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[/] [openrisc/] [trunk/] [rtos/] [freertos-6.1.1/] [Demo/] [lwIP_Demo_Rowley_ARM7/] [lwip-1.1.0/] [src/] [netif/] [ppp/] [ppp.c] - Rev 583
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/***************************************************************************** * 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)) { 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) { 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) { 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)); 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 */