diff options
Diffstat (limited to 'net/decnet/dn_nsp_in.c')
| -rw-r--r-- | net/decnet/dn_nsp_in.c | 917 |
1 files changed, 917 insertions, 0 deletions
diff --git a/net/decnet/dn_nsp_in.c b/net/decnet/dn_nsp_in.c new file mode 100644 index 000000000..a321eac9f --- /dev/null +++ b/net/decnet/dn_nsp_in.c @@ -0,0 +1,917 @@ +/* + * DECnet An implementation of the DECnet protocol suite for the LINUX + * operating system. DECnet is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * DECnet Network Services Protocol (Input) + * + * Author: Eduardo Marcelo Serrat <emserrat@geocities.com> + * + * Changes: + * + * Steve Whitehouse: Split into dn_nsp_in.c and dn_nsp_out.c from + * original dn_nsp.c. + * Steve Whitehouse: Updated to work with my new routing architecture. + * Steve Whitehouse: Add changes from Eduardo Serrat's patches. + * Steve Whitehouse: Put all ack handling code in a common routine. + * Steve Whitehouse: Put other common bits into dn_nsp_rx() + * Steve Whitehouse: More checks on skb->len to catch bogus packets + * Fixed various race conditions and possible nasties. + * Steve Whitehouse: Now handles returned conninit frames. + * David S. Miller: New socket locking + * Steve Whitehouse: Fixed lockup when socket filtering was enabled. + * Paul Koning: Fix to push CC sockets into RUN when acks are + * received. + * Steve Whitehouse: + * Patrick Caulfield: Checking conninits for correctness & sending of error + * responses. + * Steve Whitehouse: Added backlog congestion level return codes. + * Patrick Caulfield: + * Steve Whitehouse: Added flow control support (outbound) + * Steve Whitehouse: Prepare for nonlinear skbs + */ + +/****************************************************************************** + (c) 1995-1998 E.M. Serrat emserrat@geocities.com + + 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 + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. +*******************************************************************************/ + +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/socket.h> +#include <linux/in.h> +#include <linux/kernel.h> +#include <linux/timer.h> +#include <linux/string.h> +#include <linux/sockios.h> +#include <linux/net.h> +#include <linux/netdevice.h> +#include <linux/inet.h> +#include <linux/route.h> +#include <linux/slab.h> +#include <net/sock.h> +#include <net/tcp_states.h> +#include <linux/fcntl.h> +#include <linux/mm.h> +#include <linux/termios.h> +#include <linux/interrupt.h> +#include <linux/proc_fs.h> +#include <linux/stat.h> +#include <linux/init.h> +#include <linux/poll.h> +#include <linux/netfilter_decnet.h> +#include <net/neighbour.h> +#include <net/dst.h> +#include <net/dn.h> +#include <net/dn_nsp.h> +#include <net/dn_dev.h> +#include <net/dn_route.h> + +extern int decnet_log_martians; + +static void dn_log_martian(struct sk_buff *skb, const char *msg) +{ + if (decnet_log_martians) { + char *devname = skb->dev ? skb->dev->name : "???"; + struct dn_skb_cb *cb = DN_SKB_CB(skb); + net_info_ratelimited("DECnet: Martian packet (%s) dev=%s src=0x%04hx dst=0x%04hx srcport=0x%04hx dstport=0x%04hx\n", + msg, devname, + le16_to_cpu(cb->src), + le16_to_cpu(cb->dst), + le16_to_cpu(cb->src_port), + le16_to_cpu(cb->dst_port)); + } +} + +/* + * For this function we've flipped the cross-subchannel bit + * if the message is an otherdata or linkservice message. Thus + * we can use it to work out what to update. + */ +static void dn_ack(struct sock *sk, struct sk_buff *skb, unsigned short ack) +{ + struct dn_scp *scp = DN_SK(sk); + unsigned short type = ((ack >> 12) & 0x0003); + int wakeup = 0; + + switch (type) { + case 0: /* ACK - Data */ + if (dn_after(ack, scp->ackrcv_dat)) { + scp->ackrcv_dat = ack & 0x0fff; + wakeup |= dn_nsp_check_xmit_queue(sk, skb, + &scp->data_xmit_queue, + ack); + } + break; + case 1: /* NAK - Data */ + break; + case 2: /* ACK - OtherData */ + if (dn_after(ack, scp->ackrcv_oth)) { + scp->ackrcv_oth = ack & 0x0fff; + wakeup |= dn_nsp_check_xmit_queue(sk, skb, + &scp->other_xmit_queue, + ack); + } + break; + case 3: /* NAK - OtherData */ + break; + } + + if (wakeup && !sock_flag(sk, SOCK_DEAD)) + sk->sk_state_change(sk); +} + +/* + * This function is a universal ack processor. + */ +static int dn_process_ack(struct sock *sk, struct sk_buff *skb, int oth) +{ + __le16 *ptr = (__le16 *)skb->data; + int len = 0; + unsigned short ack; + + if (skb->len < 2) + return len; + + if ((ack = le16_to_cpu(*ptr)) & 0x8000) { + skb_pull(skb, 2); + ptr++; + len += 2; + if ((ack & 0x4000) == 0) { + if (oth) + ack ^= 0x2000; + dn_ack(sk, skb, ack); + } + } + + if (skb->len < 2) + return len; + + if ((ack = le16_to_cpu(*ptr)) & 0x8000) { + skb_pull(skb, 2); + len += 2; + if ((ack & 0x4000) == 0) { + if (oth) + ack ^= 0x2000; + dn_ack(sk, skb, ack); + } + } + + return len; +} + + +/** + * dn_check_idf - Check an image data field format is correct. + * @pptr: Pointer to pointer to image data + * @len: Pointer to length of image data + * @max: The maximum allowed length of the data in the image data field + * @follow_on: Check that this many bytes exist beyond the end of the image data + * + * Returns: 0 if ok, -1 on error + */ +static inline int dn_check_idf(unsigned char **pptr, int *len, unsigned char max, unsigned char follow_on) +{ + unsigned char *ptr = *pptr; + unsigned char flen = *ptr++; + + (*len)--; + if (flen > max) + return -1; + if ((flen + follow_on) > *len) + return -1; + + *len -= flen; + *pptr = ptr + flen; + return 0; +} + +/* + * Table of reason codes to pass back to node which sent us a badly + * formed message, plus text messages for the log. A zero entry in + * the reason field means "don't reply" otherwise a disc init is sent with + * the specified reason code. + */ +static struct { + unsigned short reason; + const char *text; +} ci_err_table[] = { + { 0, "CI: Truncated message" }, + { NSP_REASON_ID, "CI: Destination username error" }, + { NSP_REASON_ID, "CI: Destination username type" }, + { NSP_REASON_US, "CI: Source username error" }, + { 0, "CI: Truncated at menuver" }, + { 0, "CI: Truncated before access or user data" }, + { NSP_REASON_IO, "CI: Access data format error" }, + { NSP_REASON_IO, "CI: User data format error" } +}; + +/* + * This function uses a slightly different lookup method + * to find its sockets, since it searches on object name/number + * rather than port numbers. Various tests are done to ensure that + * the incoming data is in the correct format before it is queued to + * a socket. + */ +static struct sock *dn_find_listener(struct sk_buff *skb, unsigned short *reason) +{ + struct dn_skb_cb *cb = DN_SKB_CB(skb); + struct nsp_conn_init_msg *msg = (struct nsp_conn_init_msg *)skb->data; + struct sockaddr_dn dstaddr; + struct sockaddr_dn srcaddr; + unsigned char type = 0; + int dstlen; + int srclen; + unsigned char *ptr; + int len; + int err = 0; + unsigned char menuver; + + memset(&dstaddr, 0, sizeof(struct sockaddr_dn)); + memset(&srcaddr, 0, sizeof(struct sockaddr_dn)); + + /* + * 1. Decode & remove message header + */ + cb->src_port = msg->srcaddr; + cb->dst_port = msg->dstaddr; + cb->services = msg->services; + cb->info = msg->info; + cb->segsize = le16_to_cpu(msg->segsize); + + if (!pskb_may_pull(skb, sizeof(*msg))) + goto err_out; + + skb_pull(skb, sizeof(*msg)); + + len = skb->len; + ptr = skb->data; + + /* + * 2. Check destination end username format + */ + dstlen = dn_username2sockaddr(ptr, len, &dstaddr, &type); + err++; + if (dstlen < 0) + goto err_out; + + err++; + if (type > 1) + goto err_out; + + len -= dstlen; + ptr += dstlen; + + /* + * 3. Check source end username format + */ + srclen = dn_username2sockaddr(ptr, len, &srcaddr, &type); + err++; + if (srclen < 0) + goto err_out; + + len -= srclen; + ptr += srclen; + err++; + if (len < 1) + goto err_out; + + menuver = *ptr; + ptr++; + len--; + + /* + * 4. Check that optional data actually exists if menuver says it does + */ + err++; + if ((menuver & (DN_MENUVER_ACC | DN_MENUVER_USR)) && (len < 1)) + goto err_out; + + /* + * 5. Check optional access data format + */ + err++; + if (menuver & DN_MENUVER_ACC) { + if (dn_check_idf(&ptr, &len, 39, 1)) + goto err_out; + if (dn_check_idf(&ptr, &len, 39, 1)) + goto err_out; + if (dn_check_idf(&ptr, &len, 39, (menuver & DN_MENUVER_USR) ? 1 : 0)) + goto err_out; + } + + /* + * 6. Check optional user data format + */ + err++; + if (menuver & DN_MENUVER_USR) { + if (dn_check_idf(&ptr, &len, 16, 0)) + goto err_out; + } + + /* + * 7. Look up socket based on destination end username + */ + return dn_sklist_find_listener(&dstaddr); +err_out: + dn_log_martian(skb, ci_err_table[err].text); + *reason = ci_err_table[err].reason; + return NULL; +} + + +static void dn_nsp_conn_init(struct sock *sk, struct sk_buff *skb) +{ + if (sk_acceptq_is_full(sk)) { + kfree_skb(skb); + return; + } + + sk->sk_ack_backlog++; + skb_queue_tail(&sk->sk_receive_queue, skb); + sk->sk_state_change(sk); +} + +static void dn_nsp_conn_conf(struct sock *sk, struct sk_buff *skb) +{ + struct dn_skb_cb *cb = DN_SKB_CB(skb); + struct dn_scp *scp = DN_SK(sk); + unsigned char *ptr; + + if (skb->len < 4) + goto out; + + ptr = skb->data; + cb->services = *ptr++; + cb->info = *ptr++; + cb->segsize = le16_to_cpu(*(__le16 *)ptr); + + if ((scp->state == DN_CI) || (scp->state == DN_CD)) { + scp->persist = 0; + scp->addrrem = cb->src_port; + sk->sk_state = TCP_ESTABLISHED; + scp->state = DN_RUN; + scp->services_rem = cb->services; + scp->info_rem = cb->info; + scp->segsize_rem = cb->segsize; + + if ((scp->services_rem & NSP_FC_MASK) == NSP_FC_NONE) + scp->max_window = decnet_no_fc_max_cwnd; + + if (skb->len > 0) { + u16 dlen = *skb->data; + if ((dlen <= 16) && (dlen <= skb->len)) { + scp->conndata_in.opt_optl = cpu_to_le16(dlen); + skb_copy_from_linear_data_offset(skb, 1, + scp->conndata_in.opt_data, dlen); + } + } + dn_nsp_send_link(sk, DN_NOCHANGE, 0); + if (!sock_flag(sk, SOCK_DEAD)) + sk->sk_state_change(sk); + } + +out: + kfree_skb(skb); +} + +static void dn_nsp_conn_ack(struct sock *sk, struct sk_buff *skb) +{ + struct dn_scp *scp = DN_SK(sk); + + if (scp->state == DN_CI) { + scp->state = DN_CD; + scp->persist = 0; + } + + kfree_skb(skb); +} + +static void dn_nsp_disc_init(struct sock *sk, struct sk_buff *skb) +{ + struct dn_scp *scp = DN_SK(sk); + struct dn_skb_cb *cb = DN_SKB_CB(skb); + unsigned short reason; + + if (skb->len < 2) + goto out; + + reason = le16_to_cpu(*(__le16 *)skb->data); + skb_pull(skb, 2); + + scp->discdata_in.opt_status = cpu_to_le16(reason); + scp->discdata_in.opt_optl = 0; + memset(scp->discdata_in.opt_data, 0, 16); + + if (skb->len > 0) { + u16 dlen = *skb->data; + if ((dlen <= 16) && (dlen <= skb->len)) { + scp->discdata_in.opt_optl = cpu_to_le16(dlen); + skb_copy_from_linear_data_offset(skb, 1, scp->discdata_in.opt_data, dlen); + } + } + + scp->addrrem = cb->src_port; + sk->sk_state = TCP_CLOSE; + + switch (scp->state) { + case DN_CI: + case DN_CD: + scp->state = DN_RJ; + sk->sk_err = ECONNREFUSED; + break; + case DN_RUN: + sk->sk_shutdown |= SHUTDOWN_MASK; + scp->state = DN_DN; + break; + case DN_DI: + scp->state = DN_DIC; + break; + } + + if (!sock_flag(sk, SOCK_DEAD)) { + if (sk->sk_socket->state != SS_UNCONNECTED) + sk->sk_socket->state = SS_DISCONNECTING; + sk->sk_state_change(sk); + } + + /* + * It appears that its possible for remote machines to send disc + * init messages with no port identifier if we are in the CI and + * possibly also the CD state. Obviously we shouldn't reply with + * a message if we don't know what the end point is. + */ + if (scp->addrrem) { + dn_nsp_send_disc(sk, NSP_DISCCONF, NSP_REASON_DC, GFP_ATOMIC); + } + scp->persist_fxn = dn_destroy_timer; + scp->persist = dn_nsp_persist(sk); + +out: + kfree_skb(skb); +} + +/* + * disc_conf messages are also called no_resources or no_link + * messages depending upon the "reason" field. + */ +static void dn_nsp_disc_conf(struct sock *sk, struct sk_buff *skb) +{ + struct dn_scp *scp = DN_SK(sk); + unsigned short reason; + + if (skb->len != 2) + goto out; + + reason = le16_to_cpu(*(__le16 *)skb->data); + + sk->sk_state = TCP_CLOSE; + + switch (scp->state) { + case DN_CI: + scp->state = DN_NR; + break; + case DN_DR: + if (reason == NSP_REASON_DC) + scp->state = DN_DRC; + if (reason == NSP_REASON_NL) + scp->state = DN_CN; + break; + case DN_DI: + scp->state = DN_DIC; + break; + case DN_RUN: + sk->sk_shutdown |= SHUTDOWN_MASK; + case DN_CC: + scp->state = DN_CN; + } + + if (!sock_flag(sk, SOCK_DEAD)) { + if (sk->sk_socket->state != SS_UNCONNECTED) + sk->sk_socket->state = SS_DISCONNECTING; + sk->sk_state_change(sk); + } + + scp->persist_fxn = dn_destroy_timer; + scp->persist = dn_nsp_persist(sk); + +out: + kfree_skb(skb); +} + +static void dn_nsp_linkservice(struct sock *sk, struct sk_buff *skb) +{ + struct dn_scp *scp = DN_SK(sk); + unsigned short segnum; + unsigned char lsflags; + signed char fcval; + int wake_up = 0; + char *ptr = skb->data; + unsigned char fctype = scp->services_rem & NSP_FC_MASK; + + if (skb->len != 4) + goto out; + + segnum = le16_to_cpu(*(__le16 *)ptr); + ptr += 2; + lsflags = *(unsigned char *)ptr++; + fcval = *ptr; + + /* + * Here we ignore erronous packets which should really + * should cause a connection abort. It is not critical + * for now though. + */ + if (lsflags & 0xf8) + goto out; + + if (seq_next(scp->numoth_rcv, segnum)) { + seq_add(&scp->numoth_rcv, 1); + switch(lsflags & 0x04) { /* FCVAL INT */ + case 0x00: /* Normal Request */ + switch(lsflags & 0x03) { /* FCVAL MOD */ + case 0x00: /* Request count */ + if (fcval < 0) { + unsigned char p_fcval = -fcval; + if ((scp->flowrem_dat > p_fcval) && + (fctype == NSP_FC_SCMC)) { + scp->flowrem_dat -= p_fcval; + } + } else if (fcval > 0) { + scp->flowrem_dat += fcval; + wake_up = 1; + } + break; + case 0x01: /* Stop outgoing data */ + scp->flowrem_sw = DN_DONTSEND; + break; + case 0x02: /* Ok to start again */ + scp->flowrem_sw = DN_SEND; + dn_nsp_output(sk); + wake_up = 1; + } + break; + case 0x04: /* Interrupt Request */ + if (fcval > 0) { + scp->flowrem_oth += fcval; + wake_up = 1; + } + break; + } + if (wake_up && !sock_flag(sk, SOCK_DEAD)) + sk->sk_state_change(sk); + } + + dn_nsp_send_oth_ack(sk); + +out: + kfree_skb(skb); +} + +/* + * Copy of sock_queue_rcv_skb (from sock.h) without + * bh_lock_sock() (its already held when this is called) which + * also allows data and other data to be queued to a socket. + */ +static __inline__ int dn_queue_skb(struct sock *sk, struct sk_buff *skb, int sig, struct sk_buff_head *queue) +{ + int err; + + /* Cast skb->rcvbuf to unsigned... It's pointless, but reduces + number of warnings when compiling with -W --ANK + */ + if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >= + (unsigned int)sk->sk_rcvbuf) { + err = -ENOMEM; + goto out; + } + + err = sk_filter(sk, skb); + if (err) + goto out; + + skb_set_owner_r(skb, sk); + skb_queue_tail(queue, skb); + + if (!sock_flag(sk, SOCK_DEAD)) + sk->sk_data_ready(sk); +out: + return err; +} + +static void dn_nsp_otherdata(struct sock *sk, struct sk_buff *skb) +{ + struct dn_scp *scp = DN_SK(sk); + unsigned short segnum; + struct dn_skb_cb *cb = DN_SKB_CB(skb); + int queued = 0; + + if (skb->len < 2) + goto out; + + cb->segnum = segnum = le16_to_cpu(*(__le16 *)skb->data); + skb_pull(skb, 2); + + if (seq_next(scp->numoth_rcv, segnum)) { + + if (dn_queue_skb(sk, skb, SIGURG, &scp->other_receive_queue) == 0) { + seq_add(&scp->numoth_rcv, 1); + scp->other_report = 0; + queued = 1; + } + } + + dn_nsp_send_oth_ack(sk); +out: + if (!queued) + kfree_skb(skb); +} + +static void dn_nsp_data(struct sock *sk, struct sk_buff *skb) +{ + int queued = 0; + unsigned short segnum; + struct dn_skb_cb *cb = DN_SKB_CB(skb); + struct dn_scp *scp = DN_SK(sk); + + if (skb->len < 2) + goto out; + + cb->segnum = segnum = le16_to_cpu(*(__le16 *)skb->data); + skb_pull(skb, 2); + + if (seq_next(scp->numdat_rcv, segnum)) { + if (dn_queue_skb(sk, skb, SIGIO, &sk->sk_receive_queue) == 0) { + seq_add(&scp->numdat_rcv, 1); + queued = 1; + } + + if ((scp->flowloc_sw == DN_SEND) && dn_congested(sk)) { + scp->flowloc_sw = DN_DONTSEND; + dn_nsp_send_link(sk, DN_DONTSEND, 0); + } + } + + dn_nsp_send_data_ack(sk); +out: + if (!queued) + kfree_skb(skb); +} + +/* + * If one of our conninit messages is returned, this function + * deals with it. It puts the socket into the NO_COMMUNICATION + * state. + */ +static void dn_returned_conn_init(struct sock *sk, struct sk_buff *skb) +{ + struct dn_scp *scp = DN_SK(sk); + + if (scp->state == DN_CI) { + scp->state = DN_NC; + sk->sk_state = TCP_CLOSE; + if (!sock_flag(sk, SOCK_DEAD)) + sk->sk_state_change(sk); + } + + kfree_skb(skb); +} + +static int dn_nsp_no_socket(struct sk_buff *skb, unsigned short reason) +{ + struct dn_skb_cb *cb = DN_SKB_CB(skb); + int ret = NET_RX_DROP; + + /* Must not reply to returned packets */ + if (cb->rt_flags & DN_RT_F_RTS) + goto out; + + if ((reason != NSP_REASON_OK) && ((cb->nsp_flags & 0x0c) == 0x08)) { + switch (cb->nsp_flags & 0x70) { + case 0x10: + case 0x60: /* (Retransmitted) Connect Init */ + dn_nsp_return_disc(skb, NSP_DISCINIT, reason); + ret = NET_RX_SUCCESS; + break; + case 0x20: /* Connect Confirm */ + dn_nsp_return_disc(skb, NSP_DISCCONF, reason); + ret = NET_RX_SUCCESS; + break; + } + } + +out: + kfree_skb(skb); + return ret; +} + +static int dn_nsp_rx_packet(struct sock *sk2, struct sk_buff *skb) +{ + struct dn_skb_cb *cb = DN_SKB_CB(skb); + struct sock *sk = NULL; + unsigned char *ptr = (unsigned char *)skb->data; + unsigned short reason = NSP_REASON_NL; + + if (!pskb_may_pull(skb, 2)) + goto free_out; + + skb_reset_transport_header(skb); + cb->nsp_flags = *ptr++; + + if (decnet_debug_level & 2) + printk(KERN_DEBUG "dn_nsp_rx: Message type 0x%02x\n", (int)cb->nsp_flags); + + if (cb->nsp_flags & 0x83) + goto free_out; + + /* + * Filter out conninits and useless packet types + */ + if ((cb->nsp_flags & 0x0c) == 0x08) { + switch (cb->nsp_flags & 0x70) { + case 0x00: /* NOP */ + case 0x70: /* Reserved */ + case 0x50: /* Reserved, Phase II node init */ + goto free_out; + case 0x10: + case 0x60: + if (unlikely(cb->rt_flags & DN_RT_F_RTS)) + goto free_out; + sk = dn_find_listener(skb, &reason); + goto got_it; + } + } + + if (!pskb_may_pull(skb, 3)) + goto free_out; + + /* + * Grab the destination address. + */ + cb->dst_port = *(__le16 *)ptr; + cb->src_port = 0; + ptr += 2; + + /* + * If not a connack, grab the source address too. + */ + if (pskb_may_pull(skb, 5)) { + cb->src_port = *(__le16 *)ptr; + ptr += 2; + skb_pull(skb, 5); + } + + /* + * Returned packets... + * Swap src & dst and look up in the normal way. + */ + if (unlikely(cb->rt_flags & DN_RT_F_RTS)) { + __le16 tmp = cb->dst_port; + cb->dst_port = cb->src_port; + cb->src_port = tmp; + tmp = cb->dst; + cb->dst = cb->src; + cb->src = tmp; + } + + /* + * Find the socket to which this skb is destined. + */ + sk = dn_find_by_skb(skb); +got_it: + if (sk != NULL) { + struct dn_scp *scp = DN_SK(sk); + + /* Reset backoff */ + scp->nsp_rxtshift = 0; + + /* + * We linearize everything except data segments here. + */ + if (cb->nsp_flags & ~0x60) { + if (unlikely(skb_linearize(skb))) + goto free_out; + } + + return sk_receive_skb(sk, skb, 0); + } + + return dn_nsp_no_socket(skb, reason); + +free_out: + kfree_skb(skb); + return NET_RX_DROP; +} + +int dn_nsp_rx(struct sk_buff *skb) +{ + return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_IN, NULL, skb, + skb->dev, NULL, + dn_nsp_rx_packet); +} + +/* + * This is the main receive routine for sockets. It is called + * from the above when the socket is not busy, and also from + * sock_release() when there is a backlog queued up. + */ +int dn_nsp_backlog_rcv(struct sock *sk, struct sk_buff *skb) +{ + struct dn_scp *scp = DN_SK(sk); + struct dn_skb_cb *cb = DN_SKB_CB(skb); + + if (cb->rt_flags & DN_RT_F_RTS) { + if (cb->nsp_flags == 0x18 || cb->nsp_flags == 0x68) + dn_returned_conn_init(sk, skb); + else + kfree_skb(skb); + return NET_RX_SUCCESS; + } + + /* + * Control packet. + */ + if ((cb->nsp_flags & 0x0c) == 0x08) { + switch (cb->nsp_flags & 0x70) { + case 0x10: + case 0x60: + dn_nsp_conn_init(sk, skb); + break; + case 0x20: + dn_nsp_conn_conf(sk, skb); + break; + case 0x30: + dn_nsp_disc_init(sk, skb); + break; + case 0x40: + dn_nsp_disc_conf(sk, skb); + break; + } + + } else if (cb->nsp_flags == 0x24) { + /* + * Special for connacks, 'cos they don't have + * ack data or ack otherdata info. + */ + dn_nsp_conn_ack(sk, skb); + } else { + int other = 1; + + /* both data and ack frames can kick a CC socket into RUN */ + if ((scp->state == DN_CC) && !sock_flag(sk, SOCK_DEAD)) { + scp->state = DN_RUN; + sk->sk_state = TCP_ESTABLISHED; + sk->sk_state_change(sk); + } + + if ((cb->nsp_flags & 0x1c) == 0) + other = 0; + if (cb->nsp_flags == 0x04) + other = 0; + + /* + * Read out ack data here, this applies equally + * to data, other data, link serivce and both + * ack data and ack otherdata. + */ + dn_process_ack(sk, skb, other); + + /* + * If we've some sort of data here then call a + * suitable routine for dealing with it, otherwise + * the packet is an ack and can be discarded. + */ + if ((cb->nsp_flags & 0x0c) == 0) { + + if (scp->state != DN_RUN) + goto free_out; + + switch (cb->nsp_flags) { + case 0x10: /* LS */ + dn_nsp_linkservice(sk, skb); + break; + case 0x30: /* OD */ + dn_nsp_otherdata(sk, skb); + break; + default: + dn_nsp_data(sk, skb); + } + + } else { /* Ack, chuck it out here */ +free_out: + kfree_skb(skb); + } + } + + return NET_RX_SUCCESS; +} + |