root/include/net/dn_nsp.h

INCLUDED FROM

DEFINITIONS

1. dn_before
2. dn_after
3. dn_equal
4. dn_before_or_equal
5. seq_add
6. seq_next
7. sendack
8. dn_congested

   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 
  10 void dn_nsp_send_data_ack(struct sock *sk);
  11 void dn_nsp_send_oth_ack(struct sock *sk);
  12 void dn_send_conn_ack(struct sock *sk);
  13 void dn_send_conn_conf(struct sock *sk, gfp_t gfp);
  14 void dn_nsp_send_disc(struct sock *sk, unsigned char type,
  15                       unsigned short reason, gfp_t gfp);
  16 void dn_nsp_return_disc(struct sk_buff *skb, unsigned char type,
  17                         unsigned short reason);
  18 void dn_nsp_send_link(struct sock *sk, unsigned char lsflags, char fcval);
  19 void dn_nsp_send_conninit(struct sock *sk, unsigned char flags);
  20 
  21 void dn_nsp_output(struct sock *sk);
  22 int dn_nsp_check_xmit_queue(struct sock *sk, struct sk_buff *skb,
  23                             struct sk_buff_head *q, unsigned short acknum);
  24 void dn_nsp_queue_xmit(struct sock *sk, struct sk_buff *skb, gfp_t gfp,
  25                        int oob);
  26 unsigned long dn_nsp_persist(struct sock *sk);
  27 int dn_nsp_xmit_timeout(struct sock *sk);
  28 
  29 int dn_nsp_rx(struct sk_buff *);
  30 int dn_nsp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
  31 
  32 struct sk_buff *dn_alloc_skb(struct sock *sk, int size, gfp_t pri);
  33 struct 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 
  67 struct nsp_data_seg_msg {
  68         __u8   msgflg;
  69         __le16 dstaddr;
  70         __le16 srcaddr;
  71 } __packed;
  72 
  73 struct nsp_data_opt_msg {
  74         __le16 acknum;
  75         __le16 segnum;
  76         __le16 lsflgs;
  77 } __packed;
  78 
  79 struct nsp_data_opt_msg1 {
  80         __le16 acknum;
  81         __le16 segnum;
  82 } __packed;
  83 
  84 
  85 /* Acknowledgment Message (data/other data)                             */
  86 struct nsp_data_ack_msg {
  87         __u8   msgflg;
  88         __le16 dstaddr;
  89         __le16 srcaddr;
  90         __le16 acknum;
  91 } __packed;
  92 
  93 /* Connect Acknowledgment Message */
  94 struct  nsp_conn_ack_msg {
  95         __u8 msgflg;
  96         __le16 dstaddr;
  97 } __packed;
  98 
  99 
 100 /* Connect Initiate/Retransmit Initiate/Connect Confirm */
 101 struct  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 */
 117 struct  nsp_disconn_init_msg {
 118         __u8   msgflg;
 119         __le16 dstaddr;
 120         __le16 srcaddr;
 121         __le16 reason;
 122 } __packed;
 123 
 124 
 125 
 126 struct  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  */
 139 static __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 
 148 static __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 
 156 static __inline__ int dn_equal(__u16 seq1, __u16 seq2)
 157 {
 158         return ((seq1 ^ seq2) & 0x0fff) == 0;
 159 }
 160 
 161 static __inline__ int dn_before_or_equal(__u16 seq1, __u16 seq2)
 162 {
 163         return (dn_before(seq1, seq2) || dn_equal(seq1, seq2));
 164 }
 165 
 166 static __inline__ void seq_add(__u16 *seq, __u16 off)
 167 {
 168         (*seq) += off;
 169         (*seq) &= 0x0fff;
 170 }
 171 
 172 static __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  */
 180 static __inline__ int sendack(__u16 seq)
 181 {
 182         return (int)((seq & 0x1000) ? 0 : 1);
 183 }
 184 
 185 /*
 186  * Is socket congested ?
 187  */
 188 static __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 */