From cb65d506c34c86df5bcef939ce5a8666a451bd8b Mon Sep 17 00:00:00 2001 From: Shaun Pereira Date: Wed, 22 Jun 2005 22:15:01 -0700 Subject: [X25]: Selective sub-address matching with call user data. From: Shaun Pereira This is the first (independent of the second) patch of two that I am working on with x25 on linux (tested with xot on a cisco router). Details are as follows. Current state of module: A server using the current implementation (2.6.11.7) of the x25 module will accept a call request/ incoming call packet at the listening x.25 address, from all callers to that address, as long as NO call user data is present in the packet header. If the server needs to choose to accept a particular call request/ incoming call packet arriving at its listening x25 address, then the kernel has to allow a match of call user data present in the call request packet with its own. This is required when multiple servers listen at the same x25 address and device interface. The kernel currently matches ALL call user data, if present. Current Changes: This patch is a follow up to the patch submitted previously by Andrew Hendry, and allows the user to selectively control the number of octets of call user data in the call request packet, that the kernel will match. By default no call user data is matched, even if call user data is present. To allow call user data matching, a cudmatchlength > 0 has to be passed into the kernel after which the passed number of octets will be matched. Otherwise the kernel behavior is exactly as the original implementation. This patch also ensures that as is normally the case, no call user data will be present in the Call accepted / call connected packet sent back to the caller Future Changes on next patch: There are cases however when call user data may be present in the call accepted packet. According to the X.25 recommendation (ITU-T 10/96) section 5.2.3.2 call user data may be present in the call accepted packet provided the fast select facility is used. My next patch will include this fast select utility and the ability to send up to 128 octets call user data in the call accepted packet provided the fast select facility is used. I am currently testing this, again with xot on linux and cisco. Signed-off-by: Shaun Pereira (With a fix from Alexey Dobriyan ) Signed-off-by: Andrew Morton Signed-off-by: David S. Miller --- net/x25/af_x25.c | 73 +++++++++++++++++++++++++++++++++++------------------- net/x25/x25_subr.c | 18 -------------- 2 files changed, 48 insertions(+), 43 deletions(-) (limited to 'net/x25') diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c index 2a24b24..e17d84a 100644 --- a/net/x25/af_x25.c +++ b/net/x25/af_x25.c @@ -29,6 +29,8 @@ * 2000-11-14 Henner Eisen Closing datalink from NETDEV_GOING_DOWN * 2002-10-06 Arnaldo C. Melo Get rid of cli/sti, move proc stuff to * x25_proc.c, using seq_file + * 2005-04-02 Shaun Pereira Selective sub address matching + * with call user data */ #include @@ -219,7 +221,8 @@ static void x25_insert_socket(struct sock *sk) * Note: if a listening socket has cud set it must only get calls * with matching cud. */ -static struct sock *x25_find_listener(struct x25_address *addr, struct x25_calluserdata *calluserdata) +static struct sock *x25_find_listener(struct x25_address *addr, + struct sk_buff *skb) { struct sock *s; struct sock *next_best; @@ -230,22 +233,23 @@ static struct sock *x25_find_listener(struct x25_address *addr, struct x25_callu sk_for_each(s, node, &x25_list) if ((!strcmp(addr->x25_addr, - x25_sk(s)->source_addr.x25_addr) || - !strcmp(addr->x25_addr, - null_x25_address.x25_addr)) && - s->sk_state == TCP_LISTEN) { - + x25_sk(s)->source_addr.x25_addr) || + !strcmp(addr->x25_addr, + null_x25_address.x25_addr)) && + s->sk_state == TCP_LISTEN) { /* * Found a listening socket, now check the incoming * call user data vs this sockets call user data */ - if (x25_check_calluserdata(&x25_sk(s)->calluserdata, calluserdata)) { - sock_hold(s); - goto found; - } - if (x25_sk(s)->calluserdata.cudlength == 0) { + if(skb->len > 0 && x25_sk(s)->cudmatchlength > 0) { + if((memcmp(x25_sk(s)->calluserdata.cuddata, + skb->data, + x25_sk(s)->cudmatchlength)) == 0) { + sock_hold(s); + goto found; + } + } else next_best = s; - } } if (next_best) { s = next_best; @@ -497,6 +501,7 @@ static int x25_create(struct socket *sock, int protocol) x25->t23 = sysctl_x25_clear_request_timeout; x25->t2 = sysctl_x25_ack_holdback_timeout; x25->state = X25_STATE_0; + x25->cudmatchlength = 0; x25->facilities.winsize_in = X25_DEFAULT_WINDOW_SIZE; x25->facilities.winsize_out = X25_DEFAULT_WINDOW_SIZE; @@ -545,6 +550,7 @@ static struct sock *x25_make_new(struct sock *osk) x25->t2 = ox25->t2; x25->facilities = ox25->facilities; x25->qbitincl = ox25->qbitincl; + x25->cudmatchlength = ox25->cudmatchlength; x25_init_timers(sk); out: @@ -822,7 +828,6 @@ int x25_rx_call_request(struct sk_buff *skb, struct x25_neigh *nb, struct x25_sock *makex25; struct x25_address source_addr, dest_addr; struct x25_facilities facilities; - struct x25_calluserdata calluserdata; int len, rc; /* @@ -845,19 +850,10 @@ int x25_rx_call_request(struct sk_buff *skb, struct x25_neigh *nb, skb_pull(skb,len); /* - * Incoming Call User Data. - */ - if (skb->len >= 0) { - memcpy(calluserdata.cuddata, skb->data, skb->len); - calluserdata.cudlength = skb->len; - } - - skb_push(skb,len); - - /* * Find a listener for the particular address/cud pair. */ - sk = x25_find_listener(&source_addr,&calluserdata); + sk = x25_find_listener(&source_addr,skb); + skb_push(skb,len); /* * We can't accept the Call Request. @@ -900,12 +896,22 @@ int x25_rx_call_request(struct sk_buff *skb, struct x25_neigh *nb, makex25->neighbour = nb; makex25->facilities = facilities; makex25->vc_facil_mask = x25_sk(sk)->vc_facil_mask; - makex25->calluserdata = calluserdata; + /* ensure no reverse facil on accept */ + makex25->vc_facil_mask &= ~X25_MASK_REVERSE; + makex25->cudmatchlength = x25_sk(sk)->cudmatchlength; x25_write_internal(make, X25_CALL_ACCEPTED); makex25->state = X25_STATE_3; + /* + * Incoming Call User Data. + */ + if (skb->len >= 0) { + memcpy(makex25->calluserdata.cuddata, skb->data, skb->len); + makex25->calluserdata.cudlength = skb->len; + } + sk->sk_ack_backlog++; x25_insert_socket(make); @@ -1325,6 +1331,23 @@ static int x25_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) break; } + case SIOCX25SCUDMATCHLEN: { + struct x25_subaddr sub_addr; + rc = -EINVAL; + if(sk->sk_state != TCP_CLOSE) + break; + rc = -EFAULT; + if (copy_from_user(&sub_addr, argp, + sizeof(sub_addr))) + break; + rc = -EINVAL; + if(sub_addr.cudmatchlength > X25_MAX_CUD_LEN) + break; + x25->cudmatchlength = sub_addr.cudmatchlength; + rc = 0; + break; + } + default: rc = dev_ioctl(cmd, argp); break; diff --git a/net/x25/x25_subr.c b/net/x25/x25_subr.c index 183fea3..c349bbd 100644 --- a/net/x25/x25_subr.c +++ b/net/x25/x25_subr.c @@ -354,21 +354,3 @@ void x25_check_rbuf(struct sock *sk) } } -/* - * Compare 2 calluserdata structures, used to find correct listening sockets - * when call user data is used. - */ -int x25_check_calluserdata(struct x25_calluserdata *ours, struct x25_calluserdata *theirs) -{ - int i; - if (ours->cudlength != theirs->cudlength) - return 0; - - for (i=0;icudlength;i++) { - if (ours->cuddata[i] != theirs->cuddata[i]) { - return 0; - } - } - return 1; -} - -- cgit v1.1