66 files changed, 15542 insertions, 1 deletions
diff --git a/src/ppp.c b/src/ppp.c new file mode 100755 index 0000000..543ba71 --- a/dev/null +++ b/src/ppp.c @@ -0,0 +1,262 @@ +/*********************************************************************** +* +* ppp.c +* +* Implementation of user-space PPPoE redirector for Linux. +* +* Functions for talking to PPP daemon +* +* Copyright (C) 2000 by Roaring Penguin Software Inc. +* +* This program may be distributed according to the terms of the GNU +* General Public License, version 2 or (at your option) any later version. +* +* LIC: GPL +* +***********************************************************************/ + +static char const RCSID[] = +"$Id$"; + +#include "pppoe.h" + +#ifdef HAVE_SYSLOG_H +#include <syslog.h> +#include <android/log.h> +#define syslog(prio, fmt...) \ + __android_log_print(prio, "PPPOE", fmt) +#endif + +#include <string.h> +#include <errno.h> +#include <stdlib.h> + +#ifdef HAVE_SYS_UIO_H +#include <sys/uio.h> +#endif + +#ifdef HAVE_UNISTD_H +#include <unistd.h> +#endif + +#ifdef HAVE_N_HDLC +#ifndef N_HDLC +#include <linux/termios.h> +#endif +#endif + +static int PPPState; +static int PPPPacketSize; +static unsigned char PPPXorValue; + +static UINT16_t const 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 +}; + +/********************************************************************** +*%FUNCTION: syncReadFromPPP +*%ARGUMENTS: +* conn -- PPPoEConnection structure +* packet -- buffer in which to place PPPoE packet +*%RETURNS: +* Nothing +*%DESCRIPTION: +* Reads from a synchronous PPP device and builds and transmits a PPPoE +* packet +***********************************************************************/ +void +syncReadFromPPP(PPPoEConnection *conn, PPPoEPacket *packet) +{ + int r; +#ifndef HAVE_N_HDLC + struct iovec vec[2]; + unsigned char dummy[2]; + vec[0].iov_base = (void *) dummy; + vec[0].iov_len = 2; + vec[1].iov_base = (void *) packet->payload; + vec[1].iov_len = ETH_DATA_LEN - PPPOE_OVERHEAD; + + /* Use scatter-read to throw away the PPP frame address bytes */ + r = readv(0, vec, 2); +#else + /* Bloody hell... readv doesn't work with N_HDLC line discipline... GRR! */ + unsigned char buf[ETH_DATA_LEN - PPPOE_OVERHEAD + 2]; + r = read(0, buf, ETH_DATA_LEN - PPPOE_OVERHEAD + 2); + if (r >= 2) { + memcpy(packet->payload, buf+2, r-2); + } +#endif + if (r < 0) { + /* Catch the Linux "select" bug */ + if (errno == EAGAIN) { + rp_fatal("Linux select bug hit! This message is harmless, but please ask the Linux kernel developers to fix it."); + } + fatalSys("read (syncReadFromPPP)"); + } + if (r == 0) { + syslog(LOG_INFO, "end-of-file in syncReadFromPPP"); + sendPADT(conn, "RP-PPPoE: EOF in syncReadFromPPP"); + exit(0); + } + + if (r < 2) { + rp_fatal("too few characters read from PPP (syncReadFromPPP)"); + } + + sendSessionPacket(conn, packet, r-2); +} + +/********************************************************************** +*%FUNCTION: initPPP +*%ARGUMENTS: +* None +*%RETURNS: +* Nothing +*%DESCRIPTION: +* Initializes the PPP state machine +***********************************************************************/ +void +initPPP(void) +{ + PPPState = STATE_WAITFOR_FRAME_ADDR; + PPPPacketSize = 0; + PPPXorValue = 0; + +} +/********************************************************************** +*%FUNCTION: asyncReadFromPPP +*%ARGUMENTS: +* conn -- PPPoEConnection structure +* packet -- buffer in which to place PPPoE packet +*%RETURNS: +* Nothing +*%DESCRIPTION: +* Reads from an async PPP device and builds a PPPoE packet to transmit +***********************************************************************/ +void +asyncReadFromPPP(PPPoEConnection *conn, PPPoEPacket *packet) +{ + unsigned char buf[READ_CHUNK]; + unsigned char *ptr = buf; + unsigned char c; + + int r; + + r = read(0, buf, READ_CHUNK); + if (r < 0) { + fatalSys("read (asyncReadFromPPP)"); + } + + if (r == 0) { + syslog(LOG_INFO, "end-of-file in asyncReadFromPPP"); + sendPADT(conn, "RP-PPPoE: EOF in asyncReadFromPPP"); + exit(0); + } + + while(r) { + if (PPPState == STATE_WAITFOR_FRAME_ADDR) { + while(r) { + --r; + if (*ptr++ == FRAME_ADDR) { + PPPState = STATE_DROP_PROTO; + break; + } + } + } + + /* Still waiting... */ + if (PPPState == STATE_WAITFOR_FRAME_ADDR) return; + + while(r && PPPState == STATE_DROP_PROTO) { + --r; + if (*ptr++ == (FRAME_CTRL ^ FRAME_ENC)) { + PPPState = STATE_BUILDING_PACKET; + } + } + + if (PPPState == STATE_DROP_PROTO) return; + + /* Start building frame */ + while(r && PPPState == STATE_BUILDING_PACKET) { + --r; + c = *ptr++; + switch(c) { + case FRAME_ESC: + PPPXorValue = FRAME_ENC; + break; + case FRAME_FLAG: + if (PPPPacketSize < 2) { + rp_fatal("Packet too short from PPP (asyncReadFromPPP)"); + } + sendSessionPacket(conn, packet, PPPPacketSize-2); + PPPPacketSize = 0; + PPPXorValue = 0; + PPPState = STATE_WAITFOR_FRAME_ADDR; + break; + default: + if (PPPPacketSize >= ETH_DATA_LEN - 4) { + syslog(LOG_ERR, "Packet too big! Check MTU on PPP interface"); + PPPPacketSize = 0; + PPPXorValue = 0; + PPPState = STATE_WAITFOR_FRAME_ADDR; + } else { + packet->payload[PPPPacketSize++] = c ^ PPPXorValue; + PPPXorValue = 0; + } + } + } + } +} + +/********************************************************************** +*%FUNCTION: pppFCS16 +*%ARGUMENTS: +* fcs -- current fcs +* cp -- a buffer's worth of data +* len -- length of buffer "cp" +*%RETURNS: +* A new FCS +*%DESCRIPTION: +* Updates the PPP FCS. +***********************************************************************/ +UINT16_t +pppFCS16(UINT16_t fcs, + unsigned char * cp, + int len) +{ + while (len--) + fcs = (fcs >> 8) ^ fcstab[(fcs ^ *cp++) & 0xff]; + + return (fcs); +} |