From c5c63975d538cf48ceb99ba48c341293676d15c0 Mon Sep 17 00:00:00 2001 From: julian Date: Thu, 21 Oct 1999 09:06:11 +0000 Subject: Whistle's Netgraph link-layer (sometimes more) networking infrastructure. Been in production for 3 years now. Gives Instant Frame relay to if_sr and if_ar drivers, and PPPOE support soon. See: ftp://ftp.whistle.com/pub/archie/netgraph/index.html for on-line manual pages. Reviewed by: Doug Rabson (dfr@freebsd.org) Obtained from: Whistle CVS tree --- sys/netgraph/ng_frame_relay.c | 526 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 526 insertions(+) create mode 100644 sys/netgraph/ng_frame_relay.c (limited to 'sys/netgraph/ng_frame_relay.c') diff --git a/sys/netgraph/ng_frame_relay.c b/sys/netgraph/ng_frame_relay.c new file mode 100644 index 0000000..995b769 --- /dev/null +++ b/sys/netgraph/ng_frame_relay.c @@ -0,0 +1,526 @@ + +/* + * ng_frame_relay.c + * + * Copyright (c) 1996-1999 Whistle Communications, Inc. + * All rights reserved. + * + * Subject to the following obligations and disclaimer of warranty, use and + * redistribution of this software, in source or object code forms, with or + * without modifications are expressly permitted by Whistle Communications; + * provided, however, that: + * 1. Any and all reproductions of the source or object code must include the + * copyright notice above and the following disclaimer of warranties; and + * 2. No rights are granted, in any manner or form, to use Whistle + * Communications, Inc. trademarks, including the mark "WHISTLE + * COMMUNICATIONS" on advertising, endorsements, or otherwise except as + * such appears in the above copyright notice or in the software. + * + * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND + * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO + * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE, + * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. + * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY + * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS + * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE. + * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES + * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING + * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, + * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * Author: Julian Elisher + * + * $FreeBSD$ + * $Whistle: ng_frame_relay.c,v 1.16 1999/01/28 23:54:53 julian Exp $ + */ + +/* + * This node implements the frame relay protocol, not including + * the LMI line management. This means basically keeping track + * of which DLCI's are active, doing frame (de)multiplexing, etc. + * + * It has a 'downstream' hook that goes to the line, and a + * hook for each DLCI (eg, 'dlci16'). + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +/* + * Line info, and status per channel. + */ +struct ctxinfo { /* one per active hook */ + u_int flags; +#define CHAN_VALID 0x01 /* assigned to a channel */ +#define CHAN_ACTIVE 0x02 /* bottom level active */ + int dlci; /* the dlci assigned to this context */ + hook_p hook; /* if there's a hook assigned.. */ +}; + +#define MAX_CT 16 /* # of dlci's active at a time (POWER OF 2!) */ +struct frmrel_softc { + int unit; /* which card are we? */ + char nodename[NG_NODELEN + 1]; /* store our node name */ + int datahooks; /* number of data hooks attached */ + node_p node; /* netgraph node */ + int addrlen; /* address header length */ + int flags; /* state */ + int mtu; /* guess */ + u_char remote_seq; /* sequence number the remote sent */ + u_char local_seq; /* sequence number the remote rcvd */ + u_short ALT[1024]; /* map DLCIs to CTX */ +#define CTX_VALID 0x8000 /* this bit means it's a valid CTX */ +#define CTX_VALUE (MAX_CT - 1) /* mask for context part */ + struct ctxinfo channel[MAX_CT]; + struct ctxinfo downstream; +}; +typedef struct frmrel_softc *sc_p; + +#define BYTEX_EA 0x01 /* End Address. Always 0 on byte1 */ +#define BYTE1_C_R 0x02 +#define BYTE2_FECN 0x08 /* forwards congestion notification */ +#define BYTE2_BECN 0x04 /* Backward congestion notification */ +#define BYTE2_DE 0x02 /* Discard elligability */ +#define LASTBYTE_D_C 0x02 /* last byte is dl_core or dlci info */ + +/* Used to do headers */ +static struct segment { + u_char mask; + u_char shift; + u_char width; +} makeup[] = { + { 0xfc, 2, 6 }, + { 0xf0, 4, 4 }, + { 0xfe, 1, 7 }, + { 0xfc, 2, 6 } +}; + +#define SHIFTIN(segment, byte, dlci) \ + { \ + (dlci) <<= (segment)->width; \ + (dlci) |= \ + (((byte) & (segment)->mask) >> (segment)->shift); \ + } + +#define SHIFTOUT(segment, byte, dlci) \ + { \ + (byte) |= (((dlci) << (segment)->shift) & (segment)->mask); \ + (dlci) >>= (segment)->width; \ + } + +/* Netgraph methods */ +static int ngfrm_constructor(node_p *nodep); +static int ngfrm_rmnode(node_p node); +static int ngfrm_newhook(node_p node, hook_p hook, const char *name); +static int ngfrm_rcvdata(hook_p hook, struct mbuf *m, meta_p meta); +static int ngfrm_disconnect(hook_p hook); + +/* Other internal functions */ +static int ngfrm_decode(node_p node, struct mbuf * m, meta_p meta); +static int ngfrm_addrlen(char *hdr); +static int ngfrm_allocate_CTX(sc_p sc, int dlci); + +/* Netgraph type */ +static struct ng_type typestruct = { + NG_VERSION, + NG_FRAMERELAY_NODE_TYPE, + NULL, + ngfrm_constructor, + NULL, + ngfrm_rmnode, + ngfrm_newhook, + NULL, + NULL, + ngfrm_rcvdata, + ngfrm_rcvdata, + ngfrm_disconnect +}; +NETGRAPH_INIT(framerelay, &typestruct); + +/* + * Given a DLCI, return the index of the context table entry for it, + * Allocating a new one if needs be, or -1 if none available. + */ +static int +ngfrm_allocate_CTX(sc_p sc, int dlci) +{ + u_int ctxnum = -1; /* what ctx number we are using */ + volatile struct ctxinfo *CTXp = NULL; + + /* Sanity check the dlci value */ + if (dlci > 1023) + return (-1); + + /* Check to see if we already have an entry for this DLCI */ + if (sc->ALT[dlci]) { + if ((ctxnum = sc->ALT[dlci] & CTX_VALUE) < MAX_CT) { + CTXp = sc->channel + ctxnum; + } else { + ctxnum = -1; + sc->ALT[dlci] = 0; /* paranoid but... */ + } + } + + /* + * If the index has no valid entry yet, then we need to allocate a + * CTX number to it + */ + if (CTXp == NULL) { + for (ctxnum = 0; ctxnum < MAX_CT; ctxnum++) { + /* + * If the VALID flag is empty it is unused + */ + if ((sc->channel[ctxnum].flags & CHAN_VALID) == 0) { + bzero(sc->channel + ctxnum, + sizeof(struct ctxinfo)); + CTXp = sc->channel + ctxnum; + sc->ALT[dlci] = ctxnum | CTX_VALID; + sc->channel[ctxnum].dlci = dlci; + sc->channel[ctxnum].flags = CHAN_VALID; + break; + } + } + } + + /* + * If we still don't have a CTX pointer, then we never found a free + * spot so give up now.. + */ + if (!CTXp) { + log(LOG_ERR, "No CTX available for dlci %d\n", dlci); + return (-1); + } + return (ctxnum); +} + +/* + * Node constructor + */ +static int +ngfrm_constructor(node_p *nodep) +{ + sc_p sc; + int error = 0; + + MALLOC(sc, sc_p, sizeof(*sc), M_NETGRAPH, M_NOWAIT); + if (!sc) + return (ENOMEM); + bzero(sc, sizeof(*sc)); + if ((error = ng_make_node_common(&typestruct, nodep))) { + FREE(sc, M_NETGRAPH); + return (error); + } + sc->addrlen = 2; /* default */ + + /* Link the node and our private info */ + (*nodep)->private = sc; + sc->node = *nodep; + return (0); +} + +/* + * Add a new hook + * + * We allow hooks called "debug", "downstream" and dlci[0-1023] + * The hook's private info points to our stash of info about that + * channel. A NULL pointer is debug and a DLCI of -1 means downstream. + */ +static int +ngfrm_newhook(node_p node, hook_p hook, const char *name) +{ + const sc_p sc = node->private; + const char *cp; + char c = '\0'; + int digits = 0; + int dlci = 0; + int ctxnum; + + /* Check if it's our friend the control hook */ + if (strcmp(name, NG_FRAMERELAY_HOOK_DEBUG) == 0) { + hook->private = NULL; /* paranoid */ + return (0); + } + + /* + * All other hooks either start with 'dlci' and have a decimal + * trailing channel number up to 4 digits, or are the downstream + * hook. + */ + if (strncmp(name, NG_FRAMERELAY_HOOK_DLCI, + strlen(NG_FRAMERELAY_HOOK_DLCI)) != 0) { + + /* It must be the downstream connection */ + if (strcmp(name, NG_FRAMERELAY_HOOK_DOWNSTREAM) != 0) + return EINVAL; + + /* Make sure we haven't already got one (paranoid) */ + if (sc->downstream.hook) + return (EADDRINUSE); + + /* OK add it */ + hook->private = &sc->downstream; + sc->downstream.hook = hook; + sc->downstream.dlci = -1; + sc->downstream.flags |= CHAN_ACTIVE; + sc->datahooks++; + return (0); + } + + /* Must be a dlci hook at this point */ + cp = name + strlen(NG_FRAMERELAY_HOOK_DLCI); + while ((digits < 5) && ((c = *cp++) >= '0') && (c <= '9')) { + dlci *= 10; + dlci += c - '0'; + digits++; + } + if ((c != 0) || (digits == 5) || (dlci < 0) || (dlci > 1023)) + return (EINVAL); + /* + * We have a dlci, now either find it, or allocate it. It's possible + * that we might have seen packets for it already and made an entry + * for it. + */ + ctxnum = ngfrm_allocate_CTX(sc, dlci); + if (ctxnum == -1) + return (ENOBUFS); + + /* + * Be paranoid: if it's got a hook already, that dlci is in use . + * Generic code can not catch all the synonyms (e.g. dlci016 vs + * dlci16) + */ + if (sc->channel[ctxnum].hook != NULL) + return (EADDRINUSE); + + /* + * Put our hooks into it (pun not intended) + */ + sc->channel[ctxnum].flags |= CHAN_ACTIVE; + hook->private = sc->channel + ctxnum; + sc->channel[ctxnum].hook = hook; + sc->datahooks++; + return (0); +} + +/* + * Count up the size of the address header if we don't already know + */ +int +ngfrm_addrlen(char *hdr) +{ + if (hdr[0] & BYTEX_EA) + return 0; + if (hdr[1] & BYTEX_EA) + return 2; + if (hdr[2] & BYTEX_EA) + return 3; + if (hdr[3] & BYTEX_EA) + return 4; + return 0; +} + +/* + * Receive data packet + */ +static int +ngfrm_rcvdata(hook_p hook, struct mbuf *m, meta_p meta) +{ + struct ctxinfo *const ctxp = hook->private; + int error = 0; + int dlci; + sc_p sc; + int alen; + char *data; + + /* Data doesn't come in from just anywhere (e.g debug hook) */ + if (ctxp == NULL) { + error = ENETDOWN; + goto bad; + } + + /* If coming from downstream, decode it to a channel */ + dlci = ctxp->dlci; + if (dlci == -1) + return (ngfrm_decode(hook->node, m, meta)); + + /* Derive the softc we will need */ + sc = hook->node->private; + + /* If there is no live channel, throw it away */ + if ((sc->downstream.hook == NULL) + || ((ctxp->flags & CHAN_ACTIVE) == 0)) { + error = ENETDOWN; + goto bad; + } + + /* Store the DLCI on the front of the packet */ + alen = sc->addrlen; + if (alen == 0) + alen = 2; /* default value for transmit */ + M_PREPEND(m, alen, M_DONTWAIT); + if (m == NULL) { + error = ENOBUFS; + goto bad; + } + data = mtod(m, char *); + + /* + * Shift the lowest bits into the address field untill we are done. + * First byte is MSBits of addr so work backwards. + */ + switch (alen) { + case 2: + data[0] = data[1] = '\0'; + SHIFTOUT(makeup + 1, data[1], dlci); + SHIFTOUT(makeup + 0, data[0], dlci); + data[1] |= BYTEX_EA; + break; + case 3: + data[0] = data[1] = data[2] = '\0'; + SHIFTOUT(makeup + 3, data[2], dlci); /* 3 and 2 is correct */ + SHIFTOUT(makeup + 1, data[1], dlci); + SHIFTOUT(makeup + 0, data[0], dlci); + data[2] |= BYTEX_EA; + break; + case 4: + data[0] = data[1] = data[2] = data[3] = '\0'; + SHIFTOUT(makeup + 3, data[3], dlci); + SHIFTOUT(makeup + 2, data[2], dlci); + SHIFTOUT(makeup + 1, data[1], dlci); + SHIFTOUT(makeup + 0, data[0], dlci); + data[3] |= BYTEX_EA; + break; + default: + panic(__FUNCTION__); + } + + /* Send it */ + NG_SEND_DATA(error, sc->downstream.hook, m, meta); + return (error); + +bad: + NG_FREE_DATA(m, meta); + return (error); +} + +/* + * Decode an incoming frame coming from the switch + */ +static int +ngfrm_decode(node_p node, struct mbuf *m, meta_p meta) +{ + const sc_p sc = node->private; + char *data; + int alen; + u_int dlci = 0; + int error = 0; + int ctxnum; + + if ((m = m_pullup(m, 4)) == NULL) { + error = ENOBUFS; + goto out; + } + data = mtod(m, char *); + if ((alen = sc->addrlen) == 0) { + sc->addrlen = alen = ngfrm_addrlen(data); + } + switch (alen) { + case 2: + SHIFTIN(makeup + 0, data[0], dlci); + SHIFTIN(makeup + 1, data[1], dlci); + break; + case 3: + SHIFTIN(makeup + 0, data[0], dlci); + SHIFTIN(makeup + 1, data[1], dlci); + SHIFTIN(makeup + 3, data[2], dlci); /* 3 and 2 is correct */ + break; + case 4: + SHIFTIN(makeup + 0, data[0], dlci); + SHIFTIN(makeup + 1, data[1], dlci); + SHIFTIN(makeup + 2, data[2], dlci); + SHIFTIN(makeup + 3, data[3], dlci); + break; + default: + error = EINVAL; + goto out; + } + + if (dlci > 1023) { + error = EINVAL; + goto out; + } + ctxnum = sc->ALT[dlci]; + if ((ctxnum & CTX_VALID) && sc->channel[ctxnum &= CTX_VALUE].hook) { + /* Send it */ + m_adj(m, alen); + NG_SEND_DATA(error, sc->channel[ctxnum].hook, m, meta); + return (error); + } else { + error = ENETDOWN; + } +out: + NG_FREE_DATA(m, meta); + return (error); +} + +/* + * Shutdown node + */ +static int +ngfrm_rmnode(node_p node) +{ + const sc_p sc = node->private; + + node->flags |= NG_INVALID; + ng_cutlinks(node); + ng_unname(node); + node->private = NULL; + FREE(sc, M_NETGRAPH); + ng_unref(sc->node); + return (0); +} + +/* + * Hook disconnection + * + * Invalidate the private data associated with this dlci. + * For this type, removal of the last link resets tries to destroy the node. + */ +static int +ngfrm_disconnect(hook_p hook) +{ + const sc_p sc = hook->node->private; + struct ctxinfo *const cp = hook->private; + int dlci; + + /* If it's a regular dlci hook, then free resources etc.. */ + if (cp != NULL) { + cp->hook = NULL; + dlci = cp->dlci; + if (dlci != -1) + sc->ALT[dlci] = 0; + cp->flags = 0; + sc->datahooks--; + } + if (hook->node->numhooks == 0) + ng_rmnode(hook->node); + return (0); +} -- cgit v1.1