diff options
Diffstat (limited to 'net/rose/rose_subr.c')
-rw-r--r-- | net/rose/rose_subr.c | 556 |
1 files changed, 556 insertions, 0 deletions
diff --git a/net/rose/rose_subr.c b/net/rose/rose_subr.c new file mode 100644 index 000000000..4dbc437a9 --- /dev/null +++ b/net/rose/rose_subr.c @@ -0,0 +1,556 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * + * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) + */ +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/socket.h> +#include <linux/in.h> +#include <linux/kernel.h> +#include <linux/timer.h> +#include <linux/string.h> +#include <linux/sockios.h> +#include <linux/net.h> +#include <linux/slab.h> +#include <net/ax25.h> +#include <linux/inet.h> +#include <linux/netdevice.h> +#include <linux/skbuff.h> +#include <net/sock.h> +#include <net/tcp_states.h> +#include <linux/fcntl.h> +#include <linux/mm.h> +#include <linux/interrupt.h> +#include <net/rose.h> + +static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose); + +/* + * This routine purges all of the queues of frames. + */ +void rose_clear_queues(struct sock *sk) +{ + skb_queue_purge(&sk->sk_write_queue); + skb_queue_purge(&rose_sk(sk)->ack_queue); +} + +/* + * This routine purges the input queue of those frames that have been + * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the + * SDL diagram. + */ +void rose_frames_acked(struct sock *sk, unsigned short nr) +{ + struct sk_buff *skb; + struct rose_sock *rose = rose_sk(sk); + + /* + * Remove all the ack-ed frames from the ack queue. + */ + if (rose->va != nr) { + while (skb_peek(&rose->ack_queue) != NULL && rose->va != nr) { + skb = skb_dequeue(&rose->ack_queue); + kfree_skb(skb); + rose->va = (rose->va + 1) % ROSE_MODULUS; + } + } +} + +void rose_requeue_frames(struct sock *sk) +{ + struct sk_buff *skb, *skb_prev = NULL; + + /* + * Requeue all the un-ack-ed frames on the output queue to be picked + * up by rose_kick. This arrangement handles the possibility of an + * empty output queue. + */ + while ((skb = skb_dequeue(&rose_sk(sk)->ack_queue)) != NULL) { + if (skb_prev == NULL) + skb_queue_head(&sk->sk_write_queue, skb); + else + skb_append(skb_prev, skb, &sk->sk_write_queue); + skb_prev = skb; + } +} + +/* + * Validate that the value of nr is between va and vs. Return true or + * false for testing. + */ +int rose_validate_nr(struct sock *sk, unsigned short nr) +{ + struct rose_sock *rose = rose_sk(sk); + unsigned short vc = rose->va; + + while (vc != rose->vs) { + if (nr == vc) return 1; + vc = (vc + 1) % ROSE_MODULUS; + } + + return nr == rose->vs; +} + +/* + * This routine is called when the packet layer internally generates a + * control frame. + */ +void rose_write_internal(struct sock *sk, int frametype) +{ + struct rose_sock *rose = rose_sk(sk); + struct sk_buff *skb; + unsigned char *dptr; + unsigned char lci1, lci2; + int maxfaclen = 0; + int len, faclen; + int reserve; + + reserve = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + 1; + len = ROSE_MIN_LEN; + + switch (frametype) { + case ROSE_CALL_REQUEST: + len += 1 + ROSE_ADDR_LEN + ROSE_ADDR_LEN; + maxfaclen = 256; + break; + case ROSE_CALL_ACCEPTED: + case ROSE_CLEAR_REQUEST: + case ROSE_RESET_REQUEST: + len += 2; + break; + } + + skb = alloc_skb(reserve + len + maxfaclen, GFP_ATOMIC); + if (!skb) + return; + + /* + * Space for AX.25 header and PID. + */ + skb_reserve(skb, reserve); + + dptr = skb_put(skb, len); + + lci1 = (rose->lci >> 8) & 0x0F; + lci2 = (rose->lci >> 0) & 0xFF; + + switch (frametype) { + case ROSE_CALL_REQUEST: + *dptr++ = ROSE_GFI | lci1; + *dptr++ = lci2; + *dptr++ = frametype; + *dptr++ = ROSE_CALL_REQ_ADDR_LEN_VAL; + memcpy(dptr, &rose->dest_addr, ROSE_ADDR_LEN); + dptr += ROSE_ADDR_LEN; + memcpy(dptr, &rose->source_addr, ROSE_ADDR_LEN); + dptr += ROSE_ADDR_LEN; + faclen = rose_create_facilities(dptr, rose); + skb_put(skb, faclen); + dptr += faclen; + break; + + case ROSE_CALL_ACCEPTED: + *dptr++ = ROSE_GFI | lci1; + *dptr++ = lci2; + *dptr++ = frametype; + *dptr++ = 0x00; /* Address length */ + *dptr++ = 0; /* Facilities length */ + break; + + case ROSE_CLEAR_REQUEST: + *dptr++ = ROSE_GFI | lci1; + *dptr++ = lci2; + *dptr++ = frametype; + *dptr++ = rose->cause; + *dptr++ = rose->diagnostic; + break; + + case ROSE_RESET_REQUEST: + *dptr++ = ROSE_GFI | lci1; + *dptr++ = lci2; + *dptr++ = frametype; + *dptr++ = ROSE_DTE_ORIGINATED; + *dptr++ = 0; + break; + + case ROSE_RR: + case ROSE_RNR: + *dptr++ = ROSE_GFI | lci1; + *dptr++ = lci2; + *dptr = frametype; + *dptr++ |= (rose->vr << 5) & 0xE0; + break; + + case ROSE_CLEAR_CONFIRMATION: + case ROSE_RESET_CONFIRMATION: + *dptr++ = ROSE_GFI | lci1; + *dptr++ = lci2; + *dptr++ = frametype; + break; + + default: + printk(KERN_ERR "ROSE: rose_write_internal - invalid frametype %02X\n", frametype); + kfree_skb(skb); + return; + } + + rose_transmit_link(skb, rose->neighbour); +} + +int rose_decode(struct sk_buff *skb, int *ns, int *nr, int *q, int *d, int *m) +{ + unsigned char *frame; + + frame = skb->data; + + *ns = *nr = *q = *d = *m = 0; + + switch (frame[2]) { + case ROSE_CALL_REQUEST: + case ROSE_CALL_ACCEPTED: + case ROSE_CLEAR_REQUEST: + case ROSE_CLEAR_CONFIRMATION: + case ROSE_RESET_REQUEST: + case ROSE_RESET_CONFIRMATION: + return frame[2]; + default: + break; + } + + if ((frame[2] & 0x1F) == ROSE_RR || + (frame[2] & 0x1F) == ROSE_RNR) { + *nr = (frame[2] >> 5) & 0x07; + return frame[2] & 0x1F; + } + + if ((frame[2] & 0x01) == ROSE_DATA) { + *q = (frame[0] & ROSE_Q_BIT) == ROSE_Q_BIT; + *d = (frame[0] & ROSE_D_BIT) == ROSE_D_BIT; + *m = (frame[2] & ROSE_M_BIT) == ROSE_M_BIT; + *nr = (frame[2] >> 5) & 0x07; + *ns = (frame[2] >> 1) & 0x07; + return ROSE_DATA; + } + + return ROSE_ILLEGAL; +} + +static int rose_parse_national(unsigned char *p, struct rose_facilities_struct *facilities, int len) +{ + unsigned char *pt; + unsigned char l, lg, n = 0; + int fac_national_digis_received = 0; + + do { + switch (*p & 0xC0) { + case 0x00: + if (len < 2) + return -1; + p += 2; + n += 2; + len -= 2; + break; + + case 0x40: + if (len < 3) + return -1; + if (*p == FAC_NATIONAL_RAND) + facilities->rand = ((p[1] << 8) & 0xFF00) + ((p[2] << 0) & 0x00FF); + p += 3; + n += 3; + len -= 3; + break; + + case 0x80: + if (len < 4) + return -1; + p += 4; + n += 4; + len -= 4; + break; + + case 0xC0: + if (len < 2) + return -1; + l = p[1]; + if (len < 2 + l) + return -1; + if (*p == FAC_NATIONAL_DEST_DIGI) { + if (!fac_national_digis_received) { + if (l < AX25_ADDR_LEN) + return -1; + memcpy(&facilities->source_digis[0], p + 2, AX25_ADDR_LEN); + facilities->source_ndigis = 1; + } + } + else if (*p == FAC_NATIONAL_SRC_DIGI) { + if (!fac_national_digis_received) { + if (l < AX25_ADDR_LEN) + return -1; + memcpy(&facilities->dest_digis[0], p + 2, AX25_ADDR_LEN); + facilities->dest_ndigis = 1; + } + } + else if (*p == FAC_NATIONAL_FAIL_CALL) { + if (l < AX25_ADDR_LEN) + return -1; + memcpy(&facilities->fail_call, p + 2, AX25_ADDR_LEN); + } + else if (*p == FAC_NATIONAL_FAIL_ADD) { + if (l < 1 + ROSE_ADDR_LEN) + return -1; + memcpy(&facilities->fail_addr, p + 3, ROSE_ADDR_LEN); + } + else if (*p == FAC_NATIONAL_DIGIS) { + if (l % AX25_ADDR_LEN) + return -1; + fac_national_digis_received = 1; + facilities->source_ndigis = 0; + facilities->dest_ndigis = 0; + for (pt = p + 2, lg = 0 ; lg < l ; pt += AX25_ADDR_LEN, lg += AX25_ADDR_LEN) { + if (pt[6] & AX25_HBIT) { + if (facilities->dest_ndigis >= ROSE_MAX_DIGIS) + return -1; + memcpy(&facilities->dest_digis[facilities->dest_ndigis++], pt, AX25_ADDR_LEN); + } else { + if (facilities->source_ndigis >= ROSE_MAX_DIGIS) + return -1; + memcpy(&facilities->source_digis[facilities->source_ndigis++], pt, AX25_ADDR_LEN); + } + } + } + p += l + 2; + n += l + 2; + len -= l + 2; + break; + } + } while (*p != 0x00 && len > 0); + + return n; +} + +static int rose_parse_ccitt(unsigned char *p, struct rose_facilities_struct *facilities, int len) +{ + unsigned char l, n = 0; + char callsign[11]; + + do { + switch (*p & 0xC0) { + case 0x00: + if (len < 2) + return -1; + p += 2; + n += 2; + len -= 2; + break; + + case 0x40: + if (len < 3) + return -1; + p += 3; + n += 3; + len -= 3; + break; + + case 0x80: + if (len < 4) + return -1; + p += 4; + n += 4; + len -= 4; + break; + + case 0xC0: + if (len < 2) + return -1; + l = p[1]; + + /* Prevent overflows*/ + if (l < 10 || l > 20) + return -1; + + if (*p == FAC_CCITT_DEST_NSAP) { + memcpy(&facilities->source_addr, p + 7, ROSE_ADDR_LEN); + memcpy(callsign, p + 12, l - 10); + callsign[l - 10] = '\0'; + asc2ax(&facilities->source_call, callsign); + } + if (*p == FAC_CCITT_SRC_NSAP) { + memcpy(&facilities->dest_addr, p + 7, ROSE_ADDR_LEN); + memcpy(callsign, p + 12, l - 10); + callsign[l - 10] = '\0'; + asc2ax(&facilities->dest_call, callsign); + } + p += l + 2; + n += l + 2; + len -= l + 2; + break; + } + } while (*p != 0x00 && len > 0); + + return n; +} + +int rose_parse_facilities(unsigned char *p, unsigned packet_len, + struct rose_facilities_struct *facilities) +{ + int facilities_len, len; + + facilities_len = *p++; + + if (facilities_len == 0 || (unsigned int)facilities_len > packet_len) + return 0; + + while (facilities_len >= 3 && *p == 0x00) { + facilities_len--; + p++; + + switch (*p) { + case FAC_NATIONAL: /* National */ + len = rose_parse_national(p + 1, facilities, facilities_len - 1); + break; + + case FAC_CCITT: /* CCITT */ + len = rose_parse_ccitt(p + 1, facilities, facilities_len - 1); + break; + + default: + printk(KERN_DEBUG "ROSE: rose_parse_facilities - unknown facilities family %02X\n", *p); + len = 1; + break; + } + + if (len < 0) + return 0; + if (WARN_ON(len >= facilities_len)) + return 0; + facilities_len -= len + 1; + p += len + 1; + } + + return facilities_len == 0; +} + +static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose) +{ + unsigned char *p = buffer + 1; + char *callsign; + char buf[11]; + int len, nb; + + /* National Facilities */ + if (rose->rand != 0 || rose->source_ndigis == 1 || rose->dest_ndigis == 1) { + *p++ = 0x00; + *p++ = FAC_NATIONAL; + + if (rose->rand != 0) { + *p++ = FAC_NATIONAL_RAND; + *p++ = (rose->rand >> 8) & 0xFF; + *p++ = (rose->rand >> 0) & 0xFF; + } + + /* Sent before older facilities */ + if ((rose->source_ndigis > 0) || (rose->dest_ndigis > 0)) { + int maxdigi = 0; + *p++ = FAC_NATIONAL_DIGIS; + *p++ = AX25_ADDR_LEN * (rose->source_ndigis + rose->dest_ndigis); + for (nb = 0 ; nb < rose->source_ndigis ; nb++) { + if (++maxdigi >= ROSE_MAX_DIGIS) + break; + memcpy(p, &rose->source_digis[nb], AX25_ADDR_LEN); + p[6] |= AX25_HBIT; + p += AX25_ADDR_LEN; + } + for (nb = 0 ; nb < rose->dest_ndigis ; nb++) { + if (++maxdigi >= ROSE_MAX_DIGIS) + break; + memcpy(p, &rose->dest_digis[nb], AX25_ADDR_LEN); + p[6] &= ~AX25_HBIT; + p += AX25_ADDR_LEN; + } + } + + /* For compatibility */ + if (rose->source_ndigis > 0) { + *p++ = FAC_NATIONAL_SRC_DIGI; + *p++ = AX25_ADDR_LEN; + memcpy(p, &rose->source_digis[0], AX25_ADDR_LEN); + p += AX25_ADDR_LEN; + } + + /* For compatibility */ + if (rose->dest_ndigis > 0) { + *p++ = FAC_NATIONAL_DEST_DIGI; + *p++ = AX25_ADDR_LEN; + memcpy(p, &rose->dest_digis[0], AX25_ADDR_LEN); + p += AX25_ADDR_LEN; + } + } + + *p++ = 0x00; + *p++ = FAC_CCITT; + + *p++ = FAC_CCITT_DEST_NSAP; + + callsign = ax2asc(buf, &rose->dest_call); + + *p++ = strlen(callsign) + 10; + *p++ = (strlen(callsign) + 9) * 2; /* ??? */ + + *p++ = 0x47; *p++ = 0x00; *p++ = 0x11; + *p++ = ROSE_ADDR_LEN * 2; + memcpy(p, &rose->dest_addr, ROSE_ADDR_LEN); + p += ROSE_ADDR_LEN; + + memcpy(p, callsign, strlen(callsign)); + p += strlen(callsign); + + *p++ = FAC_CCITT_SRC_NSAP; + + callsign = ax2asc(buf, &rose->source_call); + + *p++ = strlen(callsign) + 10; + *p++ = (strlen(callsign) + 9) * 2; /* ??? */ + + *p++ = 0x47; *p++ = 0x00; *p++ = 0x11; + *p++ = ROSE_ADDR_LEN * 2; + memcpy(p, &rose->source_addr, ROSE_ADDR_LEN); + p += ROSE_ADDR_LEN; + + memcpy(p, callsign, strlen(callsign)); + p += strlen(callsign); + + len = p - buffer; + buffer[0] = len - 1; + + return len; +} + +void rose_disconnect(struct sock *sk, int reason, int cause, int diagnostic) +{ + struct rose_sock *rose = rose_sk(sk); + + rose_stop_timer(sk); + rose_stop_idletimer(sk); + + rose_clear_queues(sk); + + rose->lci = 0; + rose->state = ROSE_STATE_0; + + if (cause != -1) + rose->cause = cause; + + if (diagnostic != -1) + rose->diagnostic = diagnostic; + + sk->sk_state = TCP_CLOSE; + sk->sk_err = reason; + sk->sk_shutdown |= SEND_SHUTDOWN; + + if (!sock_flag(sk, SOCK_DEAD)) { + sk->sk_state_change(sk); + sock_set_flag(sk, SOCK_DEAD); + } +} |