diff options
Diffstat (limited to 'ax25ipd/bpqether.c')
| -rw-r--r-- | ax25ipd/bpqether.c | 342 |
1 files changed, 342 insertions, 0 deletions
diff --git a/ax25ipd/bpqether.c b/ax25ipd/bpqether.c new file mode 100644 index 0000000..58333f1 --- /dev/null +++ b/ax25ipd/bpqether.c @@ -0,0 +1,342 @@ +/* @(#) $Id: bpqether.c,v 1.1 2005/10/30 10:31:40 dl9sau Exp $ */ + +extern int ttyfd; +/* + * this is a port of wampes ethertap whith my extension for bpqether + * + * (c) 20020630 Thomas Osterried dl9sau + * License: GPL + */ + +#include <sys/types.h> + +#include <errno.h> +#include <fcntl.h> +#include <stdio.h> +#include <sys/ioctl.h> +#include <sys/socket.h> +#include <sys/stat.h> +#include <unistd.h> +#include <syslog.h> + +#ifdef linux + +#include <linux/version.h> +#ifndef KERNEL_VERSION +#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c)) +#endif +#ifndef LINUX_VERSION_CODE +#define LINUX_VERSION_CODE KERNEL_VERSION(2,4,0)-1 +#endif + +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0) +#define TRY_TUNTAP 1 +#include <net/if.h> +#include <linux/if_tun.h> +#else +#include <linux/if.h> +#endif + +#endif /* linux */ + +#include "ax25ipd.h" + +#define ETAP_MTU_MIN 256 +#define ETAP_MTU 1024 +#define ETAP_MTU_MAX 1500 +#ifndef MAX_FRAME +#define MAX_FRAME 2048 +#endif + +#define ETHERTAP_HEADER_LEN_TUN 18 +#define ETHERTAP_HEADER_LEN_ETHERTAP 16 +#define ETHERTAP_HEADER_LEN_MAX ETHERTAP_HEADER_LEN_TUN + +struct ethertap_packet { + char ethernet_header[18]; + char data[MAX_FRAME]; +}; + +unsigned char hwaddr_remote[6]; + +static int ethertap_header_len; + +/*---------------------------------------------------------------------------*/ + +int send_bpq(unsigned char *buf, int l) +{ + struct ethertap_packet ethertap_packet; + void *addr = ðertap_packet; + int offset = ETHERTAP_HEADER_LEN_MAX - ethertap_header_len; + + static const unsigned char ethernet_header[18] = { + 0x00, 0x00, 0x00, 0x02, /* ??? ??? ETH_P_AX25 (16bit) */ + 0xfe, 0xfd, 0x00, 0x00, 0x00, 0x00, /* Destination address (kernel et +hertap module) */ + 0xfe, 0xfe, 0x00, 0x00, 0x00, 0x00, /* Source address (WAMPES etherta +p module) */ + 0x08, 0xff /* Protocol (bpqether) */ + }; + + if (l <= 0) + return -1; + + if (l > (sizeof(ethertap_packet.data) - 2)) + l = sizeof(ethertap_packet.data); + memcpy(ethertap_packet.data + 2, buf, l); + memcpy(ethertap_packet.ethernet_header, (const char *) ethernet_header, sizeof(ethernet_header)); + memcpy(ethertap_packet.ethernet_header + 4, hwaddr_remote, 6); + memcpy(ethertap_packet.ethernet_header + 4 + 6 + 2, hwaddr_remote +2, 6 -2); + ethertap_packet.data[0] = (l + 5) % 256; + ethertap_packet.data[1] = (l + 5) / 256; + l += 2; + + //send_tty(addr + offset, l + sizeof(ethertap_packet.ethernet_header) - offset); + write(ttyfd, addr + offset, l + sizeof(ethertap_packet.ethernet_header) - offset); + return l; +} + +/*---------------------------------------------------------------------------*/ + +int receive_bpq(unsigned char *buf, int l) +{ + if ((l -= ethertap_header_len) <= 0 || + buf[ethertap_header_len-2] & 0xff != 0x08 || + buf[ethertap_header_len-1] & 0xff != 0xff) { + // not a bpqether packet. + // drop silently - ethernet.ax25 is not the only protocol spokenon ethernet ;) + return -1; + } + l -= 2; + if (l <= 0 && buf[ethertap_header_len] + buf[ethertap_header_len] * 256 - 5 != l) { + // length error in bpqether packet + return 0; + } + + from_kiss(buf + ethertap_header_len + 2, l); + return l; +} + +/*---------------------------------------------------------------------------*/ +/* TUN/TAP support for linux. ethertap is obsolete */ + +#ifdef TRY_TUNTAP +static int tun_alloc(char *dev) +{ + struct ifreq ifr; + int fd, err; + + if ((fd = open("/dev/net/tun", O_RDWR)) < 0) + return -1; + + memset(&ifr, 0, sizeof(ifr)); + + /* Flags: IFF_TUN - TUN device (no Ethernet headers) + * IFF_TAP - TAP device + * + * IFF_NO_PI - Do not provide packet information + */ + ifr.ifr_flags = IFF_TAP; + if (*dev) { + strncpy(ifr.ifr_name, dev, IFNAMSIZ); + ifr.ifr_name[IFNAMSIZ-1] = 0; + } + + if ((err = ioctl(fd, TUNSETIFF, (void *) &ifr)) < 0 ) { + close(fd); + return err; + } + strcpy(dev, ifr.ifr_name); + + /* persist mode */ + //if (ioctl(fd, TUNSETPERSIST, 1) < 0) + //perror("TUNSETPERSIST"); + + /* don't checksum */ + //if (ioctl(fd, TUNSETNOCSUM, 1) < 0) + //perror("TUNSETNOCSUM"); + + return fd; +} +#endif + +/*---------------------------------------------------------------------------*/ + +int open_ethertap(char *ifname) +{ + + int fd; + char devname[PATH_MAX]; + struct ifreq ifr; + struct stat statbuf; + int tuntap = 0; + int mtu = 0; + int skfd; + + strcpy(devname, "/dev/"); + strncpy(devname + 5, ifname, sizeof(devname) - 5 -1); + devname[sizeof(devname) -1] = 0; + + // tuntap == 0: original ethertap. works on a real character device + if (!stat(devname, &statbuf)) { + fd = open(devname, O_RDWR); + if (fd < 0) { + LOGL2("%s: %s\n", devname, strerror(errno)); + return -1; + } +#ifdef TRY_TUNTAP + } else { + strcpy(devname, ifname); + if ((fd = tun_alloc(devname)) < 0) { + LOGL2("%s: %s\n", devname, strerror(errno)); + return -1; + } + ifname = devname; + tuntap = 1; +#endif + } + ethertap_header_len = (tuntap ? ETHERTAP_HEADER_LEN_TUN : ETHERTAP_HEADER_LEN_ETHERTAP); + + if ((skfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { + perror("socket()"); + close(fd); + return -1; + } + + memset(&ifr, 0, sizeof(ifr)); + + strncpy(ifr.ifr_name, ifname, IFNAMSIZ); + ifr.ifr_name[IFNAMSIZ-1] = 0; + if (ioctl(skfd, SIOCGIFFLAGS, &ifr) < 0) + perror("SIOCGIFFLAGS"); + + ifr.ifr_flags |= (IFF_UP | IFF_NOARP); + if (ioctl(skfd, SIOCSIFFLAGS, &ifr) < 0) + perror("SIOCSIFFLAGS"); + + strncpy(ifr.ifr_name, ifname, IFNAMSIZ); + ifr.ifr_name[IFNAMSIZ-1] = 0; + if (ioctl(skfd, SIOCGIFHWADDR, &ifr) < 0) { + perror("SIOCGIFHWADDR"); + hwaddr_remote[0] = 0xfe; + hwaddr_remote[1] = 0xfd; + hwaddr_remote[2] = 0x0; + hwaddr_remote[3] = 0x0; + hwaddr_remote[4] = 0x0; + hwaddr_remote[5] = 0x0; + } else + memcpy(hwaddr_remote, ifr.ifr_hwaddr.sa_data, 6); + + if (ttyspeed > ETAP_MTU_MIN && ttyspeed != 9600) { + mtu = ttyspeed; + } else { + strncpy(ifr.ifr_name, ifname, IFNAMSIZ); + ifr.ifr_name[IFNAMSIZ-1] = 0; + strcpy(ifr.ifr_name, ifname); + if (ioctl(skfd, SIOCGIFMTU, &ifr) < 0) + perror("SIOCGIFMTU"); + else + mtu = ifr.ifr_mtu; + } + if (mtu < ETAP_MTU_MIN || mtu > ETAP_MTU_MAX) + mtu = ETAP_MTU; + strncpy(ifr.ifr_name, ifname, IFNAMSIZ); + ifr.ifr_name[IFNAMSIZ-1] = 0; + ifr.ifr_mtu = mtu; + if (ioctl(skfd, SIOCSIFMTU, &ifr) < 0) + perror("SIOSGIFMTU"); + + close(skfd); + + return fd; + +} + +/*---------------------------------------------------------------------------*/ + +int set_bpq_dev_call_and_up(char *ifname) +{ + FILE * fp; + char buf[1024]; + char bpq_name[IFNAMSIZ]; + char dev_name[IFNAMSIZ]; + struct ifreq ifr; + struct sockaddr *sa; + int drop; + int skfd; + int len; + int err = -1; + + // 1. find correspondent bpqether device in /proc (i.e. bpq0 for tap0) + // 2. set the ax25 call of bpq0 (in this example) + // 3. ifup bpq0 + + if (!(fp = fopen("/proc/net/bpqether", "r"))) { + perror("/proc/net/bpqether"); + return -1; + } + + // look up bpqether devce in /proc: + // dev ether destination accept from + // bpq0 tap0 FF:FF:FF:FF:FF:FF * + + drop = 1; + *bpq_name = *dev_name = 0; + while (fgets(buf, sizeof(buf), fp)) { + if (drop) { + // header line + drop = 0; + continue; + } + sscanf(buf, "%s %s ", bpq_name, dev_name); + if (!strcmp(dev_name, ifname)) + break; + *bpq_name = *dev_name = 0; + } + fclose(fp); + if (!*bpq_name) { + LOGL2("Did not found bpqether device for %s in /proc/net/bpqether: %s", ifr.ifr_name, strerror(errno)); + return -1; + } + + LOGL1("found bpq device %s for %s\n", bpq_name, dev_name); + + if ((skfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { + perror("socket()"); + return -1; + } + memset(&ifr, 0, sizeof(ifr)); + memcpy(ifr.ifr_name, bpq_name, IFNAMSIZ); + ifr.ifr_name[IFNAMSIZ-1] = 0; + + ifr.ifr_hwaddr.sa_family = PF_AX25; + memcpy(ifr.ifr_hwaddr.sa_data, mycallsign, 7); + + if (ioctl(skfd, SIOCSIFHWADDR, &ifr) < 0) { + perror("SIOCSIFHWADDR"); + close(skfd); + return -1; + } + strncpy(ifr.ifr_name, bpq_name, IFNAMSIZ); + ifr.ifr_name[IFNAMSIZ-1] = 0; + ifr.ifr_mtu = 256; + if (ioctl(skfd, SIOCSIFMTU, &ifr) < 0) + perror("SIOSGIFMTU"); + + strncpy(ifr.ifr_name, bpq_name, IFNAMSIZ); + ifr.ifr_name[IFNAMSIZ-1] = 0; + if (ioctl(skfd, SIOCGIFFLAGS, &ifr) < 0) { + perror("SIOCGIFFLAGS"); + ifr.ifr_flags = 0; + } + + ifr.ifr_flags |= (IFF_UP); + if (ioctl(skfd, SIOCSIFFLAGS, &ifr) < 0) { + perror("SIOCSIFFLAGS"); + err = -1; + } + + close(skfd); + + return err; +} |