/* * NET3: A (fairly minimal) implementation of synchronous PPP for Linux * as well as a CISCO HDLC implementation. See the copyright * message below for the original source. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the license, or (at your option) any later version. * * Note however. This code is also used in a different form by FreeBSD. * Therefore when making any non OS specific change please consider * contributing it back to the original author under the terms * below in addition. * -- Alan * * Port for Linux-2.1 by Jan "Yenya" Kasprzak */ /* * Synchronous PPP/Cisco link level subroutines. * Keepalive protocol implemented in both Cisco and PPP modes. * * Copyright (C) 1994 Cronyx Ltd. * Author: Serge Vakulenko, * * This software is distributed with NO WARRANTIES, not even the implied * warranties for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * * Authors grant any other persons or organisations permission to use * or modify this software as long as this message is kept with the software, * all derivative works or modified versions. * * Version 1.9, Wed Oct 4 18:58:15 MSK 1995 * * $Id: syncppp.c,v 1.1.1.1 2003/06/23 22:18:31 jharrell Exp $ */ #undef DEBUG #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define MAXALIVECNT 6 /* max. alive packets */ #define PPP_ALLSTATIONS 0xff /* All-Stations broadcast address */ #define PPP_UI 0x03 /* Unnumbered Information */ #define PPP_IP 0x0021 /* Internet Protocol */ #define PPP_ISO 0x0023 /* ISO OSI Protocol */ #define PPP_XNS 0x0025 /* Xerox NS Protocol */ #define PPP_IPX 0x002b /* Novell IPX Protocol */ #define PPP_LCP 0xc021 /* Link Control Protocol */ #define PPP_IPCP 0x8021 /* Internet Protocol Control Protocol */ #define LCP_CONF_REQ 1 /* PPP LCP configure request */ #define LCP_CONF_ACK 2 /* PPP LCP configure acknowledge */ #define LCP_CONF_NAK 3 /* PPP LCP configure negative ack */ #define LCP_CONF_REJ 4 /* PPP LCP configure reject */ #define LCP_TERM_REQ 5 /* PPP LCP terminate request */ #define LCP_TERM_ACK 6 /* PPP LCP terminate acknowledge */ #define LCP_CODE_REJ 7 /* PPP LCP code reject */ #define LCP_PROTO_REJ 8 /* PPP LCP protocol reject */ #define LCP_ECHO_REQ 9 /* PPP LCP echo request */ #define LCP_ECHO_REPLY 10 /* PPP LCP echo reply */ #define LCP_DISC_REQ 11 /* PPP LCP discard request */ #define LCP_OPT_MRU 1 /* maximum receive unit */ #define LCP_OPT_ASYNC_MAP 2 /* async control character map */ #define LCP_OPT_AUTH_PROTO 3 /* authentication protocol */ #define LCP_OPT_QUAL_PROTO 4 /* quality protocol */ #define LCP_OPT_MAGIC 5 /* magic number */ #define LCP_OPT_RESERVED 6 /* reserved */ #define LCP_OPT_PROTO_COMP 7 /* protocol field compression */ #define LCP_OPT_ADDR_COMP 8 /* address/control field compression */ #define IPCP_CONF_REQ LCP_CONF_REQ /* PPP IPCP configure request */ #define IPCP_CONF_ACK LCP_CONF_ACK /* PPP IPCP configure acknowledge */ #define IPCP_CONF_NAK LCP_CONF_NAK /* PPP IPCP configure negative ack */ #define IPCP_CONF_REJ LCP_CONF_REJ /* PPP IPCP configure reject */ #define IPCP_TERM_REQ LCP_TERM_REQ /* PPP IPCP terminate request */ #define IPCP_TERM_ACK LCP_TERM_ACK /* PPP IPCP terminate acknowledge */ #define IPCP_CODE_REJ LCP_CODE_REJ /* PPP IPCP code reject */ #define CISCO_MULTICAST 0x8f /* Cisco multicast address */ #define CISCO_UNICAST 0x0f /* Cisco unicast address */ #define CISCO_KEEPALIVE 0x8035 /* Cisco keepalive protocol */ #define CISCO_ADDR_REQ 0 /* Cisco address request */ #define CISCO_ADDR_REPLY 1 /* Cisco address reply */ #define CISCO_KEEPALIVE_REQ 2 /* Cisco keepalive request */ struct ppp_header { u8 address; u8 control; u16 protocol; }; #define PPP_HEADER_LEN sizeof (struct ppp_header) struct lcp_header { u8 type; u8 ident; u16 len; }; #define LCP_HEADER_LEN sizeof (struct lcp_header) struct cisco_packet { u32 type; u32 par1; u32 par2; u16 rel; u16 time0; u16 time1; }; #define CISCO_PACKET_LEN 18 #define CISCO_BIG_PACKET_LEN 20 static struct sppp *spppq; static struct timer_list sppp_keepalive_timer; static spinlock_t spppq_lock = SPIN_LOCK_UNLOCKED; static void sppp_keepalive (unsigned long dummy); static void sppp_cp_send (struct sppp *sp, u16 proto, u8 type, u8 ident, u16 len, void *data); static void sppp_cisco_send (struct sppp *sp, int type, long par1, long par2); static void sppp_lcp_input (struct sppp *sp, struct sk_buff *m); static void sppp_cisco_input (struct sppp *sp, struct sk_buff *m); static void sppp_ipcp_input (struct sppp *sp, struct sk_buff *m); static void sppp_lcp_open (struct sppp *sp); static void sppp_ipcp_open (struct sppp *sp); static int sppp_lcp_conf_parse_options (struct sppp *sp, struct lcp_header *h, int len, u32 *magic); static void sppp_cp_timeout (unsigned long arg); static char *sppp_lcp_type_name (u8 type); static char *sppp_ipcp_type_name (u8 type); static void sppp_print_bytes (u8 *p, u16 len); static int debug; /* * Interface down stub */ static void if_down(struct net_device *dev) { struct sppp *sp = (struct sppp *)sppp_of(dev); sp->pp_link_state=SPPP_LINK_DOWN; } /* * Timeout routine activations. */ static void sppp_set_timeout(struct sppp *p,int s) { if (! (p->pp_flags & PP_TIMO)) { init_timer(&p->pp_timer); p->pp_timer.function=sppp_cp_timeout; p->pp_timer.expires=jiffies+s*HZ; p->pp_timer.data=(unsigned long)p; p->pp_flags |= PP_TIMO; add_timer(&p->pp_timer); } } static void sppp_clear_timeout(struct sppp *p) { if (p->pp_flags & PP_TIMO) { del_timer(&p->pp_timer); p->pp_flags &= ~PP_TIMO; } } /** * sppp_input - receive and process a WAN PPP frame * @skb: The buffer to process * @dev: The device it arrived on * * This can be called directly by cards that do not have * timing constraints but is normally called from the network layer * after interrupt servicing to process frames queued via netif_rx(). * * We process the options in the card. If the frame is destined for * the protocol stacks then it requeues the frame for the upper level * protocol. If it is a control from it is processed and discarded * here. */ void sppp_input (struct net_device *dev, struct sk_buff *skb) { struct ppp_header *h; struct sppp *sp = (struct sppp *)sppp_of(dev); skb->dev=dev; skb->mac.raw=skb->data; if (dev->flags & IFF_RUNNING) { /* Count received bytes, add FCS and one flag */ sp->ibytes+= skb->len + 3; sp->ipkts++; } if (skb->len <= PPP_HEADER_LEN) { /* Too small packet, drop it. */ if (sp->pp_flags & PP_DEBUG) printk (KERN_DEBUG "%s: input packet is too small, %d bytes\n", dev->name, skb->len); drop: kfree_skb(skb); return; } /* Get PPP header. */ h = (struct ppp_header *)skb->data; skb_pull(skb,sizeof(struct ppp_header)); switch (h->address) { default: /* Invalid PPP packet. */ invalid: if (sp->pp_flags & PP_DEBUG) printk (KERN_WARNING "%s: invalid input packet <0x%x 0x%x 0x%x>\n", dev->name, h->address, h->control, ntohs (h->protocol)); goto drop; case PPP_ALLSTATIONS: if (h->control != PPP_UI) goto invalid; if (sp->pp_flags & PP_CISCO) { if (sp->pp_flags & PP_DEBUG) printk (KERN_WARNING "%s: PPP packet in Cisco mode <0x%x 0x%x 0x%x>\n", dev->name, h->address, h->control, ntohs (h->protocol)); goto drop; } switch (ntohs (h->protocol)) { default: if (sp->lcp.state == LCP_STATE_OPENED) sppp_cp_send (sp, PPP_LCP, LCP_PROTO_REJ, ++sp->pp_seq, skb->len + 2, &h->protocol); if (sp->pp_flags & PP_DEBUG) printk (KERN_WARNING "%s: invalid input protocol <0x%x 0x%x 0x%x>\n", dev->name, h->address, h->control, ntohs (h->protocol)); goto drop; case PPP_LCP: sppp_lcp_input (sp, skb); kfree_skb(skb); return; case PPP_IPCP: if (sp->lcp.state == LCP_STATE_OPENED) sppp_ipcp_input (sp, skb); else printk(KERN_DEBUG "IPCP when still waiting LCP finish.\n"); kfree_skb(skb); return; case PPP_IP: if (sp->ipcp.state == IPCP_STATE_OPENED) { if(sp->pp_flags&PP_DEBUG) printk(KERN_DEBUG "Yow an IP frame.\n"); skb->protocol=htons(ETH_P_IP); netif_rx(skb); return; } break; #ifdef IPX case PPP_IPX: /* IPX IPXCP not implemented yet */ if (sp->lcp.state == LCP_STATE_OPENED) { skb->protocol=htons(ETH_P_IPX); netif_rx(skb); return; } break; #endif } break; case CISCO_MULTICAST: case CISCO_UNICAST: /* Don't check the control field here (RFC 1547). */ if (! (sp->pp_flags & PP_CISCO)) { if (sp->pp_flags & PP_DEBUG) printk (KERN_WARNING "%s: Cisco packet in PPP mode <0x%x 0x%x 0x%x>\n", dev->name, h->address, h->control, ntohs (h->protocol)); goto drop; } switch (ntohs (h->protocol)) { default: goto invalid; case CISCO_KEEPALIVE: sppp_cisco_input (sp, skb); kfree_skb(skb); return; #ifdef CONFIG_INET case ETH_P_IP: skb->protocol=htons(ETH_P_IP); netif_rx(skb); return; #endif #ifdef CONFIG_IPX case ETH_P_IPX: skb->protocol=htons(ETH_P_IPX); netif_rx(skb); return; #endif } break; } kfree_skb(skb); } EXPORT_SYMBOL(sppp_input); /* * Handle transmit packets. */ static int sppp_hard_header(struct sk_buff *skb, struct net_device *dev, __u16 type, void *daddr, void *saddr, unsigned int len) { struct sppp *sp = (struct sppp *)sppp_of(dev); struct ppp_header *h; skb_push(skb,sizeof(struct ppp_header)); h=(struct ppp_header *)skb->data; if(sp->pp_flags&PP_CISCO) { h->address = CISCO_UNICAST; h->control = 0; } else { h->address = PPP_ALLSTATIONS; h->control = PPP_UI; } if(sp->pp_flags & PP_CISCO) { h->protocol = htons(type); } else switch(type) { case ETH_P_IP: h->protocol = htons(PPP_IP); break; case ETH_P_IPX: h->protocol = htons(PPP_IPX); break; } return sizeof(struct ppp_header); } static int sppp_rebuild_header(struct sk_buff *skb) { return 0; } /* * Send keepalive packets, every 10 seconds. */ static void sppp_keepalive (unsigned long dummy) { struct sppp *sp; unsigned long flags; spin_lock_irqsave(&spppq_lock, flags); for (sp=spppq; sp; sp=sp->pp_next) { struct net_device *dev = sp->pp_if; /* Keepalive mode disabled or channel down? */ if (! (sp->pp_flags & PP_KEEPALIVE) || ! (dev->flags & IFF_UP)) continue; /* No keepalive in PPP mode if LCP not opened yet. */ if (! (sp->pp_flags & PP_CISCO) && sp->lcp.state != LCP_STATE_OPENED) continue; if (sp->pp_alivecnt == MAXALIVECNT) { /* No keepalive packets got. Stop the interface. */ printk (KERN_WARNING "%s: protocol down\n", dev->name); if_down (dev); if (! (sp->pp_flags & PP_CISCO)) { /* Shut down the PPP link. */ sp->lcp.magic = jiffies; sp->lcp.state = LCP_STATE_CLOSED; sp->ipcp.state = IPCP_STATE_CLOSED; sppp_clear_timeout (sp); /* Initiate negotiation. */ sppp_lcp_open (sp); } } if (sp->pp_alivecnt <= MAXALIVECNT) ++sp->pp_alivecnt; if (sp->pp_flags & PP_CISCO) sppp_cisco_send (sp, CISCO_KEEPALIVE_REQ, ++sp->pp_seq, sp->pp_rseq); else if (sp->lcp.state == LCP_STATE_OPENED) { long nmagic = htonl (sp->lcp.magic); sp->lcp.echoid = ++sp->pp_seq; sppp_cp_send (sp, PPP_LCP, LCP_ECHO_REQ, sp->lcp.echoid, 4, &nmagic); } } spin_unlock_irqrestore(&spppq_lock, flags); sppp_keepalive_timer.expires=jiffies+10*HZ; add_timer(&sppp_keepalive_timer); } /* * Handle incoming PPP Link Control Protocol packets. */ static void sppp_lcp_input (struct sppp *sp, struct sk_buff *skb) { struct lcp_header *h; struct net_device *dev = sp->pp_if; int len = skb->len; u8 *p, opt[6]; u32 rmagic; if (len < 4) { if (sp->pp_flags & PP_DEBUG) printk (KERN_WARNING "%s: invalid lcp packet length: %d bytes\n", dev->name, len); return; } h = (struct lcp_header *)skb->data; skb_pull(skb,sizeof(struct lcp_header *)); if (sp->pp_flags & PP_DEBUG) { char state = '?'; switch (sp->lcp.state) { case LCP_STATE_CLOSED: state = 'C'; break; case LCP_STATE_ACK_RCVD: state = 'R'; break; case LCP_STATE_ACK_SENT: state = 'S'; break; case LCP_STATE_OPENED: state = 'O'; break; } printk (KERN_WARNING "%s: lcp input(%c): %d bytes <%s id=%xh len=%xh", dev->name, state, len, sppp_lcp_type_name (h->type), h->ident, ntohs (h->len)); if (len > 4) sppp_print_bytes ((u8*) (h+1), len-4); printk (">\n"); } if (len > ntohs (h->len)) len = ntohs (h->len); switch (h->type) { default: /* Unknown packet type -- send Code-Reject packet. */ sppp_cp_send (sp, PPP_LCP, LCP_CODE_REJ, ++sp->pp_seq, skb->len, h); break; case LCP_CONF_REQ: if (len < 4) { if (sp->pp_flags & PP_DEBUG) printk (KERN_DEBUG"%s: invalid lcp configure request packet length: %d bytes\n", dev->name, len); break; } if (len>4 && !sppp_lcp_conf_parse_options (sp, h, len, &rmagic)) goto badreq; if (rmagic == sp->lcp.magic) { /* Local and remote magics equal -- loopback? */ if (sp->pp_loopcnt >= MAXALIVECNT*5) { printk (KERN_WARNING "%s: loopback\n", dev->name); sp->pp_loopcnt = 0; if (dev->flags & IFF_UP) { if_down (dev); } } else if (sp->pp_flags & PP_DEBUG) printk (KERN_DEBUG "%s: conf req: magic glitch\n", dev->name); ++sp->pp_loopcnt; /* MUST send Conf-Nack packet. */ rmagic = ~sp->lcp.magic; opt[0] = LCP_OPT_MAGIC; opt[1] = sizeof (opt); opt[2] = rmagic >> 24; opt[3] = rmagic >> 16; opt[4] = rmagic >> 8; opt[5] = rmagic; sppp_cp_send (sp, PPP_LCP, LCP_CONF_NAK, h->ident, sizeof (opt), &opt); badreq: switch (sp->lcp.state) { case LCP_STATE_OPENED: /* Initiate renegotiation. */ sppp_lcp_open (sp); /* fall through... */ case LCP_STATE_ACK_SENT: /* Go to closed state. */ sp->lcp.state = LCP_STATE_CLOSED; sp->ipcp.state = IPCP_STATE_CLOSED; } break; } /* Send Configure-Ack packet. */ sp->pp_loopcnt = 0; if (sp->lcp.state != LCP_STATE_OPENED) { sppp_cp_send (sp, PPP_LCP, LCP_CONF_ACK, h->ident, len-4, h+1); } /* Change the state. */ switch (sp->lcp.state) { case LCP_STATE_CLOSED: sp->lcp.state = LCP_STATE_ACK_SENT; break; case LCP_STATE_ACK_RCVD: sp->lcp.state = LCP_STATE_OPENED; sppp_ipcp_open (sp); break; case LCP_STATE_OPENED: /* Remote magic changed -- close session. */ sp->lcp.state = LCP_STATE_CLOSED; sp->ipcp.state = IPCP_STATE_CLOSED; /* Initiate renegotiation. */ sppp_lcp_open (sp); /* Send ACK after our REQ in attempt to break loop */ sppp_cp_send (sp, PPP_LCP, LCP_CONF_ACK, h->ident, len-4, h+1); sp->lcp.state = LCP_STATE_ACK_SENT; break; } break; case LCP_CONF_ACK: if (h->ident != sp->lcp.confid) break; sppp_clear_timeout (sp); if ((sp->pp_link_state != SPPP_LINK_UP) && (dev->flags & IFF_UP)) { /* Coming out of loopback mode. */ sp->pp_link_state=SPPP_LINK_UP; printk (KERN_INFO "%s: protocol up\n", dev->name); } switch (sp->lcp.state) { case LCP_STATE_CLOSED: sp->lcp.state = LCP_STATE_ACK_RCVD; sppp_set_timeout (sp, 5); break; case LCP_STATE_ACK_SENT: sp->lcp.state = LCP_STATE_OPENED; sppp_ipcp_open (sp); break; } break; case LCP_CONF_NAK: if (h->ident != sp->lcp.confid) break; p = (u8*) (h+1); if (len>=10 && p[0] == LCP_OPT_MAGIC && p[1] >= 4) { rmagic = (u32)p[2] << 24 | (u32)p[3] << 16 | p[4] << 8 | p[5]; if (rmagic == ~sp->lcp.magic) { int newmagic; if (sp->pp_flags & PP_DEBUG) printk (KERN_DEBUG "%s: conf nak: magic glitch\n", dev->name); get_random_bytes(&newmagic, sizeof(newmagic)); sp->lcp.magic += newmagic; } else sp->lcp.magic = rmagic; } if (sp->lcp.state != LCP_STATE_ACK_SENT) { /* Go to closed state. */ sp->lcp.state = LCP_STATE_CLOSED; sp->ipcp.state = IPCP_STATE_CLOSED; } /* The link will be renegotiated after timeout, * to avoid endless req-nack loop. */ sppp_clear_timeout (sp); sppp_set_timeout (sp, 2); break; case LCP_CONF_REJ: if (h->ident != sp->lcp.confid) break; sppp_clear_timeout (sp); /* Initiate renegotiation. */ sppp_lcp_open (sp); if (sp->lcp.state != LCP_STATE_ACK_SENT) { /* Go to closed state. */ sp->lcp.state = LCP_STATE_CLOSED; sp->ipcp.state = IPCP_STATE_CLOSED; } break; case LCP_TERM_REQ: sppp_clear_timeout (sp); /* Send Terminate-Ack packet. */ sppp_cp_send (sp, PPP_LCP, LCP_TERM_ACK, h->ident, 0, 0); /* Go to closed state. */ sp->lcp.state = LCP_STATE_CLOSED; sp->ipcp.state = IPCP_STATE_CLOSED; /* Initiate renegotiation. */ sppp_lcp_open (sp); break; case LCP_TERM_ACK: case LCP_CODE_REJ: case LCP_PROTO_REJ: /* Ignore for now. */ break; case LCP_DISC_REQ: /* Discard the packet. */ break; case LCP_ECHO_REQ: if (sp->lcp.state != LCP_STATE_OPENED) break; if (len < 8) { if (sp->pp_flags & PP_DEBUG) printk (KERN_WARNING "%s: invalid lcp echo request packet length: %d bytes\n", dev->name, len); break; } if (ntohl (*(long*)(h+1)) == sp->lcp.magic) { /* Line loopback mode detected. */ printk (KERN_WARNING "%s: loopback\n", dev->name); if_down (dev); /* Shut down the PPP link. */ sp->lcp.state = LCP_STATE_CLOSED; sp->ipcp.state = IPCP_STATE_CLOSED; sppp_clear_timeout (sp); /* Initiate negotiation. */ sppp_lcp_open (sp); break; } *(long*)(h+1) = htonl (sp->lcp.magic); sppp_cp_send (sp, PPP_LCP, LCP_ECHO_REPLY, h->ident, len-4, h+1); break; case LCP_ECHO_REPLY: if (h->ident != sp->lcp.echoid) break; if (len < 8) { if (sp->pp_flags & PP_DEBUG) printk (KERN_WARNING "%s: invalid lcp echo reply packet length: %d bytes\n", dev->name, len); break; } if (ntohl (*(long*)(h+1)) != sp->lcp.magic) sp->pp_alivecnt = 0; break; } } /* * Handle incoming Cisco keepalive protocol packets. */ static void sppp_cisco_input (struct sppp *sp, struct sk_buff *skb) { struct cisco_packet *h; struct net_device *dev = sp->pp_if; if (skb->len != CISCO_PACKET_LEN && skb->len != CISCO_BIG_PACKET_LEN) { if (sp->pp_flags & PP_DEBUG) printk (KERN_WARNING "%s: invalid cisco packet length: %d bytes\n", dev->name, skb->len); return; } h = (struct cisco_packet *)skb->data; skb_pull(skb, sizeof(struct cisco_packet*)); if (sp->pp_flags & PP_DEBUG) printk (KERN_WARNING "%s: cisco input: %d bytes <%xh %xh %xh %xh %xh-%xh>\n", dev->name, skb->len, ntohl (h->type), h->par1, h->par2, h->rel, h->time0, h->time1); switch (ntohl (h->type)) { default: if (sp->pp_flags & PP_DEBUG) printk (KERN_WARNING "%s: unknown cisco packet type: 0x%x\n", dev->name, ntohl (h->type)); break; case CISCO_ADDR_REPLY: /* Reply on address request, ignore */ break; case CISCO_KEEPALIVE_REQ: sp->pp_alivecnt = 0; sp->pp_rseq = ntohl (h->par1); if (sp->pp_seq == sp->pp_rseq) { /* Local and remote sequence numbers are equal. * Probably, the line is in loopback mode. */ int newseq; if (sp->pp_loopcnt >= MAXALIVECNT) { printk (KERN_WARNING "%s: loopback\n", dev->name); sp->pp_loopcnt = 0; if (dev->flags & IFF_UP) { if_down (dev); } } ++sp->pp_loopcnt; /* Generate new local sequence number */ get_random_bytes(&newseq, sizeof(newseq)); sp->pp_seq ^= newseq; break; } sp->pp_loopcnt = 0; if (sp->pp_link_state==SPPP_LINK_DOWN && (dev->flags & IFF_UP)) { sp->pp_link_state=SPPP_LINK_UP; printk (KERN_INFO "%s: protocol up\n", dev->name); } break; case CISCO_ADDR_REQ: /* Stolen from net/ipv4/devinet.c -- SIOCGIFADDR ioctl */ { struct in_device *in_dev; struct in_ifaddr *ifa; u32 addr = 0, mask = ~0; /* FIXME: is the mask correct? */ #ifdef CONFIG_INET if ((in_dev=in_dev_get(dev)) != NULL) { read_lock(&in_dev->lock); for (ifa=in_dev->ifa_list; ifa != NULL; ifa=ifa->ifa_next) { if (strcmp(dev->name, ifa->ifa_label) == 0) { addr = ifa->ifa_local; mask = ifa->ifa_mask; break; } } read_unlock(&in_dev->lock); in_dev_put(in_dev); } #endif /* I hope both addr and mask are in the net order */ sppp_cisco_send (sp, CISCO_ADDR_REPLY, addr, mask); break; } } } /* * Send PPP LCP packet. */ static void sppp_cp_send (struct sppp *sp, u16 proto, u8 type, u8 ident, u16 len, void *data) { struct ppp_header *h; struct lcp_header *lh; struct sk_buff *skb; struct net_device *dev = sp->pp_if; skb=alloc_skb(dev->hard_header_len+PPP_HEADER_LEN+LCP_HEADER_LEN+len, GFP_ATOMIC); if (skb==NULL) return; skb_reserve(skb,dev->hard_header_len); h = (struct ppp_header *)skb_put(skb, sizeof(struct ppp_header)); h->address = PPP_ALLSTATIONS; /* broadcast address */ h->control = PPP_UI; /* Unnumbered Info */ h->protocol = htons (proto); /* Link Control Protocol */ lh = (struct lcp_header *)skb_put(skb, sizeof(struct lcp_header)); lh->type = type; lh->ident = ident; lh->len = htons (LCP_HEADER_LEN + len); if (len) memcpy(skb_put(skb,len),data, len); if (sp->pp_flags & PP_DEBUG) { printk (KERN_WARNING "%s: %s output <%s id=%xh len=%xh", dev->name, proto==PPP_LCP ? "lcp" : "ipcp", proto==PPP_LCP ? sppp_lcp_type_name (lh->type) : sppp_ipcp_type_name (lh->type), lh->ident, ntohs (lh->len)); if (len) sppp_print_bytes ((u8*) (lh+1), len); printk (">\n"); } sp->obytes += skb->len; /* Control is high priority so it doesnt get queued behind data */ skb->priority=TC_PRIO_CONTROL; skb->dev = dev; dev_queue_xmit(skb); } /* * Send Cisco keepalive packet. */ static void sppp_cisco_send (struct sppp *sp, int type, long par1, long par2) { struct ppp_header *h; struct cisco_packet *ch; struct sk_buff *skb; struct net_device *dev = sp->pp_if; u32 t = jiffies * 1000/HZ; skb=alloc_skb(dev->hard_header_len+PPP_HEADER_LEN+CISCO_PACKET_LEN, GFP_ATOMIC); if(skb==NULL) return; skb_reserve(skb, dev->hard_header_len); h = (struct ppp_header *)skb_put (skb, sizeof(struct ppp_header)); h->address = CISCO_MULTICAST; h->control = 0; h->protocol = htons (CISCO_KEEPALIVE); ch = (struct cisco_packet*)skb_put(skb, CISCO_PACKET_LEN); ch->type = htonl (type); ch->par1 = htonl (par1); ch->par2 = htonl (par2); ch->rel = -1; ch->time0 = htons ((u16) (t >> 16)); ch->time1 = htons ((u16) t); if (sp->pp_flags & PP_DEBUG) printk (KERN_WARNING "%s: cisco output: <%xh %xh %xh %xh %xh-%xh>\n", dev->name, ntohl (ch->type), ch->par1, ch->par2, ch->rel, ch->time0, ch->time1); sp->obytes += skb->len; skb->priority=TC_PRIO_CONTROL; skb->dev = dev; dev_queue_xmit(skb); } /** * sppp_close - close down a synchronous PPP or Cisco HDLC link * @dev: The network device to drop the link of * * This drops the logical interface to the channel. It is not * done politely as we assume we will also be dropping DTR. Any * timeouts are killed. */ int sppp_close (struct net_device *dev) { struct sppp *sp = (struct sppp *)sppp_of(dev); sp->pp_link_state = SPPP_LINK_DOWN; sp->lcp.state = LCP_STATE_CLOSED; sp->ipcp.state = IPCP_STATE_CLOSED; sppp_clear_timeout (sp); return 0; } EXPORT_SYMBOL(sppp_close); /** * sppp_open - open a synchronous PPP or Cisco HDLC link * @dev: Network device to activate * * Close down any existing synchronous session and commence * from scratch. In the PPP case this means negotiating LCP/IPCP * and friends, while for Cisco HDLC we simply need to start sending * keepalives */ int sppp_open (struct net_device *dev) { struct sppp *sp = (struct sppp *)sppp_of(dev); sppp_close(dev); if (!(sp->pp_flags & PP_CISCO)) { sppp_lcp_open (sp); } sp->pp_link_state = SPPP_LINK_DOWN; return 0; } EXPORT_SYMBOL(sppp_open); /** * sppp_reopen - notify of physical link loss * @dev: Device that lost the link * * This function informs the synchronous protocol code that * the underlying link died (for example a carrier drop on X.21) * * We increment the magic numbers to ensure that if the other end * failed to notice we will correctly start a new session. It happens * do to the nature of telco circuits is that you can lose carrier on * one endonly. * * Having done this we go back to negotiating. This function may * be called from an interrupt context. */ int sppp_reopen (struct net_device *dev) { struct sppp *sp = (struct sppp *)sppp_of(dev); sppp_close(dev); if (!(sp->pp_flags & PP_CISCO)) { sp->lcp.magic = jiffies; ++sp->pp_seq; sp->lcp.state = LCP_STATE_CLOSED; sp->ipcp.state = IPCP_STATE_CLOSED; /* Give it a moment for the line to settle then go */ sppp_set_timeout (sp, 1); } sp->pp_link_state=SPPP_LINK_DOWN; return 0; } EXPORT_SYMBOL(sppp_reopen); /** * sppp_change_mtu - Change the link MTU * @dev: Device to change MTU on * @new_mtu: New MTU * * Change the MTU on the link. This can only be called with * the link down. It returns an error if the link is up or * the mtu is out of range. */ int sppp_change_mtu(struct net_device *dev, int new_mtu) { if(new_mtu<128||new_mtu>PPP_MTU||(dev->flags&IFF_UP)) return -EINVAL; dev->mtu=new_mtu; return 0; } EXPORT_SYMBOL(sppp_change_mtu); /** * sppp_do_ioctl - Ioctl handler for ppp/hdlc * @dev: Device subject to ioctl * @ifr: Interface request block from the user * @cmd: Command that is being issued * * This function handles the ioctls that may be issued by the user * to control the settings of a PPP/HDLC link. It does both busy * and security checks. This function is intended to be wrapped by * callers who wish to add additional ioctl calls of their own. */ int sppp_do_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) { struct sppp *sp = (struct sppp *)sppp_of(dev); if(dev->flags&IFF_UP) return -EBUSY; if(!capable(CAP_NET_ADMIN)) return -EPERM; switch(cmd) { case SPPPIOCCISCO: sp->pp_flags|=PP_CISCO; dev->type = ARPHRD_HDLC; break; case SPPPIOCPPP: sp->pp_flags&=~PP_CISCO; dev->type = ARPHRD_PPP; break; case SPPPIOCDEBUG: sp->pp_flags&=~PP_DEBUG; if(ifr->ifr_flags) sp->pp_flags|=PP_DEBUG; break; case SPPPIOCGFLAGS: if(copy_to_user(ifr->ifr_data, &sp->pp_flags, sizeof(sp->pp_flags))) return -EFAULT; break; case SPPPIOCSFLAGS: if(copy_from_user(&sp->pp_flags, ifr->ifr_data, sizeof(sp->pp_flags))) return -EFAULT; break; default: return -EINVAL; } return 0; } EXPORT_SYMBOL(sppp_do_ioctl); /** * sppp_attach - attach synchronous PPP/HDLC to a device * @pd: PPP device to initialise * * This initialises the PPP/HDLC support on an interface. At the * time of calling the dev element must point to the network device * that this interface is attached to. The interface should not yet * be registered. */ void sppp_attach(struct ppp_device *pd) { struct net_device *dev = pd->dev; struct sppp *sp = &pd->sppp; unsigned long flags; spin_lock_irqsave(&spppq_lock, flags); /* Initialize keepalive handler. */ if (! spppq) { init_timer(&sppp_keepalive_timer); sppp_keepalive_timer.expires=jiffies+10*HZ; sppp_keepalive_timer.function=sppp_keepalive; add_timer(&sppp_keepalive_timer); } /* Insert new entry into the keepalive list. */ sp->pp_next = spppq; spppq = sp; spin_unlock_irqrestore(&spppq_lock, flags); sp->pp_loopcnt = 0; sp->pp_alivecnt = 0; sp->pp_seq = 0; sp->pp_rseq = 0; sp->pp_flags = PP_KEEPALIVE|PP_CISCO|debug;/*PP_DEBUG;*/ sp->lcp.magic = 0; sp->lcp.state = LCP_STATE_CLOSED; sp->ipcp.state = IPCP_STATE_CLOSED; sp->pp_if = dev; /* * Device specific setup. All but interrupt handler and * hard_start_xmit. */ dev->hard_header = sppp_hard_header; dev->rebuild_header = sppp_rebuild_header; dev->tx_queue_len = 10; dev->type = ARPHRD_HDLC; dev->addr_len = 0; dev->hard_header_len = sizeof(struct ppp_header); dev->mtu = PPP_MTU; /* * These 4 are callers but MUST also call sppp_ functions */ dev->do_ioctl = sppp_do_ioctl; #if 0 dev->get_stats = NULL; /* Let the driver override these */ dev->open = sppp_open; dev->stop = sppp_close; #endif dev->change_mtu = sppp_change_mtu; dev->hard_header_cache = NULL; dev->header_cache_update = NULL; dev->flags = IFF_MULTICAST|IFF_POINTOPOINT|IFF_NOARP; } EXPORT_SYMBOL(sppp_attach); /** * sppp_detach - release PPP resources from a device * @dev: Network device to release * * Stop and free up any PPP/HDLC resources used by this * interface. This must be called before the device is * freed. */ void sppp_detach (struct net_device *dev) { struct sppp **q, *p, *sp = (struct sppp *)sppp_of(dev); unsigned long flags; spin_lock_irqsave(&spppq_lock, flags); /* Remove the entry from the keepalive list. */ for (q = &spppq; (p = *q); q = &p->pp_next) if (p == sp) { *q = p->pp_next; break; } /* Stop keepalive handler. */ if (! spppq) del_timer(&sppp_keepalive_timer); sppp_clear_timeout (sp); spin_unlock_irqrestore(&spppq_lock, flags); } EXPORT_SYMBOL(sppp_detach); /* * Analyze the LCP Configure-Request options list * for the presence of unknown options. * If the request contains unknown options, build and * send Configure-reject packet, containing only unknown options. */ static int sppp_lcp_conf_parse_options (struct sppp *sp, struct lcp_header *h, int len, u32 *magic) { u8 *buf, *r, *p; int rlen; len -= 4; buf = r = kmalloc (len, GFP_ATOMIC); if (! buf) return (0); p = (void*) (h+1); for (rlen=0; len>1 && p[1]; len-=p[1], p+=p[1]) { switch (*p) { case LCP_OPT_MAGIC: /* Magic number -- extract. */ if (len >= 6 && p[1] == 6) { *magic = (u32)p[2] << 24 | (u32)p[3] << 16 | p[4] << 8 | p[5]; continue; } break; case LCP_OPT_ASYNC_MAP: /* Async control character map -- check to be zero. */ if (len >= 6 && p[1] == 6 && ! p[2] && ! p[3] && ! p[4] && ! p[5]) continue; break; case LCP_OPT_MRU: /* Maximum receive unit -- always OK. */ continue; default: /* Others not supported. */ break; } /* Add the option to rejected list. */ memcpy(r, p, p[1]); r += p[1]; rlen += p[1]; } if (rlen) sppp_cp_send (sp, PPP_LCP, LCP_CONF_REJ, h->ident, rlen, buf); kfree(buf); return (rlen == 0); } static void sppp_ipcp_input (struct sppp *sp, struct sk_buff *skb) { struct lcp_header *h; struct net_device *dev = sp->pp_if; int len = skb->len; if (len < 4) { if (sp->pp_flags & PP_DEBUG) printk (KERN_WARNING "%s: invalid ipcp packet length: %d bytes\n", dev->name, len); return; } h = (struct lcp_header *)skb->data; skb_pull(skb,sizeof(struct lcp_header)); if (sp->pp_flags & PP_DEBUG) { printk (KERN_WARNING "%s: ipcp input: %d bytes <%s id=%xh len=%xh", dev->name, len, sppp_ipcp_type_name (h->type), h->ident, ntohs (h->len)); if (len > 4) sppp_print_bytes ((u8*) (h+1), len-4); printk (">\n"); } if (len > ntohs (h->len)) len = ntohs (h->len); switch (h->type) { default: /* Unknown packet type -- send Code-Reject packet. */ sppp_cp_send (sp, PPP_IPCP, IPCP_CODE_REJ, ++sp->pp_seq, len, h); break; case IPCP_CONF_REQ: if (len < 4) { if (sp->pp_flags & PP_DEBUG) printk (KERN_WARNING "%s: invalid ipcp configure request packet length: %d bytes\n", dev->name, len); return; } if (len > 4) { sppp_cp_send (sp, PPP_IPCP, LCP_CONF_REJ, h->ident, len-4, h+1); switch (sp->ipcp.state) { case IPCP_STATE_OPENED: /* Initiate renegotiation. */ sppp_ipcp_open (sp); /* fall through... */ case IPCP_STATE_ACK_SENT: /* Go to closed state. */ sp->ipcp.state = IPCP_STATE_CLOSED; } } else { /* Send Configure-Ack packet. */ sppp_cp_send (sp, PPP_IPCP, IPCP_CONF_ACK, h->ident, 0, 0); /* Change the state. */ if (sp->ipcp.state == IPCP_STATE_ACK_RCVD) sp->ipcp.state = IPCP_STATE_OPENED; else sp->ipcp.state = IPCP_STATE_ACK_SENT; } break; case IPCP_CONF_ACK: if (h->ident != sp->ipcp.confid) break; sppp_clear_timeout (sp); switch (sp->ipcp.state) { case IPCP_STATE_CLOSED: sp->ipcp.state = IPCP_STATE_ACK_RCVD; sppp_set_timeout (sp, 5); break; case IPCP_STATE_ACK_SENT: sp->ipcp.state = IPCP_STATE_OPENED; break; } break; case IPCP_CONF_NAK: case IPCP_CONF_REJ: if (h->ident != sp->ipcp.confid) break; sppp_clear_timeout (sp); /* Initiate renegotiation. */ sppp_ipcp_open (sp); if (sp->ipcp.state != IPCP_STATE_ACK_SENT) /* Go to closed state. */ sp->ipcp.state = IPCP_STATE_CLOSED; break; case IPCP_TERM_REQ: /* Send Terminate-Ack packet. */ sppp_cp_send (sp, PPP_IPCP, IPCP_TERM_ACK, h->ident, 0, 0); /* Go to closed state. */ sp->ipcp.state = IPCP_STATE_CLOSED; /* Initiate renegotiation. */ sppp_ipcp_open (sp); break; case IPCP_TERM_ACK: /* Ignore for now. */ case IPCP_CODE_REJ: /* Ignore for now. */ break; } } static void sppp_lcp_open (struct sppp *sp) { char opt[6]; if (! sp->lcp.magic) sp->lcp.magic = jiffies; opt[0] = LCP_OPT_MAGIC; opt[1] = sizeof (opt); opt[2] = sp->lcp.magic >> 24; opt[3] = sp->lcp.magic >> 16; opt[4] = sp->lcp.magic >> 8; opt[5] = sp->lcp.magic; sp->lcp.confid = ++sp->pp_seq; sppp_cp_send (sp, PPP_LCP, LCP_CONF_REQ, sp->lcp.confid, sizeof (opt), &opt); sppp_set_timeout (sp, 2); } static void sppp_ipcp_open (struct sppp *sp) { sp->ipcp.confid = ++sp->pp_seq; sppp_cp_send (sp, PPP_IPCP, IPCP_CONF_REQ, sp->ipcp.confid, 0, 0); sppp_set_timeout (sp, 2); } /* * Process PPP control protocol timeouts. */ static void sppp_cp_timeout (unsigned long arg) { struct sppp *sp = (struct sppp*) arg; unsigned long flags; save_flags(flags); cli(); sp->pp_flags &= ~PP_TIMO; if (! (sp->pp_if->flags & IFF_UP) || (sp->pp_flags & PP_CISCO)) { restore_flags(flags); return; } switch (sp->lcp.state) { case LCP_STATE_CLOSED: /* No ACK for Configure-Request, retry. */ sppp_lcp_open (sp); break; case LCP_STATE_ACK_RCVD: /* ACK got, but no Configure-Request for peer, retry. */ sppp_lcp_open (sp); sp->lcp.state = LCP_STATE_CLOSED; break; case LCP_STATE_ACK_SENT: /* ACK sent but no ACK for Configure-Request, retry. */ sppp_lcp_open (sp); break; case LCP_STATE_OPENED: /* LCP is already OK, try IPCP. */ switch (sp->ipcp.state) { case IPCP_STATE_CLOSED: /* No ACK for Configure-Request, retry. */ sppp_ipcp_open (sp); break; case IPCP_STATE_ACK_RCVD: /* ACK got, but no Configure-Request for peer, retry. */ sppp_ipcp_open (sp); sp->ipcp.state = IPCP_STATE_CLOSED; break; case IPCP_STATE_ACK_SENT: /* ACK sent but no ACK for Configure-Request, retry. */ sppp_ipcp_open (sp); break; case IPCP_STATE_OPENED: /* IPCP is OK. */ break; } break; } restore_flags(flags); } static char *sppp_lcp_type_name (u8 type) { static char buf [8]; switch (type) { case LCP_CONF_REQ: return ("conf-req"); case LCP_CONF_ACK: return ("conf-ack"); case LCP_CONF_NAK: return ("conf-nack"); case LCP_CONF_REJ: return ("conf-rej"); case LCP_TERM_REQ: return ("term-req"); case LCP_TERM_ACK: return ("term-ack"); case LCP_CODE_REJ: return ("code-rej"); case LCP_PROTO_REJ: return ("proto-rej"); case LCP_ECHO_REQ: return ("echo-req"); case LCP_ECHO_REPLY: return ("echo-reply"); case LCP_DISC_REQ: return ("discard-req"); } sprintf (buf, "%xh", type); return (buf); } static char *sppp_ipcp_type_name (u8 type) { static char buf [8]; switch (type) { case IPCP_CONF_REQ: return ("conf-req"); case IPCP_CONF_ACK: return ("conf-ack"); case IPCP_CONF_NAK: return ("conf-nack"); case IPCP_CONF_REJ: return ("conf-rej"); case IPCP_TERM_REQ: return ("term-req"); case IPCP_TERM_ACK: return ("term-ack"); case IPCP_CODE_REJ: return ("code-rej"); } sprintf (buf, "%xh", type); return (buf); } static void sppp_print_bytes (u_char *p, u16 len) { printk (" %x", *p++); while (--len > 0) printk ("-%x", *p++); } /** * sppp_rcv - receive and process a WAN PPP frame * @skb: The buffer to process * @dev: The device it arrived on * @p: Unused * * Protocol glue. This drives the deferred processing mode the poorer * cards use. This can be called directly by cards that do not have * timing constraints but is normally called from the network layer * after interrupt servicing to process frames queued via netif_rx. */ static int sppp_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *p) { sppp_input(dev,skb); return 0; } struct packet_type sppp_packet_type = { type: __constant_htons(ETH_P_WAN_PPP), func: sppp_rcv, }; static char banner[] __initdata = KERN_INFO "Cronyx Ltd, Synchronous PPP and CISCO HDLC (c) 1994\n" KERN_INFO "Linux port (c) 1998 Building Number Three Ltd & " "Jan \"Yenya\" Kasprzak.\n"; static int __init sync_ppp_init(void) { if(debug) debug=PP_DEBUG; printk(banner); dev_add_pack(&sppp_packet_type); return 0; } static void __exit sync_ppp_cleanup(void) { dev_remove_pack(&sppp_packet_type); } module_init(sync_ppp_init); module_exit(sync_ppp_cleanup); MODULE_PARM(debug,"1i"); MODULE_LICENSE("GPL");