1/* SPDX-License-Identifier: GPL-2.0-or-later */
  2#ifndef _NET_DN_NSP_H
  3#define _NET_DN_NSP_H
  4/******************************************************************************
  5    (c) 1995-1998 E.M. Serrat		emserrat@geocities.com
  6    
  7*******************************************************************************/
  8/* dn_nsp.c functions prototyping */
  9
 10void dn_nsp_send_data_ack(struct sock *sk);
 11void dn_nsp_send_oth_ack(struct sock *sk);
 12void dn_send_conn_ack(struct sock *sk);
 13void dn_send_conn_conf(struct sock *sk, gfp_t gfp);
 14void dn_nsp_send_disc(struct sock *sk, unsigned char type,
 15		      unsigned short reason, gfp_t gfp);
 16void dn_nsp_return_disc(struct sk_buff *skb, unsigned char type,
 17			unsigned short reason);
 18void dn_nsp_send_link(struct sock *sk, unsigned char lsflags, char fcval);
 19void dn_nsp_send_conninit(struct sock *sk, unsigned char flags);
 20
 21void dn_nsp_output(struct sock *sk);
 22int dn_nsp_check_xmit_queue(struct sock *sk, struct sk_buff *skb,
 23			    struct sk_buff_head *q, unsigned short acknum);
 24void dn_nsp_queue_xmit(struct sock *sk, struct sk_buff *skb, gfp_t gfp,
 25		       int oob);
 26unsigned long dn_nsp_persist(struct sock *sk);
 27int dn_nsp_xmit_timeout(struct sock *sk);
 28
 29int dn_nsp_rx(struct sk_buff *);
 30int dn_nsp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
 31
 32struct sk_buff *dn_alloc_skb(struct sock *sk, int size, gfp_t pri);
 33struct sk_buff *dn_alloc_send_skb(struct sock *sk, size_t *size, int noblock,
 34				  long timeo, int *err);
 35
 36#define NSP_REASON_OK 0		/* No error */
 37#define NSP_REASON_NR 1		/* No resources */
 38#define NSP_REASON_UN 2		/* Unrecognised node name */
 39#define NSP_REASON_SD 3		/* Node shutting down */
 40#define NSP_REASON_ID 4		/* Invalid destination end user */
 41#define NSP_REASON_ER 5		/* End user lacks resources */
 42#define NSP_REASON_OB 6		/* Object too busy */
 43#define NSP_REASON_US 7		/* Unspecified error */
 44#define NSP_REASON_TP 8		/* Third-Party abort */
 45#define NSP_REASON_EA 9		/* End user has aborted the link */
 46#define NSP_REASON_IF 10	/* Invalid node name format */
 47#define NSP_REASON_LS 11	/* Local node shutdown */
 48#define NSP_REASON_LL 32	/* Node lacks logical-link resources */
 49#define NSP_REASON_LE 33	/* End user lacks logical-link resources */
 50#define NSP_REASON_UR 34	/* Unacceptable RQSTRID or PASSWORD field */
 51#define NSP_REASON_UA 36	/* Unacceptable ACCOUNT field */
 52#define NSP_REASON_TM 38	/* End user timed out logical link */
 53#define NSP_REASON_NU 39	/* Node unreachable */
 54#define NSP_REASON_NL 41	/* No-link message */
 55#define NSP_REASON_DC 42	/* Disconnect confirm */
 56#define NSP_REASON_IO 43	/* Image data field overflow */
 57
 58#define NSP_DISCINIT 0x38
 59#define NSP_DISCCONF 0x48
 60
 61/*------------------------- NSP - messages ------------------------------*/
 62/* Data Messages */
 63/*---------------*/
 64
 65/* Data Messages    (data segment/interrupt/link service)               */
 66
 67struct nsp_data_seg_msg {
 68	__u8   msgflg;
 69	__le16 dstaddr;
 70	__le16 srcaddr;
 71} __packed;
 72
 73struct nsp_data_opt_msg {
 74	__le16 acknum;
 75	__le16 segnum;
 76	__le16 lsflgs;
 77} __packed;
 78
 79struct nsp_data_opt_msg1 {
 80	__le16 acknum;
 81	__le16 segnum;
 82} __packed;
 83
 84
 85/* Acknowledgment Message (data/other data)                             */
 86struct nsp_data_ack_msg {
 87	__u8   msgflg;
 88	__le16 dstaddr;
 89	__le16 srcaddr;
 90	__le16 acknum;
 91} __packed;
 92
 93/* Connect Acknowledgment Message */
 94struct  nsp_conn_ack_msg {
 95	__u8 msgflg;
 96	__le16 dstaddr;
 97} __packed;
 98
 99
100/* Connect Initiate/Retransmit Initiate/Connect Confirm */
101struct  nsp_conn_init_msg {
102	__u8   msgflg;
103#define NSP_CI      0x18            /* Connect Initiate     */
104#define NSP_RCI     0x68            /* Retrans. Conn Init   */
105	__le16 dstaddr;
106	__le16 srcaddr;
107	__u8   services;
108#define NSP_FC_NONE   0x00            /* Flow Control None    */
109#define NSP_FC_SRC    0x04            /* Seg Req. Count       */
110#define NSP_FC_SCMC   0x08            /* Sess. Control Mess   */
111#define NSP_FC_MASK   0x0c            /* FC type mask         */
112	__u8   info;
113	__le16 segsize;
114} __packed;
115
116/* Disconnect Initiate/Disconnect Confirm */
117struct  nsp_disconn_init_msg {
118	__u8   msgflg;
119	__le16 dstaddr;
120	__le16 srcaddr;
121	__le16 reason;
122} __packed;
123
124
125
126struct  srcobj_fmt {
127	__u8   format;
128	__u8   task;
129	__le16 grpcode;
130	__le16 usrcode;
131	__u8   dlen;
132} __packed;
133
134/*
135 * A collection of functions for manipulating the sequence
136 * numbers used in NSP. Similar in operation to the functions
137 * of the same name in TCP.
138 */
139static __inline__ int dn_before(__u16 seq1, __u16 seq2)
140{
141        seq1 &= 0x0fff;
142        seq2 &= 0x0fff;
143
144        return (int)((seq1 - seq2) & 0x0fff) > 2048;
145}
146
147
148static __inline__ int dn_after(__u16 seq1, __u16 seq2)
149{
150        seq1 &= 0x0fff;
151        seq2 &= 0x0fff;
152
153        return (int)((seq2 - seq1) & 0x0fff) > 2048;
154}
155
156static __inline__ int dn_equal(__u16 seq1, __u16 seq2)
157{
158        return ((seq1 ^ seq2) & 0x0fff) == 0;
159}
160
161static __inline__ int dn_before_or_equal(__u16 seq1, __u16 seq2)
162{
163	return (dn_before(seq1, seq2) || dn_equal(seq1, seq2));
164}
165
166static __inline__ void seq_add(__u16 *seq, __u16 off)
167{
168        (*seq) += off;
169        (*seq) &= 0x0fff;
170}
171
172static __inline__ int seq_next(__u16 seq1, __u16 seq2)
173{
174	return dn_equal(seq1 + 1, seq2);
175}
176
177/*
178 * Can we delay the ack ?
179 */
180static __inline__ int sendack(__u16 seq)
181{
182        return (int)((seq & 0x1000) ? 0 : 1);
183}
184
185/*
186 * Is socket congested ?
187 */
188static __inline__ int dn_congested(struct sock *sk)
189{
190        return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1);
191}
192
193#define DN_MAX_NSP_DATA_HEADER (11)
194
195#endif /* _NET_DN_NSP_H */