^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * X.25 Packet Layer release 002
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * This is ALPHA test software. This code may break your machine, randomly fail to work with new
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * releases, misbehave and/or generally screw up. It might even work.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * This code REQUIRES 2.1.15 or higher
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * History
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * X.25 001 Jonathan Naylor Started coding.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * 2000-09-04 Henner Eisen Prevent freeing a dangling skb.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #define pr_fmt(fmt) "X25: " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/netdevice.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/skbuff.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <net/sock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <linux/if_arp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <net/x25.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <net/x25device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) static int x25_receive_data(struct sk_buff *skb, struct x25_neigh *nb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) struct sock *sk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) unsigned short frametype;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) unsigned int lci;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) if (!pskb_may_pull(skb, X25_STD_MIN_LEN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) frametype = skb->data[2];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) * LCI of zero is always for us, and its always a link control
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) * frame.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) if (lci == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) x25_link_control(skb, nb, frametype);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) * Find an existing socket.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) if ((sk = x25_find_socket(lci, nb)) != NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) int queued = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) skb_reset_transport_header(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) bh_lock_sock(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) if (!sock_owned_by_user(sk)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) queued = x25_process_rx_frame(sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) queued = !sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) bh_unlock_sock(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) sock_put(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) return queued;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) * Is is a Call Request ? if so process it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) if (frametype == X25_CALL_REQUEST)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) return x25_rx_call_request(skb, nb, lci);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) * Its not a Call Request, nor is it a control frame.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) * Can we forward it?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) if (x25_forward_data(lci, nb, skb)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) if (frametype == X25_CLEAR_CONFIRMATION) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) x25_clear_forward_by_lci(lci);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) x25_transmit_clear_request(nb, lci, 0x0D);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) if (frametype != X25_CLEAR_CONFIRMATION)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) pr_debug("x25_receive_data(): unknown frame type %2x\n",frametype);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) int x25_lapb_receive_frame(struct sk_buff *skb, struct net_device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) struct packet_type *ptype, struct net_device *orig_dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) struct sk_buff *nskb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) struct x25_neigh *nb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) if (!net_eq(dev_net(dev), &init_net))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) goto drop;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) nskb = skb_copy(skb, GFP_ATOMIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) if (!nskb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) goto drop;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) skb = nskb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) * Packet received from unrecognised device, throw it away.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) nb = x25_get_neigh(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) if (!nb) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) pr_debug("unknown neighbour - %s\n", dev->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) goto drop;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) if (!pskb_may_pull(skb, 1)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) x25_neigh_put(nb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) switch (skb->data[0]) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) case X25_IFACE_DATA:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) skb_pull(skb, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) if (x25_receive_data(skb, nb)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) x25_neigh_put(nb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) case X25_IFACE_CONNECT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) x25_link_established(nb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) case X25_IFACE_DISCONNECT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) x25_link_terminated(nb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) x25_neigh_put(nb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) drop:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) void x25_establish_link(struct x25_neigh *nb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) struct sk_buff *skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) unsigned char *ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) switch (nb->dev->type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) case ARPHRD_X25:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) pr_err("x25_dev: out of memory\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) ptr = skb_put(skb, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) *ptr = X25_IFACE_CONNECT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) #if IS_ENABLED(CONFIG_LLC)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) case ARPHRD_ETHER:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) skb->protocol = htons(ETH_P_X25);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) skb->dev = nb->dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) dev_queue_xmit(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) void x25_terminate_link(struct x25_neigh *nb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) struct sk_buff *skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) unsigned char *ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) #if IS_ENABLED(CONFIG_LLC)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) if (nb->dev->type == ARPHRD_ETHER)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) if (nb->dev->type != ARPHRD_X25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) skb = alloc_skb(1, GFP_ATOMIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) if (!skb) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) pr_err("x25_dev: out of memory\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) ptr = skb_put(skb, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) *ptr = X25_IFACE_DISCONNECT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) skb->protocol = htons(ETH_P_X25);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) skb->dev = nb->dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) dev_queue_xmit(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) void x25_send_frame(struct sk_buff *skb, struct x25_neigh *nb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) unsigned char *dptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) skb_reset_network_header(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) switch (nb->dev->type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) case ARPHRD_X25:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) dptr = skb_push(skb, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) *dptr = X25_IFACE_DATA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) #if IS_ENABLED(CONFIG_LLC)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) case ARPHRD_ETHER:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) skb->protocol = htons(ETH_P_X25);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) skb->dev = nb->dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) dev_queue_xmit(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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