->len;
if (pc->inTail != pc->inHead) {
pbuf_cat(pc->inHead, pc->inTail);
}
pbuf_realloc(pc->inHead, pc->inHead->tot_len - 2);
}
/* Dispatch the packet thereby consuming it. */
if(tcpip_callback(pppInput, pc->inHead) != ERR_OK) {
PPPDEBUG((LOG_ERR,
"pppInProc[%d]: tcpip_callback() failed, dropping packet\n", pd));
pbuf_free(pc->inHead);
#if LINK_STATS
lwip_stats.link.drop++;
#endif
}
pc->inHead = NULL;
pc->inTail = NULL;
}
/* Prepare for a new packet. */
pc->inFCS = PPP_INITFCS;
pc->inState = PDADDRESS;
pc->inEscaped = 0;
}
/* Other characters are usually control characters that may have
* been inserted by the physical layer so here we just drop them. */
else {
PPPDEBUG((LOG_WARNING,
"pppInProc[%d]: Dropping ACCM char <%d>\n", pd, curChar));
}
}
/* Process other characters. */
else {
/* Unencode escaped characters. */
if (pc->inEscaped) {
pc->inEscaped = 0;
curChar ^= PPP_TRANS;
}
/* Process character relative to current state. */
switch(pc->inState) {
case PDIDLE: /* Idle state - waiting. */
/* Drop the character if it's not 0xff
* we would have processed a flag character above. */
if (curChar != PPP_ALLSTATIONS) {
break;
}
/* Fall through */
case PDSTART: /* Process start flag. */
/* Prepare for a new packet. */
pc->inFCS = PPP_INITFCS;
/* Fall through */
case PDADDRESS: /* Process address field. */
if (curChar == PPP_ALLSTATIONS) {
pc->inState = PDCONTROL;
break;
}
/* Else assume compressed address and control fields so
* fall through to get the protocol... */
case PDCONTROL: /* Process control field. */
/* If we don't get a valid control code, restart. */
if (curChar == PPP_UI) {
pc->inState = PDPROTOCOL1;
break;
}
#if 0
else {
PPPDEBUG((LOG_WARNING,
"pppInProc[%d]: Invalid control <%d>\n", pd, curChar));
pc->inState = PDSTART;
}
#endif
case PDPROTOCOL1: /* Process protocol field 1. */
/* If the lower bit is set, this is the end of the protocol
* field. */
if (curChar & 1) {
pc->inProtocol = curChar;
pc->inState = PDDATA;
}
else {
pc->inProtocol = (u_int)curChar << 8;
pc->inState = PDPROTOCOL2;
}
break;
case PDPROTOCOL2: /* Process protocol field 2. */
pc->inProtocol |= curChar;
pc->inState = PDDATA;
break;
case PDDATA: /* Process data byte. */
/* Make space to receive processed data. */
if (pc->inTail == NULL || pc->inTail->len == PBUF_POOL_BUFSIZE) {
if(pc->inTail) {
pc->inTail->tot_len = pc->inTail->len;
if (pc->inTail != pc->inHead) {
pbuf_cat(pc->inHead, pc->inTail);
}
}
/* If we haven't started a packet, we need a packet header. */
nextNBuf = pbuf_alloc(PBUF_RAW, 0, PBUF_POOL);
if (nextNBuf == NULL) {
/* No free buffers. Drop the input packet and let the
* higher layers deal with it. Continue processing
* the received pbuf chain in case a new packet starts. */
PPPDEBUG((LOG_ERR, "pppInProc[%d]: NO FREE MBUFS!\n", pd));
#if LINK_STATS
lwip_stats.link.memerr++;
#endif /* LINK_STATS */
pppDrop(pc);
pc->inState = PDSTART; /* Wait for flag sequence. */
break;
}
if (pc->inHead == NULL) {
struct pppInputHeader *pih = nextNBuf->payload;
pih->unit = pd;
pih->proto = pc->inProtocol;
nextNBuf->len += sizeof(*pih);
pc->inHead = nextNBuf;
}
pc->inTail = nextNBuf;
}
/* Load character into buffer. */
((u_char*)pc->inTail->payload)[pc->inTail->len++] = curChar;
break;
}
/* update the frame check sequence number. */
pc->inFCS = PPP_FCS(pc->inFCS, curChar);
}
}
avRandomize();
}
#endif /* PPP_SUPPORT */
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