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 2a24b243b8..e17d84a55d 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; /* @@ -844,20 +849,11 @@ int x25_rx_call_request(struct sk_buff *skb, struct x25_neigh *nb, len = skb->data[0] + 1; 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 183fea3bba..c349bbd616 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 v1.2.2 From ebc3f64b864fc16a594c2e63bf55a55c7d42084b Mon Sep 17 00:00:00 2001 From: Shaun Pereira Date: Wed, 22 Jun 2005 22:16:17 -0700 Subject: [X25]: Fast select with no restriction on response This patch is a follow up to patch 1 regarding "Selective Sub Address matching with call user data". It allows use of the Fast-Select-Acceptance optional user facility for X.25. This patch just implements fast select with no restriction on response (NRR). What this means (according to ITU-T Recomendation 10/96 section 6.16) is that if in an incoming call packet, the relevant facility bits are set for fast-select-NRR, then the called DTE can issue a direct response to the incoming packet using a call-accepted packet that contains call-user-data. This patch allows such a response. The called DTE can also respond with a clear-request packet that contains call-user-data. However, this feature is currently not implemented by the patch. How is Fast Select Acceptance used? By default, the system does not allow fast select acceptance (as before). To enable a response to fast select acceptance, After a listen socket in created and bound as follows socket(AF_X25, SOCK_SEQPACKET, 0); bind(call_soc, (struct sockaddr *)&locl_addr, sizeof(locl_addr)); but before a listen system call is made, the following ioctl should be used. ioctl(call_soc,SIOCX25CALLACCPTAPPRV); Now the listen system call can be made listen(call_soc, 4); After this, an incoming-call packet will be accepted, but no call-accepted packet will be sent back until the following system call is made on the socket that accepts the call ioctl(vc_soc,SIOCX25SENDCALLACCPT); The network (or cisco xot router used for testing here) will allow the application server's call-user-data in the call-accepted packet, provided the call-request was made with Fast-select NRR. Signed-off-by: Shaun Pereira Signed-off-by: Andrew Morton Signed-off-by: David S. Miller --- net/x25/af_x25.c | 37 +++++++++++++++++++++++++++++++++---- net/x25/x25_facilities.c | 34 +++++++++++++++++++++++++++++----- net/x25/x25_subr.c | 23 ++++++++++++++++++----- 3 files changed, 80 insertions(+), 14 deletions(-) (limited to 'net/x25') diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c index e17d84a55d..04bec047fa 100644 --- a/net/x25/af_x25.c +++ b/net/x25/af_x25.c @@ -31,6 +31,8 @@ * x25_proc.c, using seq_file * 2005-04-02 Shaun Pereira Selective sub address matching * with call user data + * 2005-04-15 Shaun Pereira Fast select with no restriction on + * response */ #include @@ -502,6 +504,8 @@ static int x25_create(struct socket *sock, int protocol) x25->t2 = sysctl_x25_ack_holdback_timeout; x25->state = X25_STATE_0; x25->cudmatchlength = 0; + x25->accptapprv = X25_DENY_ACCPT_APPRV; /* normally no cud */ + /* on call accept */ x25->facilities.winsize_in = X25_DEFAULT_WINDOW_SIZE; x25->facilities.winsize_out = X25_DEFAULT_WINDOW_SIZE; @@ -551,6 +555,7 @@ static struct sock *x25_make_new(struct sock *osk) x25->facilities = ox25->facilities; x25->qbitincl = ox25->qbitincl; x25->cudmatchlength = ox25->cudmatchlength; + x25->accptapprv = ox25->accptapprv; x25_init_timers(sk); out: @@ -900,9 +905,11 @@ int x25_rx_call_request(struct sk_buff *skb, struct x25_neigh *nb, 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; + /* Normally all calls are accepted immediatly */ + if(makex25->accptapprv & X25_DENY_ACCPT_APPRV) { + x25_write_internal(make, X25_CALL_ACCEPTED); + makex25->state = X25_STATE_3; + } /* * Incoming Call User Data. @@ -1294,7 +1301,8 @@ static int x25_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) if (facilities.throughput < 0x03 || facilities.throughput > 0xDD) break; - if (facilities.reverse && facilities.reverse != 1) + if (facilities.reverse && + (facilities.reverse | 0x81)!= 0x81) break; x25->facilities = facilities; rc = 0; @@ -1348,6 +1356,27 @@ static int x25_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) break; } + case SIOCX25CALLACCPTAPPRV: { + rc = -EINVAL; + if (sk->sk_state != TCP_CLOSE) + break; + x25->accptapprv = X25_ALLOW_ACCPT_APPRV; + rc = 0; + break; + } + + case SIOCX25SENDCALLACCPT: { + rc = -EINVAL; + if (sk->sk_state != TCP_ESTABLISHED) + break; + if (x25->accptapprv) /* must call accptapprv above */ + break; + x25_write_internal(sk, X25_CALL_ACCEPTED); + x25->state = X25_STATE_3; + rc = 0; + break; + } + default: rc = dev_ioctl(cmd, argp); break; diff --git a/net/x25/x25_facilities.c b/net/x25/x25_facilities.c index a21bdb95f9..54278b962f 100644 --- a/net/x25/x25_facilities.c +++ b/net/x25/x25_facilities.c @@ -17,6 +17,8 @@ * X.25 001 Split from x25_subr.c * mar/20/00 Daniela Squassoni Disabling/enabling of facilities * negotiation. + * apr/14/05 Shaun Pereira - Allow fast select with no restriction + * on response. */ #include @@ -43,9 +45,31 @@ int x25_parse_facilities(struct sk_buff *skb, case X25_FAC_CLASS_A: switch (*p) { case X25_FAC_REVERSE: - facilities->reverse = p[1] & 0x01; - *vc_fac_mask |= X25_MASK_REVERSE; - break; + if((p[1] & 0x81) == 0x81) { + facilities->reverse = p[1] & 0x81; + *vc_fac_mask |= X25_MASK_REVERSE; + break; + } + + if((p[1] & 0x01) == 0x01) { + facilities->reverse = p[1] & 0x01; + *vc_fac_mask |= X25_MASK_REVERSE; + break; + } + + if((p[1] & 0x80) == 0x80) { + facilities->reverse = p[1] & 0x80; + *vc_fac_mask |= X25_MASK_REVERSE; + break; + } + + if(p[1] == 0x00) { + facilities->reverse + = X25_DEFAULT_REVERSE; + *vc_fac_mask |= X25_MASK_REVERSE; + break; + } + case X25_FAC_THROUGHPUT: facilities->throughput = p[1]; *vc_fac_mask |= X25_MASK_THROUGHPUT; @@ -122,7 +146,7 @@ int x25_create_facilities(unsigned char *buffer, if (facilities->reverse && (facil_mask & X25_MASK_REVERSE)) { *p++ = X25_FAC_REVERSE; - *p++ = !!facilities->reverse; + *p++ = facilities->reverse; } if (facilities->throughput && (facil_mask & X25_MASK_THROUGHPUT)) { @@ -171,7 +195,7 @@ int x25_negotiate_facilities(struct sk_buff *skb, struct sock *sk, /* * They want reverse charging, we won't accept it. */ - if (theirs.reverse && ours->reverse) { + if ((theirs.reverse & 0x01 ) && (ours->reverse & 0x01)) { SOCK_DEBUG(sk, "X.25: rejecting reverse charging request"); return -1; } diff --git a/net/x25/x25_subr.c b/net/x25/x25_subr.c index c349bbd616..7fd872ad0c 100644 --- a/net/x25/x25_subr.c +++ b/net/x25/x25_subr.c @@ -19,6 +19,8 @@ * mar/20/00 Daniela Squassoni Disabling/enabling of facilities * negotiation. * jun/24/01 Arnaldo C. Melo use skb_queue_purge, cleanups + * apr/04/15 Shaun Pereira Fast select with no + * restriction on response. */ #include @@ -127,8 +129,12 @@ void x25_write_internal(struct sock *sk, int frametype) len += 1 + X25_ADDR_LEN + X25_MAX_FAC_LEN + X25_MAX_CUD_LEN; break; - case X25_CALL_ACCEPTED: - len += 1 + X25_MAX_FAC_LEN + X25_MAX_CUD_LEN; + case X25_CALL_ACCEPTED: /* fast sel with no restr on resp */ + if(x25->facilities.reverse & 0x80) { + len += 1 + X25_MAX_FAC_LEN + X25_MAX_CUD_LEN; + } else { + len += 1 + X25_MAX_FAC_LEN; + } break; case X25_CLEAR_REQUEST: case X25_RESET_REQUEST: @@ -203,9 +209,16 @@ void x25_write_internal(struct sock *sk, int frametype) x25->vc_facil_mask); dptr = skb_put(skb, len); memcpy(dptr, facilities, len); - dptr = skb_put(skb, x25->calluserdata.cudlength); - memcpy(dptr, x25->calluserdata.cuddata, - x25->calluserdata.cudlength); + + /* fast select with no restriction on response + allows call user data. Userland must + ensure it is ours and not theirs */ + if(x25->facilities.reverse & 0x80) { + dptr = skb_put(skb, + x25->calluserdata.cudlength); + memcpy(dptr, x25->calluserdata.cuddata, + x25->calluserdata.cudlength); + } x25->calluserdata.cudlength = 0; break; -- cgit v1.2.2