From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- drivers/net/slip/Kconfig | 81 +++ drivers/net/slip/Makefile | 7 + drivers/net/slip/slhc.c | 780 ++++++++++++++++++++++++ drivers/net/slip/slip.c | 1442 +++++++++++++++++++++++++++++++++++++++++++++ drivers/net/slip/slip.h | 105 ++++ 5 files changed, 2415 insertions(+) create mode 100644 drivers/net/slip/Kconfig create mode 100644 drivers/net/slip/Makefile create mode 100644 drivers/net/slip/slhc.c create mode 100644 drivers/net/slip/slip.c create mode 100644 drivers/net/slip/slip.h (limited to 'drivers/net/slip') diff --git a/drivers/net/slip/Kconfig b/drivers/net/slip/Kconfig new file mode 100644 index 000000000..ea68fc15c --- /dev/null +++ b/drivers/net/slip/Kconfig @@ -0,0 +1,81 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# SLIP network device configuration +# + +config SLIP + tristate "SLIP (serial line) support" + depends on TTY + help + Say Y if you intend to use SLIP or CSLIP (compressed SLIP) to + connect to your Internet service provider or to connect to some + other local Unix box or if you want to configure your Linux box as a + Slip/CSlip server for other people to dial in. SLIP (Serial Line + Internet Protocol) is a protocol used to send Internet traffic over + serial connections such as telephone lines or null modem cables; + nowadays, the protocol PPP is more commonly used for this same + purpose. + + Normally, your access provider has to support SLIP in order for you + to be able to use it, but there is now a SLIP emulator called SLiRP + around (available from + ) which + allows you to use SLIP over a regular dial up shell connection. If + you plan to use SLiRP, make sure to say Y to CSLIP, below. The + NET-3-HOWTO, available from + , explains how to + configure SLIP. Note that you don't need this option if you just + want to run term (term is a program which gives you almost full + Internet connectivity if you have a regular dial up shell account on + some Internet connected Unix computer. Read + ). SLIP + support will enlarge your kernel by about 4 KB. If unsure, say N. + + To compile this driver as a module, choose M here. The module + will be called slip. + +config SLHC + tristate + help + This option enables Van Jacobsen serial line header compression + routines. + +if SLIP + +config SLIP_COMPRESSED + bool "CSLIP compressed headers" + depends on SLIP + select SLHC + help + This protocol is faster than SLIP because it uses compression on the + TCP/IP headers (not on the data itself), but it has to be supported + on both ends. Ask your access provider if you are not sure and + answer Y, just in case. You will still be able to use plain SLIP. If + you plan to use SLiRP, the SLIP emulator (available from + ) which + allows you to use SLIP over a regular dial up shell connection, you + definitely want to say Y here. The NET-3-HOWTO, available from + , explains how to configure + CSLIP. This won't enlarge your kernel. + +config SLIP_SMART + bool "Keepalive and linefill" + depends on SLIP + help + Adds additional capabilities to the SLIP driver to support the + RELCOM line fill and keepalive monitoring. Ideal on poor quality + analogue lines. + +config SLIP_MODE_SLIP6 + bool "Six bit SLIP encapsulation" + depends on SLIP + help + Just occasionally you may need to run IP over hostile serial + networks that don't pass all control characters or are only seven + bit. Saying Y here adds an extra mode you can use with SLIP: + "slip6". In this mode, SLIP will only send normal ASCII symbols over + the serial device. Naturally, this has to be supported at the other + end of the link as well. It's good enough, for example, to run IP + over the async ports of a Camtec JNT Pad. If unsure, say N. + +endif # SLIP diff --git a/drivers/net/slip/Makefile b/drivers/net/slip/Makefile new file mode 100644 index 000000000..668c1afb3 --- /dev/null +++ b/drivers/net/slip/Makefile @@ -0,0 +1,7 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Makefile for the SLIP network device drivers. +# + +obj-$(CONFIG_SLIP) += slip.o +obj-$(CONFIG_SLHC) += slhc.o diff --git a/drivers/net/slip/slhc.c b/drivers/net/slip/slhc.c new file mode 100644 index 000000000..1a9b27d5e --- /dev/null +++ b/drivers/net/slip/slhc.c @@ -0,0 +1,780 @@ +/* + * Routines to compress and uncompress tcp packets (for transmission + * over low speed serial lines). + * + * Copyright (c) 1989 Regents of the University of California. + * 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 University of California, Berkeley. 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. + * + * Van Jacobson (van@helios.ee.lbl.gov), Dec 31, 1989: + * - Initial distribution. + * + * + * modified for KA9Q Internet Software Package by + * Katie Stevens (dkstevens@ucdavis.edu) + * University of California, Davis + * Computing Services + * - 01-31-90 initial adaptation (from 1.19) + * PPP.05 02-15-90 [ks] + * PPP.08 05-02-90 [ks] use PPP protocol field to signal compression + * PPP.15 09-90 [ks] improve mbuf handling + * PPP.16 11-02 [karn] substantially rewritten to use NOS facilities + * + * - Feb 1991 Bill_Simpson@um.cc.umich.edu + * variable number of conversation slots + * allow zero or one slots + * separate routines + * status display + * - Jul 1994 Dmitry Gorodchanin + * Fixes for memory leaks. + * - Oct 1994 Dmitry Gorodchanin + * Modularization. + * - Jan 1995 Bjorn Ekwall + * Use ip_fast_csum from ip.h + * - July 1995 Christos A. Polyzols + * Spotted bug in tcp option checking + * + * + * This module is a difficult issue. It's clearly inet code but it's also clearly + * driver code belonging close to PPP and SLIP + */ + +#include +#include +#include +#include +#include +#include +#include + +#ifdef CONFIG_INET +/* Entire module is for IP only */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static unsigned char *encode(unsigned char *cp, unsigned short n); +static long decode(unsigned char **cpp, const unsigned char *end); +static unsigned char * put16(unsigned char *cp, unsigned short x); +static long pull16(unsigned char **cpp, const unsigned char *end); + +/* Allocate compression data structure + * slots must be in range 0 to 255 (zero meaning no compression) + * Returns pointer to structure or ERR_PTR() on error. + */ +struct slcompress * +slhc_init(int rslots, int tslots) +{ + short i; + struct cstate *ts; + struct slcompress *comp; + + if (rslots < 0 || rslots > 255 || tslots < 0 || tslots > 255) + return ERR_PTR(-EINVAL); + + comp = kzalloc_obj(struct slcompress); + if (! comp) + goto out_fail; + + if (rslots > 0) { + size_t rsize = rslots * sizeof(struct cstate); + comp->rstate = kzalloc(rsize, GFP_KERNEL); + if (! comp->rstate) + goto out_free; + comp->rslot_limit = rslots - 1; + } + + if (tslots > 0) { + size_t tsize = tslots * sizeof(struct cstate); + comp->tstate = kzalloc(tsize, GFP_KERNEL); + if (! comp->tstate) + goto out_free2; + comp->tslot_limit = tslots - 1; + } + + comp->xmit_oldest = 0; + comp->xmit_current = 255; + comp->recv_current = 255; + /* + * don't accept any packets with implicit index until we get + * one with an explicit index. Otherwise the uncompress code + * will try to use connection 255, which is almost certainly + * out of range + */ + comp->flags |= SLF_TOSS; + + if ( tslots > 0 ) { + ts = comp->tstate; + for(i = comp->tslot_limit; i > 0; --i){ + ts[i].cs_this = i; + ts[i].next = &(ts[i - 1]); + } + ts[0].next = &(ts[comp->tslot_limit]); + ts[0].cs_this = 0; + } + return comp; + +out_free2: + kfree(comp->rstate); +out_free: + kfree(comp); +out_fail: + return ERR_PTR(-ENOMEM); +} + + +/* Free a compression data structure */ +void +slhc_free(struct slcompress *comp) +{ + if ( IS_ERR_OR_NULL(comp) ) + return; + + if ( comp->tstate != NULLSLSTATE ) + kfree( comp->tstate ); + + if ( comp->rstate != NULLSLSTATE ) + kfree( comp->rstate ); + + kfree( comp ); +} + + +/* Put a short in host order into a char array in network order */ +static inline unsigned char * +put16(unsigned char *cp, unsigned short x) +{ + *cp++ = x >> 8; + *cp++ = x; + + return cp; +} + + +/* Encode a number */ +static unsigned char * +encode(unsigned char *cp, unsigned short n) +{ + if(n >= 256 || n == 0){ + *cp++ = 0; + cp = put16(cp,n); + } else { + *cp++ = n; + } + return cp; +} + +/* Pull a 16-bit integer in host order from buffer in network byte order. + * Returns -1 if the buffer is exhausted, otherwise the 16-bit value. + */ +static long +pull16(unsigned char **cpp, const unsigned char *end) +{ + long rval; + + if (*cpp + 2 > end) + return -1; + rval = *(*cpp)++; + rval <<= 8; + rval |= *(*cpp)++; + return rval; +} + +/* Decode a number. Returns -1 if the buffer is exhausted. */ +static long +decode(unsigned char **cpp, const unsigned char *end) +{ + int x; + + if (*cpp >= end) + return -1; + x = *(*cpp)++; + if (x == 0) + return pull16(cpp, end); + return x & 0xff; +} + +/* + * icp and isize are the original packet. + * ocp is a place to put a copy if necessary. + * cpp is initially a pointer to icp. If the copy is used, + * change it to ocp. + */ + +int +slhc_compress(struct slcompress *comp, unsigned char *icp, int isize, + unsigned char *ocp, unsigned char **cpp, int compress_cid) +{ + struct cstate *ocs = &(comp->tstate[comp->xmit_oldest]); + struct cstate *lcs = ocs; + struct cstate *cs = lcs->next; + unsigned long deltaS, deltaA; + short changes = 0; + int nlen, hlen; + unsigned char new_seq[16]; + unsigned char *cp = new_seq; + struct iphdr *ip; + struct tcphdr *th, *oth; + __sum16 csum; + + + /* + * Don't play with runt packets. + */ + + if(isizeversion != 4 || ip->ihl < 5) + return isize; + + /* Bail if this packet isn't TCP, or is an IP fragment */ + if (ip->protocol != IPPROTO_TCP || (ntohs(ip->frag_off) & 0x3fff)) { + /* Send as regular IP */ + if(ip->protocol != IPPROTO_TCP) + comp->sls_o_nontcp++; + else + comp->sls_o_tcp++; + return isize; + } + nlen = ip->ihl * 4; + if (isize < nlen + sizeof(*th)) + return isize; + + th = (struct tcphdr *)(icp + nlen); + if (th->doff < sizeof(struct tcphdr) / 4) + return isize; + hlen = nlen + th->doff * 4; + + /* Bail if the TCP packet isn't `compressible' (i.e., ACK isn't set or + * some other control bit is set). Also uncompressible if + * it's a runt. + */ + if(hlen > isize || th->syn || th->fin || th->rst || + ! (th->ack)){ + /* TCP connection stuff; send as regular IP */ + comp->sls_o_tcp++; + return isize; + } + /* + * Packet is compressible -- we're going to send either a + * COMPRESSED_TCP or UNCOMPRESSED_TCP packet. Either way, + * we need to locate (or create) the connection state. + * + * States are kept in a circularly linked list with + * xmit_oldest pointing to the end of the list. The + * list is kept in lru order by moving a state to the + * head of the list whenever it is referenced. Since + * the list is short and, empirically, the connection + * we want is almost always near the front, we locate + * states via linear search. If we don't find a state + * for the datagram, the oldest state is (re-)used. + */ + for ( ; ; ) { + if( ip->saddr == cs->cs_ip.saddr + && ip->daddr == cs->cs_ip.daddr + && th->source == cs->cs_tcp.source + && th->dest == cs->cs_tcp.dest) + goto found; + + /* if current equal oldest, at end of list */ + if ( cs == ocs ) + break; + lcs = cs; + cs = cs->next; + comp->sls_o_searches++; + } + /* + * Didn't find it -- re-use oldest cstate. Send an + * uncompressed packet that tells the other side what + * connection number we're using for this conversation. + * + * Note that since the state list is circular, the oldest + * state points to the newest and we only need to set + * xmit_oldest to update the lru linkage. + */ + comp->sls_o_misses++; + comp->xmit_oldest = lcs->cs_this; + goto uncompressed; + +found: + /* + * Found it -- move to the front on the connection list. + */ + if(lcs == ocs) { + /* found at most recently used */ + } else if (cs == ocs) { + /* found at least recently used */ + comp->xmit_oldest = lcs->cs_this; + } else { + /* more than 2 elements */ + lcs->next = cs->next; + cs->next = ocs->next; + ocs->next = cs; + } + + /* + * Make sure that only what we expect to change changed. + * Check the following: + * IP protocol version, header length & type of service. + * The "Don't fragment" bit. + * The time-to-live field. + * The TCP header length. + * IP options, if any. + * TCP options, if any. + * If any of these things are different between the previous & + * current datagram, we send the current datagram `uncompressed'. + */ + oth = &cs->cs_tcp; + + if(ip->version != cs->cs_ip.version || ip->ihl != cs->cs_ip.ihl + || ip->tos != cs->cs_ip.tos + || (ip->frag_off & htons(0x4000)) != (cs->cs_ip.frag_off & htons(0x4000)) + || ip->ttl != cs->cs_ip.ttl + || th->doff != cs->cs_tcp.doff + || (ip->ihl > 5 && memcmp(ip+1,cs->cs_ipopt,((ip->ihl)-5)*4) != 0) + || (th->doff > 5 && memcmp(th+1,cs->cs_tcpopt,((th->doff)-5)*4) != 0)){ + goto uncompressed; + } + + /* + * Figure out which of the changing fields changed. The + * receiver expects changes in the order: urgent, window, + * ack, seq (the order minimizes the number of temporaries + * needed in this section of code). + */ + if(th->urg){ + deltaS = ntohs(th->urg_ptr); + cp = encode(cp,deltaS); + changes |= NEW_U; + } else if(th->urg_ptr != oth->urg_ptr){ + /* argh! URG not set but urp changed -- a sensible + * implementation should never do this but RFC793 + * doesn't prohibit the change so we have to deal + * with it. */ + goto uncompressed; + } + if((deltaS = ntohs(th->window) - ntohs(oth->window)) != 0){ + cp = encode(cp,deltaS); + changes |= NEW_W; + } + if((deltaA = ntohl(th->ack_seq) - ntohl(oth->ack_seq)) != 0L){ + if(deltaA > 0x0000ffff) + goto uncompressed; + cp = encode(cp,deltaA); + changes |= NEW_A; + } + if((deltaS = ntohl(th->seq) - ntohl(oth->seq)) != 0L){ + if(deltaS > 0x0000ffff) + goto uncompressed; + cp = encode(cp,deltaS); + changes |= NEW_S; + } + + switch(changes){ + case 0: /* Nothing changed. If this packet contains data and the + * last one didn't, this is probably a data packet following + * an ack (normal on an interactive connection) and we send + * it compressed. Otherwise it's probably a retransmit, + * retransmitted ack or window probe. Send it uncompressed + * in case the other side missed the compressed version. + */ + if(ip->tot_len != cs->cs_ip.tot_len && + ntohs(cs->cs_ip.tot_len) == hlen) + break; + goto uncompressed; + case SPECIAL_I: + case SPECIAL_D: + /* actual changes match one of our special case encodings -- + * send packet uncompressed. + */ + goto uncompressed; + case NEW_S|NEW_A: + if(deltaS == deltaA && + deltaS == ntohs(cs->cs_ip.tot_len) - hlen){ + /* special case for echoed terminal traffic */ + changes = SPECIAL_I; + cp = new_seq; + } + break; + case NEW_S: + if(deltaS == ntohs(cs->cs_ip.tot_len) - hlen){ + /* special case for data xfer */ + changes = SPECIAL_D; + cp = new_seq; + } + break; + } + deltaS = ntohs(ip->id) - ntohs(cs->cs_ip.id); + if(deltaS != 1){ + cp = encode(cp,deltaS); + changes |= NEW_I; + } + if(th->psh) + changes |= TCP_PUSH_BIT; + /* Grab the cksum before we overwrite it below. Then update our + * state with this packet's header. + */ + csum = th->check; + memcpy(&cs->cs_ip,ip,20); + memcpy(&cs->cs_tcp,th,20); + /* We want to use the original packet as our compressed packet. + * (cp - new_seq) is the number of bytes we need for compressed + * sequence numbers. In addition we need one byte for the change + * mask, one for the connection id and two for the tcp checksum. + * So, (cp - new_seq) + 4 bytes of header are needed. + */ + deltaS = cp - new_seq; + if(compress_cid == 0 || comp->xmit_current != cs->cs_this){ + cp = ocp; + *cpp = ocp; + *cp++ = changes | NEW_C; + *cp++ = cs->cs_this; + comp->xmit_current = cs->cs_this; + } else { + cp = ocp; + *cpp = ocp; + *cp++ = changes; + } + *(__sum16 *)cp = csum; + cp += 2; +/* deltaS is now the size of the change section of the compressed header */ + memcpy(cp,new_seq,deltaS); /* Write list of deltas */ + memcpy(cp+deltaS,icp+hlen,isize-hlen); + comp->sls_o_compressed++; + ocp[0] |= SL_TYPE_COMPRESSED_TCP; + return isize - hlen + deltaS + (cp - ocp); + + /* Update connection state cs & send uncompressed packet (i.e., + * a regular ip/tcp packet but with the 'conversation id' we hope + * to use on future compressed packets in the protocol field). + */ +uncompressed: + memcpy(&cs->cs_ip,ip,20); + memcpy(&cs->cs_tcp,th,20); + if (ip->ihl > 5) + memcpy(cs->cs_ipopt, ip+1, ((ip->ihl) - 5) * 4); + if (th->doff > 5) + memcpy(cs->cs_tcpopt, th+1, ((th->doff) - 5) * 4); + comp->xmit_current = cs->cs_this; + comp->sls_o_uncompressed++; + memcpy(ocp, icp, isize); + *cpp = ocp; + ocp[9] = cs->cs_this; + ocp[0] |= SL_TYPE_UNCOMPRESSED_TCP; + return isize; +} + + +int +slhc_uncompress(struct slcompress *comp, unsigned char *icp, int isize) +{ + int changes; + long x; + struct tcphdr *thp; + struct iphdr *ip; + struct cstate *cs; + int len, hdrlen; + unsigned char *cp = icp; + const unsigned char *end = icp + isize; + + /* We've got a compressed packet; read the change byte */ + comp->sls_i_compressed++; + if(isize < 3){ + comp->sls_i_error++; + return 0; + } + if (!comp->rstate) + goto bad; + changes = *cp++; + if(changes & NEW_C){ + /* Make sure the state index is in range, then grab the state. + * If we have a good state index, clear the 'discard' flag. + */ + x = *cp++; /* Read conn index */ + if(x < 0 || x > comp->rslot_limit) + goto bad; + + /* Check if the cstate is initialized */ + if (!comp->rstate[x].initialized) + goto bad; + + comp->flags &=~ SLF_TOSS; + comp->recv_current = x; + } else { + /* this packet has an implicit state index. If we've + * had a line error since the last time we got an + * explicit state index, we have to toss the packet. */ + if(comp->flags & SLF_TOSS){ + comp->sls_i_tossed++; + return 0; + } + } + cs = &comp->rstate[comp->recv_current]; + thp = &cs->cs_tcp; + ip = &cs->cs_ip; + + if (cp + 2 > end) + goto bad; + thp->check = *(__sum16 *)cp; + cp += 2; + + thp->psh = (changes & TCP_PUSH_BIT) ? 1 : 0; +/* + * we can use the same number for the length of the saved header and + * the current one, because the packet wouldn't have been sent + * as compressed unless the options were the same as the previous one + */ + + hdrlen = ip->ihl * 4 + thp->doff * 4; + + switch(changes & SPECIALS_MASK){ + case SPECIAL_I: /* Echoed terminal traffic */ + { + short i; + i = ntohs(ip->tot_len) - hdrlen; + thp->ack_seq = htonl( ntohl(thp->ack_seq) + i); + thp->seq = htonl( ntohl(thp->seq) + i); + } + break; + + case SPECIAL_D: /* Unidirectional data */ + thp->seq = htonl( ntohl(thp->seq) + + ntohs(ip->tot_len) - hdrlen); + break; + + default: + if(changes & NEW_U){ + thp->urg = 1; + if((x = decode(&cp, end)) == -1) { + goto bad; + } + thp->urg_ptr = htons(x); + } else + thp->urg = 0; + if(changes & NEW_W){ + if((x = decode(&cp, end)) == -1) { + goto bad; + } + thp->window = htons( ntohs(thp->window) + x); + } + if(changes & NEW_A){ + if((x = decode(&cp, end)) == -1) { + goto bad; + } + thp->ack_seq = htonl( ntohl(thp->ack_seq) + x); + } + if(changes & NEW_S){ + if((x = decode(&cp, end)) == -1) { + goto bad; + } + thp->seq = htonl( ntohl(thp->seq) + x); + } + break; + } + if(changes & NEW_I){ + if((x = decode(&cp, end)) == -1) { + goto bad; + } + ip->id = htons (ntohs (ip->id) + x); + } else + ip->id = htons (ntohs (ip->id) + 1); + + /* + * At this point, cp points to the first byte of data in the + * packet. Put the reconstructed TCP and IP headers back on the + * packet. Recalculate IP checksum (but not TCP checksum). + */ + + len = isize - (cp - icp); + if (len < 0) + goto bad; + len += hdrlen; + ip->tot_len = htons(len); + ip->check = 0; + + memmove(icp + hdrlen, cp, len - hdrlen); + + cp = icp; + memcpy(cp, ip, 20); + cp += 20; + + if (ip->ihl > 5) { + memcpy(cp, cs->cs_ipopt, (ip->ihl - 5) * 4); + cp += (ip->ihl - 5) * 4; + } + + put_unaligned(ip_fast_csum(icp, ip->ihl), + &((struct iphdr *)icp)->check); + + memcpy(cp, thp, 20); + cp += 20; + + if (thp->doff > 5) { + memcpy(cp, cs->cs_tcpopt, ((thp->doff) - 5) * 4); + cp += ((thp->doff) - 5) * 4; + } + + return len; +bad: + comp->sls_i_error++; + return slhc_toss( comp ); +} + + +int +slhc_remember(struct slcompress *comp, unsigned char *icp, int isize) +{ + const struct tcphdr *th; + unsigned char index; + struct iphdr *iph; + struct cstate *cs; + unsigned int ihl; + + if (!comp->rstate) { + comp->sls_i_error++; + return slhc_toss(comp); + } + /* The packet is shorter than a legal IP header. + * Also make sure isize is positive. + */ + if (isize < (int)sizeof(struct iphdr)) { +runt: + comp->sls_i_runt++; + return slhc_toss(comp); + } + iph = (struct iphdr *)icp; + /* Peek at the IP header's IHL field to find its length */ + ihl = iph->ihl; + /* The IP header length field is too small, + * or packet is shorter than the IP header followed + * by minimal tcp header. + */ + if (ihl < 5 || isize < ihl * 4 + sizeof(struct tcphdr)) + goto runt; + + index = iph->protocol; + iph->protocol = IPPROTO_TCP; + + if (ip_fast_csum(icp, ihl)) { + /* Bad IP header checksum; discard */ + comp->sls_i_badcheck++; + return slhc_toss(comp); + } + if (index > comp->rslot_limit) { + comp->sls_i_error++; + return slhc_toss(comp); + } + th = (struct tcphdr *)(icp + ihl * 4); + if (th->doff < sizeof(struct tcphdr) / 4) + goto runt; + if (isize < ihl * 4 + th->doff * 4) + goto runt; + /* Update local state */ + cs = &comp->rstate[comp->recv_current = index]; + comp->flags &=~ SLF_TOSS; + memcpy(&cs->cs_ip, iph, sizeof(*iph)); + memcpy(&cs->cs_tcp, th, sizeof(*th)); + if (ihl > 5) + memcpy(cs->cs_ipopt, &iph[1], (ihl - 5) * 4); + if (th->doff > 5) + memcpy(cs->cs_tcpopt, &th[1], (th->doff - 5) * 4); + cs->cs_hsize = ihl*2 + th->doff*2; + cs->initialized = true; + /* Put headers back on packet + * Neither header checksum is recalculated + */ + comp->sls_i_uncompressed++; + return isize; +} + +int +slhc_toss(struct slcompress *comp) +{ + if ( comp == NULLSLCOMPR ) + return 0; + + comp->flags |= SLF_TOSS; + return 0; +} + +#else /* CONFIG_INET */ + +int +slhc_toss(struct slcompress *comp) +{ + printk(KERN_DEBUG "Called IP function on non IP-system: slhc_toss"); + return -EINVAL; +} +int +slhc_uncompress(struct slcompress *comp, unsigned char *icp, int isize) +{ + printk(KERN_DEBUG "Called IP function on non IP-system: slhc_uncompress"); + return -EINVAL; +} +int +slhc_compress(struct slcompress *comp, unsigned char *icp, int isize, + unsigned char *ocp, unsigned char **cpp, int compress_cid) +{ + printk(KERN_DEBUG "Called IP function on non IP-system: slhc_compress"); + return -EINVAL; +} + +int +slhc_remember(struct slcompress *comp, unsigned char *icp, int isize) +{ + printk(KERN_DEBUG "Called IP function on non IP-system: slhc_remember"); + return -EINVAL; +} + +void +slhc_free(struct slcompress *comp) +{ + printk(KERN_DEBUG "Called IP function on non IP-system: slhc_free"); +} +struct slcompress * +slhc_init(int rslots, int tslots) +{ + printk(KERN_DEBUG "Called IP function on non IP-system: slhc_init"); + return NULL; +} + +#endif /* CONFIG_INET */ + +/* VJ header compression */ +EXPORT_SYMBOL(slhc_init); +EXPORT_SYMBOL(slhc_free); +EXPORT_SYMBOL(slhc_remember); +EXPORT_SYMBOL(slhc_compress); +EXPORT_SYMBOL(slhc_uncompress); +EXPORT_SYMBOL(slhc_toss); + +MODULE_DESCRIPTION("Compression helpers for SLIP (serial line)"); +MODULE_LICENSE("Dual BSD/GPL"); diff --git a/drivers/net/slip/slip.c b/drivers/net/slip/slip.c new file mode 100644 index 000000000..fdd6f63fb --- /dev/null +++ b/drivers/net/slip/slip.c @@ -0,0 +1,1442 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * slip.c This module implements the SLIP protocol for kernel-based + * devices like TTY. It interfaces between a raw TTY, and the + * kernel's INET protocol layers. + * + * Version: @(#)slip.c 0.8.3 12/24/94 + * + * Authors: Laurence Culhane, + * Fred N. van Kempen, + * + * Fixes: + * Alan Cox : Sanity checks and avoid tx overruns. + * Has a new sl->mtu field. + * Alan Cox : Found cause of overrun. ifconfig sl0 + * mtu upwards. Driver now spots this + * and grows/shrinks its buffers(hack!). + * Memory leak if you run out of memory + * setting up a slip driver fixed. + * Matt Dillon : Printable slip (borrowed from NET2E) + * Pauline Middelink : Slip driver fixes. + * Alan Cox : Honours the old SL_COMPRESSED flag + * Alan Cox : KISS AX.25 and AXUI IP support + * Michael Riepe : Automatic CSLIP recognition added + * Charles Hedrick : CSLIP header length problem fix. + * Alan Cox : Corrected non-IP cases of the above. + * Alan Cox : Now uses hardware type as per FvK. + * Alan Cox : Default to 192.168.0.0 (RFC 1597) + * A.N.Kuznetsov : dev_tint() recursion fix. + * Dmitry Gorodchanin : SLIP memory leaks + * Dmitry Gorodchanin : Code cleanup. Reduce tty driver + * buffering from 4096 to 256 bytes. + * Improving SLIP response time. + * CONFIG_SLIP_MODE_SLIP6. + * ifconfig sl? up & down now works + * correctly. + * Modularization. + * Alan Cox : Oops - fix AX.25 buffer lengths + * Dmitry Gorodchanin : Even more cleanups. Preserve CSLIP + * statistics. Include CSLIP code only + * if it really needed. + * Alan Cox : Free slhc buffers in the right place. + * Alan Cox : Allow for digipeated IP over AX.25 + * Matti Aarnio : Dynamic SLIP devices, with ideas taken + * from Jim Freeman's + * dynamic PPP devices. We do NOT kfree() + * device entries, just reg./unreg. them + * as they are needed. We kfree() them + * at module cleanup. + * With MODULE-loading ``insmod'', user + * can issue parameter: slip_maxdev=1024 + * (Or how much he/she wants.. Default + * is 256) + * Stanislav Voronyi : Slip line checking, with ideas taken + * from multislip BSDI driver which was + * written by Igor Chechik, RELCOM Corp. + * Only algorithms have been ported to + * Linux SLIP driver. + * Vitaly E. Lavrov : Sane behaviour on tty hangup. + * Alexey Kuznetsov : Cleanup interfaces to tty & netdevice + * modules. + */ + +#define SL_CHECK_TRANSMIT +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "slip.h" +#ifdef CONFIG_INET +#include +#include +#include +#endif + +#define SLIP_VERSION "0.8.4-NET3.019-NEWTTY" + +static struct net_device **slip_devs; + +static int slip_maxdev = SL_NRUNIT; +module_param(slip_maxdev, int, 0); +MODULE_PARM_DESC(slip_maxdev, "Maximum number of slip devices"); + +static int slip_esc(unsigned char *p, unsigned char *d, int len); +static void slip_unesc(struct slip *sl, unsigned char c); +#ifdef CONFIG_SLIP_MODE_SLIP6 +static int slip_esc6(unsigned char *p, unsigned char *d, int len); +static void slip_unesc6(struct slip *sl, unsigned char c); +#endif +#ifdef CONFIG_SLIP_SMART +static void sl_keepalive(struct timer_list *t); +static void sl_outfill(struct timer_list *t); +static int sl_siocdevprivate(struct net_device *dev, struct ifreq *rq, void __user *data, int cmd); +#endif + +/******************************** +* Buffer administration routines: +* sl_alloc_bufs() +* sl_free_bufs() +* sl_realloc_bufs() +* +* NOTE: sl_realloc_bufs != sl_free_bufs + sl_alloc_bufs, because +* sl_realloc_bufs provides strong atomicity and reallocation +* on actively running device. +*********************************/ + +/* + Allocate channel buffers. + */ + +static int sl_alloc_bufs(struct slip *sl, int mtu) +{ + int err = -ENOBUFS; + unsigned long len; + char *rbuff = NULL; + char *xbuff = NULL; +#ifdef SL_INCLUDE_CSLIP + char *cbuff = NULL; + struct slcompress *slcomp = NULL; +#endif + + /* + * Allocate the SLIP frame buffers: + * + * rbuff Receive buffer. + * xbuff Transmit buffer. + * cbuff Temporary compression buffer. + */ + len = mtu * 2; + + /* + * allow for arrival of larger UDP packets, even if we say not to + * also fixes a bug in which SunOS sends 512-byte packets even with + * an MSS of 128 + */ + if (len < 576 * 2) + len = 576 * 2; + rbuff = kmalloc(len + 4, GFP_KERNEL); + if (rbuff == NULL) + goto err_exit; + xbuff = kmalloc(len + 4, GFP_KERNEL); + if (xbuff == NULL) + goto err_exit; +#ifdef SL_INCLUDE_CSLIP + cbuff = kmalloc(len + 4, GFP_KERNEL); + if (cbuff == NULL) + goto err_exit; + slcomp = slhc_init(16, 16); + if (IS_ERR(slcomp)) + goto err_exit; +#endif + spin_lock_bh(&sl->lock); + if (sl->tty == NULL) { + spin_unlock_bh(&sl->lock); + err = -ENODEV; + goto err_exit; + } + sl->mtu = mtu; + sl->buffsize = len; + sl->rcount = 0; + sl->xleft = 0; + rbuff = xchg(&sl->rbuff, rbuff); + xbuff = xchg(&sl->xbuff, xbuff); +#ifdef SL_INCLUDE_CSLIP + cbuff = xchg(&sl->cbuff, cbuff); + slcomp = xchg(&sl->slcomp, slcomp); +#endif +#ifdef CONFIG_SLIP_MODE_SLIP6 + sl->xdata = 0; + sl->xbits = 0; +#endif + spin_unlock_bh(&sl->lock); + err = 0; + + /* Cleanup */ +err_exit: +#ifdef SL_INCLUDE_CSLIP + kfree(cbuff); + slhc_free(slcomp); +#endif + kfree(xbuff); + kfree(rbuff); + return err; +} + +/* Free a SLIP channel buffers. */ +static void sl_free_bufs(struct slip *sl) +{ + /* Free all SLIP frame buffers. */ + kfree(xchg(&sl->rbuff, NULL)); + kfree(xchg(&sl->xbuff, NULL)); +#ifdef SL_INCLUDE_CSLIP + kfree(xchg(&sl->cbuff, NULL)); + slhc_free(xchg(&sl->slcomp, NULL)); +#endif +} + +/* + Reallocate slip channel buffers. + */ + +static int sl_realloc_bufs(struct slip *sl, int mtu) +{ + int err = 0; + struct net_device *dev = sl->dev; + unsigned char *xbuff, *rbuff; +#ifdef SL_INCLUDE_CSLIP + unsigned char *cbuff; +#endif + int len = mtu * 2; + +/* + * allow for arrival of larger UDP packets, even if we say not to + * also fixes a bug in which SunOS sends 512-byte packets even with + * an MSS of 128 + */ + if (len < 576 * 2) + len = 576 * 2; + + xbuff = kmalloc(len + 4, GFP_ATOMIC); + rbuff = kmalloc(len + 4, GFP_ATOMIC); +#ifdef SL_INCLUDE_CSLIP + cbuff = kmalloc(len + 4, GFP_ATOMIC); +#endif + + +#ifdef SL_INCLUDE_CSLIP + if (xbuff == NULL || rbuff == NULL || cbuff == NULL) { +#else + if (xbuff == NULL || rbuff == NULL) { +#endif + if (mtu > sl->mtu) { + printk(KERN_WARNING "%s: unable to grow slip buffers, MTU change cancelled.\n", + dev->name); + err = -ENOBUFS; + } + goto done; + } + spin_lock_bh(&sl->lock); + + err = -ENODEV; + if (sl->tty == NULL) + goto done_on_bh; + + xbuff = xchg(&sl->xbuff, xbuff); + rbuff = xchg(&sl->rbuff, rbuff); +#ifdef SL_INCLUDE_CSLIP + cbuff = xchg(&sl->cbuff, cbuff); +#endif + if (sl->xleft) { + if (sl->xleft <= len) { + memcpy(sl->xbuff, sl->xhead, sl->xleft); + } else { + sl->xleft = 0; + dev->stats.tx_dropped++; + } + } + sl->xhead = sl->xbuff; + + if (sl->rcount) { + if (sl->rcount <= len) { + memcpy(sl->rbuff, rbuff, sl->rcount); + } else { + sl->rcount = 0; + dev->stats.rx_over_errors++; + set_bit(SLF_ERROR, &sl->flags); + } + } + sl->mtu = mtu; + WRITE_ONCE(dev->mtu, mtu); + sl->buffsize = len; + err = 0; + +done_on_bh: + spin_unlock_bh(&sl->lock); + +done: + kfree(xbuff); + kfree(rbuff); +#ifdef SL_INCLUDE_CSLIP + kfree(cbuff); +#endif + return err; +} + + +/* Set the "sending" flag. This must be atomic hence the set_bit. */ +static inline void sl_lock(struct slip *sl) +{ + netif_stop_queue(sl->dev); +} + + +/* Clear the "sending" flag. This must be atomic, hence the ASM. */ +static inline void sl_unlock(struct slip *sl) +{ + netif_wake_queue(sl->dev); +} + +/* Send one completely decapsulated IP datagram to the IP layer. */ +static void sl_bump(struct slip *sl) +{ + struct net_device *dev = sl->dev; + struct sk_buff *skb; + int count; + + count = sl->rcount; +#ifdef SL_INCLUDE_CSLIP + if (sl->mode & (SL_MODE_ADAPTIVE | SL_MODE_CSLIP)) { + unsigned char c = sl->rbuff[0]; + if (c & SL_TYPE_COMPRESSED_TCP) { + /* ignore compressed packets when CSLIP is off */ + if (!(sl->mode & SL_MODE_CSLIP)) { + printk(KERN_WARNING "%s: compressed packet ignored\n", dev->name); + return; + } + /* make sure we've reserved enough space for uncompress + to use */ + if (count + 80 > sl->buffsize) { + dev->stats.rx_over_errors++; + return; + } + count = slhc_uncompress(sl->slcomp, sl->rbuff, count); + if (count <= 0) + return; + } else if (c >= SL_TYPE_UNCOMPRESSED_TCP) { + if (!(sl->mode & SL_MODE_CSLIP)) { + /* turn on header compression */ + sl->mode |= SL_MODE_CSLIP; + sl->mode &= ~SL_MODE_ADAPTIVE; + printk(KERN_INFO "%s: header compression turned on\n", dev->name); + } + sl->rbuff[0] &= 0x4f; + if (slhc_remember(sl->slcomp, sl->rbuff, count) <= 0) + return; + } + } +#endif /* SL_INCLUDE_CSLIP */ + + dev->stats.rx_bytes += count; + + skb = dev_alloc_skb(count); + if (skb == NULL) { + printk(KERN_WARNING "%s: memory squeeze, dropping packet.\n", dev->name); + dev->stats.rx_dropped++; + return; + } + skb->dev = dev; + skb_put_data(skb, sl->rbuff, count); + skb_reset_mac_header(skb); + skb->protocol = htons(ETH_P_IP); + netif_rx(skb); + dev->stats.rx_packets++; +} + +/* Encapsulate one IP datagram and stuff into a TTY queue. */ +static void sl_encaps(struct slip *sl, unsigned char *icp, int len) +{ + unsigned char *p; + int actual, count; + + if (len > sl->mtu) { /* Sigh, shouldn't occur BUT ... */ + printk(KERN_WARNING "%s: truncating oversized transmit packet!\n", sl->dev->name); + sl->dev->stats.tx_dropped++; + sl_unlock(sl); + return; + } + + p = icp; +#ifdef SL_INCLUDE_CSLIP + if (sl->mode & SL_MODE_CSLIP) + len = slhc_compress(sl->slcomp, p, len, sl->cbuff, &p, 1); +#endif +#ifdef CONFIG_SLIP_MODE_SLIP6 + if (sl->mode & SL_MODE_SLIP6) + count = slip_esc6(p, sl->xbuff, len); + else +#endif + count = slip_esc(p, sl->xbuff, len); + + /* Order of next two lines is *very* important. + * When we are sending a little amount of data, + * the transfer may be completed inside the ops->write() + * routine, because it's running with interrupts enabled. + * In this case we *never* got WRITE_WAKEUP event, + * if we did not request it before write operation. + * 14 Oct 1994 Dmitry Gorodchanin. + */ + set_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); + actual = sl->tty->ops->write(sl->tty, sl->xbuff, count); +#ifdef SL_CHECK_TRANSMIT + netif_trans_update(sl->dev); +#endif + sl->xleft = count - actual; + sl->xhead = sl->xbuff + actual; +#ifdef CONFIG_SLIP_SMART + /* VSV */ + clear_bit(SLF_OUTWAIT, &sl->flags); /* reset outfill flag */ +#endif +} + +/* Write out any remaining transmit buffer. Scheduled when tty is writable */ +static void slip_transmit(struct work_struct *work) +{ + struct slip *sl = container_of(work, struct slip, tx_work); + int actual; + + spin_lock_bh(&sl->lock); + /* First make sure we're connected. */ + if (!sl->tty || sl->magic != SLIP_MAGIC || !netif_running(sl->dev)) { + spin_unlock_bh(&sl->lock); + return; + } + + if (sl->xleft <= 0) { + /* Now serial buffer is almost free & we can start + * transmission of another packet */ + sl->dev->stats.tx_packets++; + clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); + spin_unlock_bh(&sl->lock); + sl_unlock(sl); + return; + } + + actual = sl->tty->ops->write(sl->tty, sl->xhead, sl->xleft); + sl->xleft -= actual; + sl->xhead += actual; + spin_unlock_bh(&sl->lock); +} + +/* + * Called by the driver when there's room for more data. + * Schedule the transmit. + */ +static void slip_write_wakeup(struct tty_struct *tty) +{ + struct slip *sl; + + rcu_read_lock(); + sl = rcu_dereference(tty->disc_data); + if (sl) + schedule_work(&sl->tx_work); + rcu_read_unlock(); +} + +static void sl_tx_timeout(struct net_device *dev, unsigned int txqueue) +{ + struct slip *sl = netdev_priv(dev); + + spin_lock(&sl->lock); + + if (netif_queue_stopped(dev)) { + if (!netif_running(dev) || !sl->tty) + goto out; + + /* May be we must check transmitter timeout here ? + * 14 Oct 1994 Dmitry Gorodchanin. + */ +#ifdef SL_CHECK_TRANSMIT + if (time_before(jiffies, dev_trans_start(dev) + 20 * HZ)) { + /* 20 sec timeout not reached */ + goto out; + } + printk(KERN_WARNING "%s: transmit timed out, %s?\n", + dev->name, + (tty_chars_in_buffer(sl->tty) || sl->xleft) ? + "bad line quality" : "driver error"); + sl->xleft = 0; + clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); + sl_unlock(sl); +#endif + } +out: + spin_unlock(&sl->lock); +} + + +/* Encapsulate an IP datagram and kick it into a TTY queue. */ +static netdev_tx_t +sl_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct slip *sl = netdev_priv(dev); + + spin_lock(&sl->lock); + if (!netif_running(dev)) { + spin_unlock(&sl->lock); + printk(KERN_WARNING "%s: xmit call when iface is down\n", dev->name); + dev_kfree_skb(skb); + return NETDEV_TX_OK; + } + if (sl->tty == NULL) { + spin_unlock(&sl->lock); + dev_kfree_skb(skb); + return NETDEV_TX_OK; + } + + sl_lock(sl); + dev->stats.tx_bytes += skb->len; + sl_encaps(sl, skb->data, skb->len); + spin_unlock(&sl->lock); + + dev_kfree_skb(skb); + return NETDEV_TX_OK; +} + + +/****************************************** + * Routines looking at netdevice side. + ******************************************/ + +/* Netdevice UP -> DOWN routine */ + +static int +sl_close(struct net_device *dev) +{ + struct slip *sl = netdev_priv(dev); + + spin_lock_bh(&sl->lock); + if (sl->tty) + /* TTY discipline is running. */ + clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); + netif_stop_queue(dev); + sl->rcount = 0; + sl->xleft = 0; + spin_unlock_bh(&sl->lock); + + return 0; +} + +/* Netdevice DOWN -> UP routine */ + +static int sl_open(struct net_device *dev) +{ + struct slip *sl = netdev_priv(dev); + + if (sl->tty == NULL) + return -ENODEV; + + sl->flags &= (1 << SLF_INUSE); + netif_start_queue(dev); + return 0; +} + +/* Netdevice change MTU request */ + +static int sl_change_mtu(struct net_device *dev, int new_mtu) +{ + struct slip *sl = netdev_priv(dev); + + return sl_realloc_bufs(sl, new_mtu); +} + +/* Netdevice get statistics request */ + +static void +sl_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats) +{ + struct net_device_stats *devstats = &dev->stats; +#ifdef SL_INCLUDE_CSLIP + struct slip *sl = netdev_priv(dev); + struct slcompress *comp = sl->slcomp; +#endif + stats->rx_packets = devstats->rx_packets; + stats->tx_packets = devstats->tx_packets; + stats->rx_bytes = devstats->rx_bytes; + stats->tx_bytes = devstats->tx_bytes; + stats->rx_dropped = devstats->rx_dropped; + stats->tx_dropped = devstats->tx_dropped; + stats->tx_errors = devstats->tx_errors; + stats->rx_errors = devstats->rx_errors; + stats->rx_over_errors = devstats->rx_over_errors; + +#ifdef SL_INCLUDE_CSLIP + if (comp) { + /* Generic compressed statistics */ + stats->rx_compressed = comp->sls_i_compressed; + stats->tx_compressed = comp->sls_o_compressed; + + /* Are we really still needs this? */ + stats->rx_fifo_errors += comp->sls_i_compressed; + stats->rx_dropped += comp->sls_i_tossed; + stats->tx_fifo_errors += comp->sls_o_compressed; + stats->collisions += comp->sls_o_misses; + } +#endif +} + +/* Netdevice register callback */ + +static int sl_init(struct net_device *dev) +{ + struct slip *sl = netdev_priv(dev); + + /* + * Finish setting up the DEVICE info. + */ + + dev->mtu = sl->mtu; + dev->type = ARPHRD_SLIP + sl->mode; +#ifdef SL_CHECK_TRANSMIT + dev->watchdog_timeo = 20*HZ; +#endif + return 0; +} + + +static void sl_uninit(struct net_device *dev) +{ + struct slip *sl = netdev_priv(dev); + + sl_free_bufs(sl); + /* Drop the slip_devs[] entry here rather than from the destructor: + * ndo_uninit runs under RTNL, so it cannot race sl_sync(). + */ + slip_devs[dev->base_addr] = NULL; +} + +/* Only for the slip_open() error path: register_netdevice() can fail before + * ndo_init, and then ndo_uninit is not called either. + */ +static void sl_free_netdev(struct net_device *dev) +{ + int i = dev->base_addr; + + slip_devs[i] = NULL; +} + +static const struct net_device_ops sl_netdev_ops = { + .ndo_init = sl_init, + .ndo_uninit = sl_uninit, + .ndo_open = sl_open, + .ndo_stop = sl_close, + .ndo_start_xmit = sl_xmit, + .ndo_get_stats64 = sl_get_stats64, + .ndo_change_mtu = sl_change_mtu, + .ndo_tx_timeout = sl_tx_timeout, +#ifdef CONFIG_SLIP_SMART + .ndo_siocdevprivate = sl_siocdevprivate, +#endif +}; + + +static void sl_setup(struct net_device *dev) +{ + dev->netdev_ops = &sl_netdev_ops; + dev->needs_free_netdev = true; + + dev->hard_header_len = 0; + dev->addr_len = 0; + dev->tx_queue_len = 10; + + /* MTU range: 68 - 65534 */ + dev->min_mtu = 68; + dev->max_mtu = 65534; + + /* New-style flags. */ + dev->flags = IFF_NOARP|IFF_POINTOPOINT|IFF_MULTICAST; +} + +/****************************************** + Routines looking at TTY side. + ******************************************/ + + +/* + * Handle the 'receiver data ready' interrupt. + * This function is called by the 'tty_io' module in the kernel when + * a block of SLIP data has been received, which can now be decapsulated + * and sent on to some IP layer for further processing. This will not + * be re-entered while running but other ldisc functions may be called + * in parallel + */ + +static void slip_receive_buf(struct tty_struct *tty, const u8 *cp, const u8 *fp, + size_t count) +{ + struct slip *sl = tty->disc_data; + + if (!sl || sl->magic != SLIP_MAGIC || !netif_running(sl->dev)) + return; + + spin_lock_bh(&sl->lock); + + /* Read the characters out of the buffer */ + while (count--) { + if (fp && *fp++) { + if (!test_and_set_bit(SLF_ERROR, &sl->flags)) + sl->dev->stats.rx_errors++; + cp++; + continue; + } +#ifdef CONFIG_SLIP_MODE_SLIP6 + if (sl->mode & SL_MODE_SLIP6) + slip_unesc6(sl, *cp++); + else +#endif + slip_unesc(sl, *cp++); + } + + spin_unlock_bh(&sl->lock); +} + +/************************************ + * slip_open helper routines. + ************************************/ + +/* Collect hanged up channels */ +static void sl_sync(void) +{ + int i; + struct net_device *dev; + struct slip *sl; + + for (i = 0; i < slip_maxdev; i++) { + dev = slip_devs[i]; + if (dev == NULL) + break; + + sl = netdev_priv(dev); + if (sl->tty || sl->leased) + continue; + if (dev->flags & IFF_UP) + dev_close(dev); + } +} + + +/* Find a free SLIP channel, and link in this `tty' line. */ +static struct slip *sl_alloc(void) +{ + int i; + char name[IFNAMSIZ]; + struct net_device *dev = NULL; + struct slip *sl; + + for (i = 0; i < slip_maxdev; i++) { + dev = slip_devs[i]; + if (dev == NULL) + break; + } + /* Sorry, too many, all slots in use */ + if (i >= slip_maxdev) + return NULL; + + sprintf(name, "sl%d", i); + dev = alloc_netdev(sizeof(*sl), name, NET_NAME_UNKNOWN, sl_setup); + if (!dev) + return NULL; + + dev->base_addr = i; + sl = netdev_priv(dev); + + /* Initialize channel control data */ + sl->magic = SLIP_MAGIC; + sl->dev = dev; + spin_lock_init(&sl->lock); + INIT_WORK(&sl->tx_work, slip_transmit); + sl->mode = SL_MODE_DEFAULT; +#ifdef CONFIG_SLIP_SMART + /* initialize timer_list struct */ + timer_setup(&sl->keepalive_timer, sl_keepalive, 0); + timer_setup(&sl->outfill_timer, sl_outfill, 0); +#endif + slip_devs[i] = dev; + return sl; +} + +/* + * Open the high-level part of the SLIP channel. + * This function is called by the TTY module when the + * SLIP line discipline is called for. Because we are + * sure the tty line exists, we only have to link it to + * a free SLIP channel... + * + * Called in process context serialized from other ldisc calls. + */ + +static int slip_open(struct tty_struct *tty) +{ + struct slip *sl; + int err; + + if (!capable(CAP_NET_ADMIN)) + return -EPERM; + + if (tty->ops->write == NULL) + return -EOPNOTSUPP; + + /* RTnetlink lock is misused here to serialize concurrent + opens of slip channels. There are better ways, but it is + the simplest one. + */ + rtnl_lock(); + + /* Collect hanged up channels. */ + sl_sync(); + + sl = tty->disc_data; + + err = -EEXIST; + /* First make sure we're not already connected. */ + if (sl && sl->magic == SLIP_MAGIC) + goto err_exit; + + /* OK. Find a free SLIP channel to use. */ + err = -ENFILE; + sl = sl_alloc(); + if (sl == NULL) + goto err_exit; + + sl->tty = tty; + tty->disc_data = sl; + sl->pid = current->pid; + + if (!test_bit(SLF_INUSE, &sl->flags)) { + /* Perform the low-level SLIP initialization. */ + err = sl_alloc_bufs(sl, SL_MTU); + if (err) + goto err_free_chan; + + set_bit(SLF_INUSE, &sl->flags); + + err = register_netdevice(sl->dev); + if (err) + goto err_free_bufs; + } + +#ifdef CONFIG_SLIP_SMART + if (sl->keepalive) { + sl->keepalive_timer.expires = jiffies + sl->keepalive * HZ; + add_timer(&sl->keepalive_timer); + } + if (sl->outfill) { + sl->outfill_timer.expires = jiffies + sl->outfill * HZ; + add_timer(&sl->outfill_timer); + } +#endif + + /* Done. We have linked the TTY line to a channel. */ + rtnl_unlock(); + tty->receive_room = 65536; /* We don't flow control */ + + /* TTY layer expects 0 on success */ + return 0; + +err_free_bufs: + sl_free_bufs(sl); + +err_free_chan: + sl->tty = NULL; + tty->disc_data = NULL; + clear_bit(SLF_INUSE, &sl->flags); + sl_free_netdev(sl->dev); + /* do not call free_netdev before rtnl_unlock */ + rtnl_unlock(); + free_netdev(sl->dev); + return err; + +err_exit: + rtnl_unlock(); + + /* Count references from TTY module */ + return err; +} + +/* + * Close down a SLIP channel. + * This means flushing out any pending queues, and then returning. This + * call is serialized against other ldisc functions. + */ + +static void slip_close(struct tty_struct *tty) +{ + struct slip *sl = tty->disc_data; + + /* First make sure we're connected. */ + if (!sl || sl->magic != SLIP_MAGIC || sl->tty != tty) + return; + + spin_lock_bh(&sl->lock); + rcu_assign_pointer(tty->disc_data, NULL); + sl->tty = NULL; + spin_unlock_bh(&sl->lock); + + synchronize_rcu(); + flush_work(&sl->tx_work); + + /* VSV = very important to remove timers */ +#ifdef CONFIG_SLIP_SMART + timer_delete_sync(&sl->keepalive_timer); + timer_delete_sync(&sl->outfill_timer); +#endif + /* Flush network side */ + unregister_netdev(sl->dev); + /* sl_uninit() has dropped the slip_devs[] entry by now */ +} + /************************************************************************ + * STANDARD SLIP ENCAPSULATION * + ************************************************************************/ + +static int slip_esc(unsigned char *s, unsigned char *d, int len) +{ + unsigned char *ptr = d; + unsigned char c; + + /* + * Send an initial END character to flush out any + * data that may have accumulated in the receiver + * due to line noise. + */ + + *ptr++ = END; + + /* + * For each byte in the packet, send the appropriate + * character sequence, according to the SLIP protocol. + */ + + while (len-- > 0) { + switch (c = *s++) { + case END: + *ptr++ = ESC; + *ptr++ = ESC_END; + break; + case ESC: + *ptr++ = ESC; + *ptr++ = ESC_ESC; + break; + default: + *ptr++ = c; + break; + } + } + *ptr++ = END; + return ptr - d; +} + +static void slip_unesc(struct slip *sl, unsigned char s) +{ + + switch (s) { + case END: +#ifdef CONFIG_SLIP_SMART + /* drop keeptest bit = VSV */ + if (test_bit(SLF_KEEPTEST, &sl->flags)) + clear_bit(SLF_KEEPTEST, &sl->flags); +#endif + + if (!test_and_clear_bit(SLF_ERROR, &sl->flags) && + (sl->rcount > 2)) + sl_bump(sl); + clear_bit(SLF_ESCAPE, &sl->flags); + sl->rcount = 0; + return; + + case ESC: + set_bit(SLF_ESCAPE, &sl->flags); + return; + case ESC_ESC: + if (test_and_clear_bit(SLF_ESCAPE, &sl->flags)) + s = ESC; + break; + case ESC_END: + if (test_and_clear_bit(SLF_ESCAPE, &sl->flags)) + s = END; + break; + } + if (!test_bit(SLF_ERROR, &sl->flags)) { + if (sl->rcount < sl->buffsize) { + sl->rbuff[sl->rcount++] = s; + return; + } + sl->dev->stats.rx_over_errors++; + set_bit(SLF_ERROR, &sl->flags); + } +} + + +#ifdef CONFIG_SLIP_MODE_SLIP6 +/************************************************************************ + * 6 BIT SLIP ENCAPSULATION * + ************************************************************************/ + +static int slip_esc6(unsigned char *s, unsigned char *d, int len) +{ + unsigned char *ptr = d; + unsigned char c; + int i; + unsigned short v = 0; + short bits = 0; + + /* + * Send an initial END character to flush out any + * data that may have accumulated in the receiver + * due to line noise. + */ + + *ptr++ = 0x70; + + /* + * Encode the packet into printable ascii characters + */ + + for (i = 0; i < len; ++i) { + v = (v << 8) | s[i]; + bits += 8; + while (bits >= 6) { + bits -= 6; + c = 0x30 + ((v >> bits) & 0x3F); + *ptr++ = c; + } + } + if (bits) { + c = 0x30 + ((v << (6 - bits)) & 0x3F); + *ptr++ = c; + } + *ptr++ = 0x70; + return ptr - d; +} + +static void slip_unesc6(struct slip *sl, unsigned char s) +{ + unsigned char c; + + if (s == 0x70) { +#ifdef CONFIG_SLIP_SMART + /* drop keeptest bit = VSV */ + if (test_bit(SLF_KEEPTEST, &sl->flags)) + clear_bit(SLF_KEEPTEST, &sl->flags); +#endif + + if (!test_and_clear_bit(SLF_ERROR, &sl->flags) && + (sl->rcount > 2)) + sl_bump(sl); + sl->rcount = 0; + sl->xbits = 0; + sl->xdata = 0; + } else if (s >= 0x30 && s < 0x70) { + sl->xdata = (sl->xdata << 6) | ((s - 0x30) & 0x3F); + sl->xbits += 6; + if (sl->xbits >= 8) { + sl->xbits -= 8; + c = (unsigned char)(sl->xdata >> sl->xbits); + if (!test_bit(SLF_ERROR, &sl->flags)) { + if (sl->rcount < sl->buffsize) { + sl->rbuff[sl->rcount++] = c; + return; + } + sl->dev->stats.rx_over_errors++; + set_bit(SLF_ERROR, &sl->flags); + } + } + } +} +#endif /* CONFIG_SLIP_MODE_SLIP6 */ + +/* Perform I/O control on an active SLIP channel. */ +static int slip_ioctl(struct tty_struct *tty, unsigned int cmd, + unsigned long arg) +{ + struct slip *sl = tty->disc_data; + unsigned int tmp; + int __user *p = (int __user *)arg; + + /* First make sure we're connected. */ + if (!sl || sl->magic != SLIP_MAGIC) + return -EINVAL; + + switch (cmd) { + case SIOCGIFNAME: + tmp = strlen(sl->dev->name) + 1; + if (copy_to_user((void __user *)arg, sl->dev->name, tmp)) + return -EFAULT; + return 0; + + case SIOCGIFENCAP: + if (put_user(sl->mode, p)) + return -EFAULT; + return 0; + + case SIOCSIFENCAP: + if (get_user(tmp, p)) + return -EFAULT; +#ifndef SL_INCLUDE_CSLIP + if (tmp & (SL_MODE_CSLIP|SL_MODE_ADAPTIVE)) + return -EINVAL; +#else + if ((tmp & (SL_MODE_ADAPTIVE | SL_MODE_CSLIP)) == + (SL_MODE_ADAPTIVE | SL_MODE_CSLIP)) + /* return -EINVAL; */ + tmp &= ~SL_MODE_ADAPTIVE; +#endif +#ifndef CONFIG_SLIP_MODE_SLIP6 + if (tmp & SL_MODE_SLIP6) + return -EINVAL; +#endif + sl->mode = tmp; + sl->dev->type = ARPHRD_SLIP + sl->mode; + return 0; + + case SIOCSIFHWADDR: + return -EINVAL; + +#ifdef CONFIG_SLIP_SMART + /* VSV changes start here */ + case SIOCSKEEPALIVE: + if (get_user(tmp, p)) + return -EFAULT; + if (tmp > 255) /* max for unchar */ + return -EINVAL; + + spin_lock_bh(&sl->lock); + if (!sl->tty) { + spin_unlock_bh(&sl->lock); + return -ENODEV; + } + sl->keepalive = (u8)tmp; + if (sl->keepalive != 0) { + mod_timer(&sl->keepalive_timer, + jiffies + sl->keepalive * HZ); + set_bit(SLF_KEEPTEST, &sl->flags); + } else + timer_delete(&sl->keepalive_timer); + spin_unlock_bh(&sl->lock); + return 0; + + case SIOCGKEEPALIVE: + if (put_user(sl->keepalive, p)) + return -EFAULT; + return 0; + + case SIOCSOUTFILL: + if (get_user(tmp, p)) + return -EFAULT; + if (tmp > 255) /* max for unchar */ + return -EINVAL; + spin_lock_bh(&sl->lock); + if (!sl->tty) { + spin_unlock_bh(&sl->lock); + return -ENODEV; + } + sl->outfill = (u8)tmp; + if (sl->outfill != 0) { + mod_timer(&sl->outfill_timer, + jiffies + sl->outfill * HZ); + set_bit(SLF_OUTWAIT, &sl->flags); + } else + timer_delete(&sl->outfill_timer); + spin_unlock_bh(&sl->lock); + return 0; + + case SIOCGOUTFILL: + if (put_user(sl->outfill, p)) + return -EFAULT; + return 0; + /* VSV changes end */ +#endif + default: + return tty_mode_ioctl(tty, cmd, arg); + } +} + +/* VSV changes start here */ +#ifdef CONFIG_SLIP_SMART +/* function sl_siocdevprivate called from net/core/dev.c + to allow get/set outfill/keepalive parameter + by ifconfig */ + +static int sl_siocdevprivate(struct net_device *dev, struct ifreq *rq, + void __user *data, int cmd) +{ + struct slip *sl = netdev_priv(dev); + unsigned long *p = (unsigned long *)&rq->ifr_ifru; + + if (sl == NULL) /* Allocation failed ?? */ + return -ENODEV; + + if (in_compat_syscall()) + return -EOPNOTSUPP; + + spin_lock_bh(&sl->lock); + + if (!sl->tty) { + spin_unlock_bh(&sl->lock); + return -ENODEV; + } + + switch (cmd) { + case SIOCSKEEPALIVE: + /* max for unchar */ + if ((unsigned)*p > 255) { + spin_unlock_bh(&sl->lock); + return -EINVAL; + } + sl->keepalive = (u8)*p; + if (sl->keepalive != 0) { + sl->keepalive_timer.expires = + jiffies + sl->keepalive * HZ; + mod_timer(&sl->keepalive_timer, + jiffies + sl->keepalive * HZ); + set_bit(SLF_KEEPTEST, &sl->flags); + } else + timer_delete(&sl->keepalive_timer); + break; + + case SIOCGKEEPALIVE: + *p = sl->keepalive; + break; + + case SIOCSOUTFILL: + if ((unsigned)*p > 255) { /* max for unchar */ + spin_unlock_bh(&sl->lock); + return -EINVAL; + } + sl->outfill = (u8)*p; + if (sl->outfill != 0) { + mod_timer(&sl->outfill_timer, + jiffies + sl->outfill * HZ); + set_bit(SLF_OUTWAIT, &sl->flags); + } else + timer_delete(&sl->outfill_timer); + break; + + case SIOCGOUTFILL: + *p = sl->outfill; + break; + + case SIOCSLEASE: + /* Resolve race condition, when ioctl'ing hanged up + and opened by another process device. + */ + if (sl->tty != current->signal->tty && + sl->pid != current->pid) { + spin_unlock_bh(&sl->lock); + return -EPERM; + } + sl->leased = 0; + if (*p) + sl->leased = 1; + break; + + case SIOCGLEASE: + *p = sl->leased; + } + spin_unlock_bh(&sl->lock); + return 0; +} +#endif +/* VSV changes end */ + +static struct tty_ldisc_ops sl_ldisc = { + .owner = THIS_MODULE, + .num = N_SLIP, + .name = "slip", + .open = slip_open, + .close = slip_close, + .ioctl = slip_ioctl, + .receive_buf = slip_receive_buf, + .write_wakeup = slip_write_wakeup, +}; + +static int __init slip_init(void) +{ + int status; + + if (slip_maxdev < 4) + slip_maxdev = 4; /* Sanity */ + + printk(KERN_INFO "SLIP: version %s (dynamic channels, max=%d)" +#ifdef CONFIG_SLIP_MODE_SLIP6 + " (6 bit encapsulation enabled)" +#endif + ".\n", + SLIP_VERSION, slip_maxdev); +#if defined(SL_INCLUDE_CSLIP) + printk(KERN_INFO "CSLIP: code copyright 1989 Regents of the University of California.\n"); +#endif +#ifdef CONFIG_SLIP_SMART + printk(KERN_INFO "SLIP linefill/keepalive option.\n"); +#endif + + slip_devs = kzalloc_objs(struct net_device *, slip_maxdev); + if (!slip_devs) + return -ENOMEM; + + /* Fill in our line protocol discipline, and register it */ + status = tty_register_ldisc(&sl_ldisc); + if (status != 0) { + printk(KERN_ERR "SLIP: can't register line discipline (err = %d)\n", status); + kfree(slip_devs); + } + return status; +} + +static void __exit slip_exit(void) +{ + int i; + struct net_device *dev; + struct slip *sl; + unsigned long timeout = jiffies + HZ; + int busy = 0; + + if (slip_devs == NULL) + return; + + /* First of all: check for active disciplines and hangup them. + */ + do { + if (busy) + msleep_interruptible(100); + + busy = 0; + for (i = 0; i < slip_maxdev; i++) { + dev = slip_devs[i]; + if (!dev) + continue; + sl = netdev_priv(dev); + spin_lock_bh(&sl->lock); + if (sl->tty) { + busy++; + tty_hangup(sl->tty); + } + spin_unlock_bh(&sl->lock); + } + } while (busy && time_before(jiffies, timeout)); + + /* FIXME: hangup is async so we should wait when doing this second + phase */ + + for (i = 0; i < slip_maxdev; i++) { + dev = slip_devs[i]; + if (!dev) + continue; + slip_devs[i] = NULL; + + sl = netdev_priv(dev); + if (sl->tty) { + printk(KERN_ERR "%s: tty discipline still running\n", + dev->name); + } + + unregister_netdev(dev); + } + + kfree(slip_devs); + slip_devs = NULL; + + tty_unregister_ldisc(&sl_ldisc); +} + +module_init(slip_init); +module_exit(slip_exit); + +#ifdef CONFIG_SLIP_SMART +/* + * This is start of the code for multislip style line checking + * added by Stanislav Voronyi. All changes before marked VSV + */ + +static void sl_outfill(struct timer_list *t) +{ + struct slip *sl = timer_container_of(sl, t, outfill_timer); + + spin_lock(&sl->lock); + + if (sl->tty == NULL) + goto out; + + if (sl->outfill) { + if (test_bit(SLF_OUTWAIT, &sl->flags)) { + /* no packets were transmitted, do outfill */ +#ifdef CONFIG_SLIP_MODE_SLIP6 + unsigned char s = (sl->mode & SL_MODE_SLIP6)?0x70:END; +#else + unsigned char s = END; +#endif + /* put END into tty queue. Is it right ??? */ + if (!netif_queue_stopped(sl->dev)) { + /* if device busy no outfill */ + sl->tty->ops->write(sl->tty, &s, 1); + } + } else + set_bit(SLF_OUTWAIT, &sl->flags); + + mod_timer(&sl->outfill_timer, jiffies+sl->outfill*HZ); + } +out: + spin_unlock(&sl->lock); +} + +static void sl_keepalive(struct timer_list *t) +{ + struct slip *sl = timer_container_of(sl, t, keepalive_timer); + + spin_lock(&sl->lock); + + if (sl->tty == NULL) + goto out; + + if (sl->keepalive) { + if (test_bit(SLF_KEEPTEST, &sl->flags)) { + /* keepalive still high :(, we must hangup */ + if (sl->outfill) + /* outfill timer must be deleted too */ + (void) timer_delete(&sl->outfill_timer); + printk(KERN_DEBUG "%s: no packets received during keepalive timeout, hangup.\n", sl->dev->name); + /* this must hangup tty & close slip */ + tty_hangup(sl->tty); + /* I think we need not something else */ + goto out; + } else + set_bit(SLF_KEEPTEST, &sl->flags); + + mod_timer(&sl->keepalive_timer, jiffies+sl->keepalive*HZ); + } +out: + spin_unlock(&sl->lock); +} + +#endif +MODULE_DESCRIPTION("SLIP (serial line) protocol module"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_LDISC(N_SLIP); diff --git a/drivers/net/slip/slip.h b/drivers/net/slip/slip.h new file mode 100644 index 000000000..3d7f88b33 --- /dev/null +++ b/drivers/net/slip/slip.h @@ -0,0 +1,105 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * slip.h Define the SLIP device driver interface and constants. + * + * NOTE: THIS FILE WILL BE MOVED TO THE LINUX INCLUDE DIRECTORY + * AS SOON AS POSSIBLE! + * + * Version: @(#)slip.h 1.2.0 03/28/93 + * + * Fixes: + * Alan Cox : Added slip mtu field. + * Matt Dillon : Printable slip (borrowed from net2e) + * Alan Cox : Added SL_SLIP_LOTS + * Dmitry Gorodchanin : A lot of changes in the 'struct slip' + * Dmitry Gorodchanin : Added CSLIP statistics. + * Stanislav Voronyi : Make line checking as created by + * Igor Chechik, RELCOM Corp. + * Craig Schlenter : Fixed #define bug that caused + * CSLIP telnets to hang in 1.3.61-6 + * + * Author: Fred N. van Kempen, + */ +#ifndef _LINUX_SLIP_H +#define _LINUX_SLIP_H + + +#if defined(CONFIG_INET) && defined(CONFIG_SLIP_COMPRESSED) +# define SL_INCLUDE_CSLIP +#endif + +#ifdef SL_INCLUDE_CSLIP +# define SL_MODE_DEFAULT SL_MODE_ADAPTIVE +#else +# define SL_MODE_DEFAULT SL_MODE_SLIP +#endif + +/* SLIP configuration. */ +#define SL_NRUNIT 256 /* MAX number of SLIP channels; + This can be overridden with + insmod -oslip_maxdev=nnn */ +#define SL_MTU 296 /* 296; I am used to 600- FvK */ + +/* some arch define END as assembly function ending, just undef it */ +#undef END +/* SLIP protocol characters. */ +#define END 0300 /* indicates end of frame */ +#define ESC 0333 /* indicates byte stuffing */ +#define ESC_END 0334 /* ESC ESC_END means END 'data' */ +#define ESC_ESC 0335 /* ESC ESC_ESC means ESC 'data' */ + + +struct slip { + int magic; + + /* Various fields. */ + struct tty_struct *tty; /* ptr to TTY structure */ + struct net_device *dev; /* easy for intr handling */ + spinlock_t lock; + struct work_struct tx_work; /* Flushes transmit buffer */ + +#ifdef SL_INCLUDE_CSLIP + struct slcompress *slcomp; /* for header compression */ + unsigned char *cbuff; /* compression buffer */ +#endif + + /* These are pointers to the malloc()ed frame buffers. */ + unsigned char *rbuff; /* receiver buffer */ + int rcount; /* received chars counter */ + unsigned char *xbuff; /* transmitter buffer */ + unsigned char *xhead; /* pointer to next byte to XMIT */ + int xleft; /* bytes left in XMIT queue */ + int mtu; /* Our mtu (to spot changes!) */ + int buffsize; /* Max buffers sizes */ + +#ifdef CONFIG_SLIP_MODE_SLIP6 + int xdata, xbits; /* 6 bit slip controls */ +#endif + + unsigned long flags; /* Flag values/ mode etc */ +#define SLF_INUSE 0 /* Channel in use */ +#define SLF_ESCAPE 1 /* ESC received */ +#define SLF_ERROR 2 /* Parity, etc. error */ +#define SLF_KEEPTEST 3 /* Keepalive test flag */ +#define SLF_OUTWAIT 4 /* is outpacket was flag */ + + unsigned char mode; /* SLIP mode */ + unsigned char leased; + pid_t pid; +#define SL_MODE_SLIP 0 +#define SL_MODE_CSLIP 1 +#define SL_MODE_SLIP6 2 /* Matt Dillon's printable slip */ +#define SL_MODE_CSLIP6 (SL_MODE_SLIP6|SL_MODE_CSLIP) +#define SL_MODE_AX25 4 +#define SL_MODE_ADAPTIVE 8 +#ifdef CONFIG_SLIP_SMART + unsigned char outfill; /* # of sec between outfill packet */ + unsigned char keepalive; /* keepalive seconds */ + struct timer_list outfill_timer; + struct timer_list keepalive_timer; +#endif +}; + +#define SLIP_MAGIC 0x5302 + +#endif /* _LINUX_SLIP.H */ -- cgit v1.3.1