From: Paul Mackerras Date: Mon, 1 Jan 1996 23:10:09 +0000 (+0000) Subject: Added functions for demand-dial support X-Git-Tag: RELEASE_2_3_6~534 X-Git-Url: http://git.ozlabs.org/?p=ppp.git;a=commitdiff_plain;h=a70f63bce70443ea411421f41cb27abfc62a8981 Added functions for demand-dial support --- diff --git a/pppd/demand.c b/pppd/demand.c new file mode 100644 index 0000000..21a1f07 --- /dev/null +++ b/pppd/demand.c @@ -0,0 +1,296 @@ +/* + * auth.c - PPP authentication and phase control. + * + * Copyright (c) 1993 The Australian National 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 the Australian National 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 MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. + */ + +#ifndef lint +static char rcsid[] = "$Id: demand.c,v 1.1 1996/01/01 23:10:09 paulus Exp $"; +#endif + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "pppd.h" +#include "fsm.h" +#include "ipcp.h" +#include "lcp.h" + +char *frame; +int framelen; +int framemax; +int escape_flag; +int flush_flag; +int fcs; + +struct packet { + int length; + struct packet *next; + unsigned char data[1]; +}; + +struct packet *pend_q; +struct packet *pend_qtail; + +/* + * demand_conf - configure the interface for doing dial-on-demand. + */ +void +demand_conf() +{ + int i; + struct protent *protp; + +/* framemax = lcp_allowoptions[0].mru; + if (framemax < PPP_MRU) */ + framemax = PPP_MRU; + framemax += PPP_HDRLEN + PPP_FCSLEN; + frame = malloc(framemax); + if (frame == NULL) + novm("demand frame"); + framelen = 0; + pend_q = NULL; + escape_flag = 0; + flush_flag = 0; + fcs = PPP_INITFCS; + + ppp_send_config(0, PPP_MRU, (u_int32_t) 0, 0, 0); + ppp_recv_config(0, PPP_MRU, (u_int32_t) 0, 0, 0); + + /* + * Call the demand_conf procedure for each protocol that's got one. + */ + for (i = 0; (protp = protocols[i]) != NULL; ++i) + if (protp->enabled_flag && protp->demand_conf != NULL) + if (!((*protp->demand_conf)(0))) + die(1); +} + + +/* + * demand_block - set each network protocol to block further packets. + */ +void +demand_block() +{ + int i; + struct protent *protp; + + for (i = 0; (protp = protocols[i]) != NULL; ++i) + if (protp->enabled_flag && protp->demand_conf != NULL) + sifnpmode(0, protp->protocol, NPMODE_QUEUE); + get_loop_output(); +} + +/* + * demand_discard - set each network protocol to discard packets + * with an error. + */ +void +demand_discard() +{ + struct packet *pkt, *nextpkt; + int i; + struct protent *protp; + + for (i = 0; (protp = protocols[i]) != NULL; ++i) + if (protp->enabled_flag && protp->demand_conf != NULL) + sifnpmode(0, protp->protocol, NPMODE_ERROR); + get_loop_output(); + + /* discard all saved packets */ + for (pkt = pend_q; pkt != NULL; pkt = nextpkt) { + nextpkt = pkt->next; + free(pkt); + } + pend_q = NULL; + framelen = 0; + flush_flag = 0; + escape_flag = 0; + fcs = PPP_INITFCS; +} + +/* + * demand_unblock - set each enabled network protocol to pass packets. + */ +void +demand_unblock() +{ + int i; + struct protent *protp; + + for (i = 0; (protp = protocols[i]) != NULL; ++i) + if (protp->enabled_flag && protp->demand_conf != NULL) + sifnpmode(0, protp->protocol, NPMODE_PASS); +} + +/* + * FCS lookup table as calculated by genfcstab. + */ +static 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 +}; + +/* + * loop_chars - process characters received from the loopback. + * Calls loop_frame when a complete frame has been accumulated. + * Return value is 1 if we need to bring up the link, 0 otherwise. + */ +int +loop_chars(p, n) + unsigned char *p; + int n; +{ + int c, rv; + + rv = 0; + for (; n > 0; --n) { + c = *p++; + if (c == PPP_FLAG) { + if (!escape_flag && !flush_flag + && framelen > 2 && fcs == PPP_GOODFCS) { + framelen -= 2; + if (loop_frame(frame, framelen)) + rv = 1; + } + framelen = 0; + flush_flag = 0; + escape_flag = 0; + fcs = PPP_INITFCS; + continue; + } + if (flush_flag) + continue; + if (escape_flag) { + c ^= PPP_TRANS; + escape_flag = 0; + } else if (c == PPP_ESCAPE) { + escape_flag = 1; + continue; + } + if (framelen >= framemax) { + flush_flag = 1; + continue; + } + frame[framelen++] = c; + fcs = PPP_FCS(fcs, c); + } + return rv; +} + +/* + * loop_frame - given a frame obtained from the loopback, + * decide whether to bring up the link or not, and, if we want + * to transmit this frame later, put it on the pending queue. + * Return value is 1 if we need to bring up the link, 0 otherwise. + */ +int +loop_frame(frame, len) + unsigned char *frame; + int len; +{ + struct packet *pkt; + + if (len < PPP_HDRLEN) + return 0; + if (PPP_PROTOCOL(frame) != PPP_IP) + return 0; + pkt = (struct packet *) malloc(sizeof(struct packet) + len); + if (pkt != NULL) { + pkt->length = len; + pkt->next = NULL; + memcpy(pkt->data, frame, len); + if (pend_q == NULL) + pend_q = pkt; + else + pend_qtail->next = pkt; + pend_qtail = pkt; + } + return 1; +} + +/* + * demand_rexmit - Resend all those frames which we got via the + * loopback, now that the real serial link is up. + */ +void +demand_rexmit(proto) + int proto; +{ + struct packet *pkt, *prev, *nextpkt; + + prev = NULL; + pkt = pend_q; + pend_q = NULL; + for (; pkt != NULL; pkt = nextpkt) { + if (PPP_PROTOCOL(pkt->data) == proto) { + output(0, pkt->data, pkt->length); + nextpkt = pkt->next; + free(pkt); + } else { + if (prev == NULL) + pend_q = pkt; + else + prev->next = pkt; + prev = pkt; + } + } + pend_qtail = prev; +}