patty/src/sock.c

#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <patty/ax25.h>

patty_ax25_sock *patty_ax25_sock_new(enum patty_ax25_sock_type type) {
    patty_ax25_sock *sock;

    if ((sock = malloc(sizeof(*sock))) == NULL) {
        goto error_malloc_sock;
    }

    memset(sock, '\0', sizeof(*sock));

    sock->status   = PATTY_AX25_SOCK_CLOSED;
    sock->mode     = PATTY_AX25_SOCK_DM;
    sock->type     = type;
    sock->n_maxlen = PATTY_AX25_FRAME_DEFAULT_MAXLEN;
    sock->n_window = PATTY_AX25_FRAME_DEFAULT_WINDOW;

    return sock;

error_malloc_sock:
    return NULL;
}

void patty_ax25_sock_destroy(patty_ax25_sock *sock) {
    free(sock);
}

static size_t copy_addr_to_buf(patty_ax25_sock *sock, uint8_t *buf, size_t offset) {
    size_t i;

    memcpy(&buf[offset], &sock->remote, sizeof(patty_ax25_addr));
    offset += sizeof(patty_ax25_addr);
    buf[offset-1] &= ~1;

    memcpy(&buf[offset], &sock->local,  sizeof(patty_ax25_addr));
    offset += sizeof(patty_ax25_addr);
    buf[offset-1] &= ~1;

    for (i=0; i<sock->hops; i++) {
        memcpy(&buf[offset], &sock->repeaters[i], sizeof(patty_ax25_addr));
        offset += sizeof(patty_ax25_addr);
    }

    buf[offset - 1] |= 0x01;

    return offset;
}

int patty_ax25_sock_send_sabm(patty_ax25_sock *sock) {
    size_t offset = 0;
    uint8_t *buf = (uint8_t *)(sock->iface->tx_buf);
    
    offset = copy_addr_to_buf(sock, buf, offset);

    buf[offset++] = 0x3f;
    buf[offset++] = PATTY_AX25_PROTO_NONE;

    return patty_ax25_if_send(sock->iface,
                              buf,
                              offset);
}