From ebc3f64b864fc16a594c2e63bf55a55c7d42084b Mon Sep 17 00:00:00 2001 From: Shaun Pereira Date: Wed, 22 Jun 2005 22:16:17 -0700 Subject: [PATCH] [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 --- include/linux/x25.h | 2 ++ include/net/x25.h | 6 ++++-- net/x25/af_x25.c | 37 +++++++++++++++++++++++++++++++++---- net/x25/x25_facilities.c | 34 +++++++++++++++++++++++++++++----- net/x25/x25_subr.c | 23 ++++++++++++++++++----- 5 files changed, 86 insertions(+), 16 deletions(-) diff --git a/include/linux/x25.h b/include/linux/x25.h index 6f43b3d202..16d44931af 100644 --- a/include/linux/x25.h +++ b/include/linux/x25.h @@ -19,6 +19,8 @@ #define SIOCX25SCALLUSERDATA (SIOCPROTOPRIVATE + 5) #define SIOCX25GCAUSEDIAG (SIOCPROTOPRIVATE + 6) #define SIOCX25SCUDMATCHLEN (SIOCPROTOPRIVATE + 7) +#define SIOCX25CALLACCPTAPPRV (SIOCPROTOPRIVATE + 8) +#define SIOCX25SENDCALLACCPT (SIOCPROTOPRIVATE + 9) /* * Values for {get,set}sockopt. diff --git a/include/net/x25.h b/include/net/x25.h index 9dd70dd4a9..8b39b98876 100644 --- a/include/net/x25.h +++ b/include/net/x25.h @@ -79,6 +79,8 @@ enum { #define X25_DEFAULT_PACKET_SIZE X25_PS128 /* Default Packet Size */ #define X25_DEFAULT_THROUGHPUT 0x0A /* Deafult Throughput */ #define X25_DEFAULT_REVERSE 0x00 /* Default Reverse Charging */ +#define X25_DENY_ACCPT_APPRV 0x01 /* Default value */ +#define X25_ALLOW_ACCPT_APPRV 0x00 /* Control enabled */ #define X25_SMODULUS 8 #define X25_EMODULUS 128 @@ -94,7 +96,7 @@ enum { #define X25_FAC_CLASS_C 0x80 #define X25_FAC_CLASS_D 0xC0 -#define X25_FAC_REVERSE 0x01 +#define X25_FAC_REVERSE 0x01 /* also fast select */ #define X25_FAC_THROUGHPUT 0x02 #define X25_FAC_PACKET_SIZE 0x42 #define X25_FAC_WINDOW_SIZE 0x43 @@ -135,7 +137,7 @@ struct x25_sock { struct x25_address source_addr, dest_addr; struct x25_neigh *neighbour; unsigned int lci, cudmatchlength; - unsigned char state, condition, qbitincl, intflag; + unsigned char state, condition, qbitincl, intflag, accptapprv; unsigned short vs, vr, va, vl; unsigned long t2, t21, t22, t23; unsigned short fraglen; 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; -- 2.39.5