diff options
Diffstat (limited to 'networking/libiproute/iptunnel.c')
-rw-r--r-- | networking/libiproute/iptunnel.c | 580 |
1 files changed, 580 insertions, 0 deletions
diff --git a/networking/libiproute/iptunnel.c b/networking/libiproute/iptunnel.c new file mode 100644 index 0000000..14fc6bb --- /dev/null +++ b/networking/libiproute/iptunnel.c @@ -0,0 +1,580 @@ +/* vi: set sw=4 ts=4: */ +/* + * iptunnel.c "ip tunnel" + * + * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. + * + * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> + * + * Changes: + * + * Rani Assaf <rani@magic.metawire.com> 980929: resolve addresses + * Rani Assaf <rani@magic.metawire.com> 980930: do not allow key for ipip/sit + * Phil Karn <karn@ka9q.ampr.org> 990408: "pmtudisc" flag + */ + +#include <netinet/ip.h> +#include <net/if.h> +#include <net/if_arp.h> +#include <asm/types.h> + +#ifndef __constant_htons +#define __constant_htons htons +#endif + +// FYI: #define SIOCDEVPRIVATE 0x89F0 + +/* From linux/if_tunnel.h. #including it proved troublesome + * (redefiniton errors due to name collisions in linux/ and net[inet]/) */ +#define SIOCGETTUNNEL (SIOCDEVPRIVATE + 0) +#define SIOCADDTUNNEL (SIOCDEVPRIVATE + 1) +#define SIOCDELTUNNEL (SIOCDEVPRIVATE + 2) +#define SIOCCHGTUNNEL (SIOCDEVPRIVATE + 3) +//#define SIOCGETPRL (SIOCDEVPRIVATE + 4) +//#define SIOCADDPRL (SIOCDEVPRIVATE + 5) +//#define SIOCDELPRL (SIOCDEVPRIVATE + 6) +//#define SIOCCHGPRL (SIOCDEVPRIVATE + 7) +#define GRE_CSUM __constant_htons(0x8000) +//#define GRE_ROUTING __constant_htons(0x4000) +#define GRE_KEY __constant_htons(0x2000) +#define GRE_SEQ __constant_htons(0x1000) +//#define GRE_STRICT __constant_htons(0x0800) +//#define GRE_REC __constant_htons(0x0700) +//#define GRE_FLAGS __constant_htons(0x00F8) +//#define GRE_VERSION __constant_htons(0x0007) +struct ip_tunnel_parm { + char name[IFNAMSIZ]; + int link; + uint16_t i_flags; + uint16_t o_flags; + uint32_t i_key; + uint32_t o_key; + struct iphdr iph; +}; +/* SIT-mode i_flags */ +//#define SIT_ISATAP 0x0001 +//struct ip_tunnel_prl { +// uint32_t addr; +// uint16_t flags; +// uint16_t __reserved; +// uint32_t datalen; +// uint32_t __reserved2; +// /* data follows */ +//}; +///* PRL flags */ +//#define PRL_DEFAULT 0x0001 + +#include "ip_common.h" /* #include "libbb.h" is inside */ +#include "rt_names.h" +#include "utils.h" + + +/* Dies on error */ +static int do_ioctl_get_ifindex(char *dev) +{ + struct ifreq ifr; + int fd; + + strncpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name)); + fd = xsocket(AF_INET, SOCK_DGRAM, 0); + xioctl(fd, SIOCGIFINDEX, &ifr); + close(fd); + return ifr.ifr_ifindex; +} + +static int do_ioctl_get_iftype(char *dev) +{ + struct ifreq ifr; + int fd; + int err; + + strncpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name)); + fd = xsocket(AF_INET, SOCK_DGRAM, 0); + err = ioctl_or_warn(fd, SIOCGIFHWADDR, &ifr); + close(fd); + return err ? -1 : ifr.ifr_addr.sa_family; +} + +static char *do_ioctl_get_ifname(int idx) +{ + struct ifreq ifr; + int fd; + int err; + + ifr.ifr_ifindex = idx; + fd = xsocket(AF_INET, SOCK_DGRAM, 0); + err = ioctl_or_warn(fd, SIOCGIFNAME, &ifr); + close(fd); + return err ? NULL : xstrndup(ifr.ifr_name, sizeof(ifr.ifr_name)); +} + +static int do_get_ioctl(const char *basedev, struct ip_tunnel_parm *p) +{ + struct ifreq ifr; + int fd; + int err; + + strncpy(ifr.ifr_name, basedev, sizeof(ifr.ifr_name)); + ifr.ifr_ifru.ifru_data = (void*)p; + fd = xsocket(AF_INET, SOCK_DGRAM, 0); + err = ioctl_or_warn(fd, SIOCGETTUNNEL, &ifr); + close(fd); + return err; +} + +/* Dies on error, otherwise returns 0 */ +static int do_add_ioctl(int cmd, const char *basedev, struct ip_tunnel_parm *p) +{ + struct ifreq ifr; + int fd; + + if (cmd == SIOCCHGTUNNEL && p->name[0]) { + strncpy(ifr.ifr_name, p->name, sizeof(ifr.ifr_name)); + } else { + strncpy(ifr.ifr_name, basedev, sizeof(ifr.ifr_name)); + } + ifr.ifr_ifru.ifru_data = (void*)p; + fd = xsocket(AF_INET, SOCK_DGRAM, 0); +#if ENABLE_IOCTL_HEX2STR_ERROR + /* #define magic will turn ioctl# into string */ + if (cmd == SIOCCHGTUNNEL) + xioctl(fd, SIOCCHGTUNNEL, &ifr); + else + xioctl(fd, SIOCADDTUNNEL, &ifr); +#else + xioctl(fd, cmd, &ifr); +#endif + close(fd); + return 0; +} + +/* Dies on error, otherwise returns 0 */ +static int do_del_ioctl(const char *basedev, struct ip_tunnel_parm *p) +{ + struct ifreq ifr; + int fd; + + if (p->name[0]) { + strncpy(ifr.ifr_name, p->name, sizeof(ifr.ifr_name)); + } else { + strncpy(ifr.ifr_name, basedev, sizeof(ifr.ifr_name)); + } + ifr.ifr_ifru.ifru_data = (void*)p; + fd = xsocket(AF_INET, SOCK_DGRAM, 0); + xioctl(fd, SIOCDELTUNNEL, &ifr); + close(fd); + return 0; +} + +/* Dies on error */ +static void parse_args(char **argv, int cmd, struct ip_tunnel_parm *p) +{ + static const char keywords[] ALIGN1 = + "mode\0""ipip\0""ip/ip\0""gre\0""gre/ip\0""sit\0""ipv6/ip\0" + "key\0""ikey\0""okey\0""seq\0""iseq\0""oseq\0" + "csum\0""icsum\0""ocsum\0""nopmtudisc\0""pmtudisc\0" + "remote\0""any\0""local\0""dev\0" + "ttl\0""inherit\0""tos\0""dsfield\0" + "name\0"; + enum { + ARG_mode, ARG_ipip, ARG_ip_ip, ARG_gre, ARG_gre_ip, ARG_sit, ARG_ip6_ip, + ARG_key, ARG_ikey, ARG_okey, ARG_seq, ARG_iseq, ARG_oseq, + ARG_csum, ARG_icsum, ARG_ocsum, ARG_nopmtudisc, ARG_pmtudisc, + ARG_remote, ARG_any, ARG_local, ARG_dev, + ARG_ttl, ARG_inherit, ARG_tos, ARG_dsfield, + ARG_name + }; + int count = 0; + char medium[IFNAMSIZ]; + int key; + + memset(p, 0, sizeof(*p)); + memset(&medium, 0, sizeof(medium)); + + p->iph.version = 4; + p->iph.ihl = 5; +#ifndef IP_DF +#define IP_DF 0x4000 /* Flag: "Don't Fragment" */ +#endif + p->iph.frag_off = htons(IP_DF); + + while (*argv) { + key = index_in_strings(keywords, *argv); + if (key == ARG_mode) { + NEXT_ARG(); + key = index_in_strings(keywords, *argv); + if (key == ARG_ipip || + key == ARG_ip_ip) { + if (p->iph.protocol && p->iph.protocol != IPPROTO_IPIP) { + bb_error_msg_and_die("%s tunnel mode", "you managed to ask for more than one"); + } + p->iph.protocol = IPPROTO_IPIP; + } else if (key == ARG_gre || + key == ARG_gre_ip) { + if (p->iph.protocol && p->iph.protocol != IPPROTO_GRE) { + bb_error_msg_and_die("%s tunnel mode", "you managed to ask for more than one"); + } + p->iph.protocol = IPPROTO_GRE; + } else if (key == ARG_sit || + key == ARG_ip6_ip) { + if (p->iph.protocol && p->iph.protocol != IPPROTO_IPV6) { + bb_error_msg_and_die("%s tunnel mode", "you managed to ask for more than one"); + } + p->iph.protocol = IPPROTO_IPV6; + } else { + bb_error_msg_and_die("%s tunnel mode", "cannot guess"); + } + } else if (key == ARG_key) { + unsigned uval; + NEXT_ARG(); + p->i_flags |= GRE_KEY; + p->o_flags |= GRE_KEY; + if (strchr(*argv, '.')) + p->i_key = p->o_key = get_addr32(*argv); + else { + if (get_unsigned(&uval, *argv, 0) < 0) { + invarg(*argv, "key"); + } + p->i_key = p->o_key = htonl(uval); + } + } else if (key == ARG_ikey) { + unsigned uval; + NEXT_ARG(); + p->i_flags |= GRE_KEY; + if (strchr(*argv, '.')) + p->o_key = get_addr32(*argv); + else { + if (get_unsigned(&uval, *argv, 0) < 0) { + invarg(*argv, "ikey"); + } + p->i_key = htonl(uval); + } + } else if (key == ARG_okey) { + unsigned uval; + NEXT_ARG(); + p->o_flags |= GRE_KEY; + if (strchr(*argv, '.')) + p->o_key = get_addr32(*argv); + else { + if (get_unsigned(&uval, *argv, 0) < 0) { + invarg(*argv, "okey"); + } + p->o_key = htonl(uval); + } + } else if (key == ARG_seq) { + p->i_flags |= GRE_SEQ; + p->o_flags |= GRE_SEQ; + } else if (key == ARG_iseq) { + p->i_flags |= GRE_SEQ; + } else if (key == ARG_oseq) { + p->o_flags |= GRE_SEQ; + } else if (key == ARG_csum) { + p->i_flags |= GRE_CSUM; + p->o_flags |= GRE_CSUM; + } else if (key == ARG_icsum) { + p->i_flags |= GRE_CSUM; + } else if (key == ARG_ocsum) { + p->o_flags |= GRE_CSUM; + } else if (key == ARG_nopmtudisc) { + p->iph.frag_off = 0; + } else if (key == ARG_pmtudisc) { + p->iph.frag_off = htons(IP_DF); + } else if (key == ARG_remote) { + NEXT_ARG(); + key = index_in_strings(keywords, *argv); + if (key != ARG_any) + p->iph.daddr = get_addr32(*argv); + } else if (key == ARG_local) { + NEXT_ARG(); + key = index_in_strings(keywords, *argv); + if (key != ARG_any) + p->iph.saddr = get_addr32(*argv); + } else if (key == ARG_dev) { + NEXT_ARG(); + strncpy(medium, *argv, IFNAMSIZ-1); + } else if (key == ARG_ttl) { + unsigned uval; + NEXT_ARG(); + key = index_in_strings(keywords, *argv); + if (key != ARG_inherit) { + if (get_unsigned(&uval, *argv, 0)) + invarg(*argv, "TTL"); + if (uval > 255) + invarg(*argv, "TTL must be <=255"); + p->iph.ttl = uval; + } + } else if (key == ARG_tos || + key == ARG_dsfield) { + uint32_t uval; + NEXT_ARG(); + key = index_in_strings(keywords, *argv); + if (key != ARG_inherit) { + if (rtnl_dsfield_a2n(&uval, *argv)) + invarg(*argv, "TOS"); + p->iph.tos = uval; + } else + p->iph.tos = 1; + } else { + if (key == ARG_name) { + NEXT_ARG(); + } + if (p->name[0]) + duparg2("name", *argv); + strncpy(p->name, *argv, IFNAMSIZ); + if (cmd == SIOCCHGTUNNEL && count == 0) { + struct ip_tunnel_parm old_p; + memset(&old_p, 0, sizeof(old_p)); + if (do_get_ioctl(*argv, &old_p)) + exit(EXIT_FAILURE); + *p = old_p; + } + } + count++; + argv++; + } + + if (p->iph.protocol == 0) { + if (memcmp(p->name, "gre", 3) == 0) + p->iph.protocol = IPPROTO_GRE; + else if (memcmp(p->name, "ipip", 4) == 0) + p->iph.protocol = IPPROTO_IPIP; + else if (memcmp(p->name, "sit", 3) == 0) + p->iph.protocol = IPPROTO_IPV6; + } + + if (p->iph.protocol == IPPROTO_IPIP || p->iph.protocol == IPPROTO_IPV6) { + if ((p->i_flags & GRE_KEY) || (p->o_flags & GRE_KEY)) { + bb_error_msg_and_die("keys are not allowed with ipip and sit"); + } + } + + if (medium[0]) { + p->link = do_ioctl_get_ifindex(medium); + } + + if (p->i_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) { + p->i_key = p->iph.daddr; + p->i_flags |= GRE_KEY; + } + if (p->o_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) { + p->o_key = p->iph.daddr; + p->o_flags |= GRE_KEY; + } + if (IN_MULTICAST(ntohl(p->iph.daddr)) && !p->iph.saddr) { + bb_error_msg_and_die("broadcast tunnel requires a source address"); + } +} + + +/* Return value becomes exitcode. It's okay to not return at all */ +static int do_add(int cmd, char **argv) +{ + struct ip_tunnel_parm p; + + parse_args(argv, cmd, &p); + + if (p.iph.ttl && p.iph.frag_off == 0) { + bb_error_msg_and_die("ttl != 0 and noptmudisc are incompatible"); + } + + switch (p.iph.protocol) { + case IPPROTO_IPIP: + return do_add_ioctl(cmd, "tunl0", &p); + case IPPROTO_GRE: + return do_add_ioctl(cmd, "gre0", &p); + case IPPROTO_IPV6: + return do_add_ioctl(cmd, "sit0", &p); + default: + bb_error_msg_and_die("cannot determine tunnel mode (ipip, gre or sit)"); + } +} + +/* Return value becomes exitcode. It's okay to not return at all */ +static int do_del(char **argv) +{ + struct ip_tunnel_parm p; + + parse_args(argv, SIOCDELTUNNEL, &p); + + switch (p.iph.protocol) { + case IPPROTO_IPIP: + return do_del_ioctl("tunl0", &p); + case IPPROTO_GRE: + return do_del_ioctl("gre0", &p); + case IPPROTO_IPV6: + return do_del_ioctl("sit0", &p); + default: + return do_del_ioctl(p.name, &p); + } +} + +static void print_tunnel(struct ip_tunnel_parm *p) +{ + char s1[256]; + char s2[256]; + char s3[64]; + char s4[64]; + + format_host(AF_INET, 4, &p->iph.daddr, s1, sizeof(s1)); + format_host(AF_INET, 4, &p->iph.saddr, s2, sizeof(s2)); + inet_ntop(AF_INET, &p->i_key, s3, sizeof(s3)); + inet_ntop(AF_INET, &p->o_key, s4, sizeof(s4)); + + printf("%s: %s/ip remote %s local %s ", + p->name, + p->iph.protocol == IPPROTO_IPIP ? "ip" : + (p->iph.protocol == IPPROTO_GRE ? "gre" : + (p->iph.protocol == IPPROTO_IPV6 ? "ipv6" : "unknown")), + p->iph.daddr ? s1 : "any", p->iph.saddr ? s2 : "any"); + if (p->link) { + char *n = do_ioctl_get_ifname(p->link); + if (n) { + printf(" dev %s ", n); + free(n); + } + } + if (p->iph.ttl) + printf(" ttl %d ", p->iph.ttl); + else + printf(" ttl inherit "); + if (p->iph.tos) { + SPRINT_BUF(b1); + printf(" tos"); + if (p->iph.tos & 1) + printf(" inherit"); + if (p->iph.tos & ~1) + printf("%c%s ", p->iph.tos & 1 ? '/' : ' ', + rtnl_dsfield_n2a(p->iph.tos & ~1, b1, sizeof(b1))); + } + if (!(p->iph.frag_off & htons(IP_DF))) + printf(" nopmtudisc"); + + if ((p->i_flags & GRE_KEY) && (p->o_flags & GRE_KEY) && p->o_key == p->i_key) + printf(" key %s", s3); + else if ((p->i_flags | p->o_flags) & GRE_KEY) { + if (p->i_flags & GRE_KEY) + printf(" ikey %s ", s3); + if (p->o_flags & GRE_KEY) + printf(" okey %s ", s4); + } + + if (p->i_flags & GRE_SEQ) + printf("%c Drop packets out of sequence.\n", _SL_); + if (p->i_flags & GRE_CSUM) + printf("%c Checksum in received packet is required.", _SL_); + if (p->o_flags & GRE_SEQ) + printf("%c Sequence packets on output.", _SL_); + if (p->o_flags & GRE_CSUM) + printf("%c Checksum output packets.", _SL_); +} + +static void do_tunnels_list(struct ip_tunnel_parm *p) +{ + char name[IFNAMSIZ]; + unsigned long rx_bytes, rx_packets, rx_errs, rx_drops, + rx_fifo, rx_frame, + tx_bytes, tx_packets, tx_errs, tx_drops, + tx_fifo, tx_colls, tx_carrier, rx_multi; + int type; + struct ip_tunnel_parm p1; + char buf[512]; + FILE *fp = fopen_or_warn("/proc/net/dev", "r"); + + if (fp == NULL) { + return; + } + /* skip headers */ + fgets(buf, sizeof(buf), fp); + fgets(buf, sizeof(buf), fp); + + while (fgets(buf, sizeof(buf), fp) != NULL) { + char *ptr; + + /*buf[sizeof(buf) - 1] = 0; - fgets is safe anyway */ + ptr = strchr(buf, ':'); + if (ptr == NULL || + (*ptr++ = 0, sscanf(buf, "%s", name) != 1)) { + bb_error_msg("wrong format of /proc/net/dev"); + return; + } + if (sscanf(ptr, "%lu%lu%lu%lu%lu%lu%lu%*d%lu%lu%lu%lu%lu%lu%lu", + &rx_bytes, &rx_packets, &rx_errs, &rx_drops, + &rx_fifo, &rx_frame, &rx_multi, + &tx_bytes, &tx_packets, &tx_errs, &tx_drops, + &tx_fifo, &tx_colls, &tx_carrier) != 14) + continue; + if (p->name[0] && strcmp(p->name, name)) + continue; + type = do_ioctl_get_iftype(name); + if (type == -1) { + bb_error_msg("cannot get type of [%s]", name); + continue; + } + if (type != ARPHRD_TUNNEL && type != ARPHRD_IPGRE && type != ARPHRD_SIT) + continue; + memset(&p1, 0, sizeof(p1)); + if (do_get_ioctl(name, &p1)) + continue; + if ((p->link && p1.link != p->link) || + (p->name[0] && strcmp(p1.name, p->name)) || + (p->iph.daddr && p1.iph.daddr != p->iph.daddr) || + (p->iph.saddr && p1.iph.saddr != p->iph.saddr) || + (p->i_key && p1.i_key != p->i_key)) + continue; + print_tunnel(&p1); + bb_putchar('\n'); + } +} + +/* Return value becomes exitcode. It's okay to not return at all */ +static int do_show(char **argv) +{ + int err; + struct ip_tunnel_parm p; + + parse_args(argv, SIOCGETTUNNEL, &p); + + switch (p.iph.protocol) { + case IPPROTO_IPIP: + err = do_get_ioctl(p.name[0] ? p.name : "tunl0", &p); + break; + case IPPROTO_GRE: + err = do_get_ioctl(p.name[0] ? p.name : "gre0", &p); + break; + case IPPROTO_IPV6: + err = do_get_ioctl(p.name[0] ? p.name : "sit0", &p); + break; + default: + do_tunnels_list(&p); + return 0; + } + if (err) + return -1; + + print_tunnel(&p); + bb_putchar('\n'); + return 0; +} + +/* Return value becomes exitcode. It's okay to not return at all */ +int do_iptunnel(char **argv) +{ + static const char keywords[] ALIGN1 = + "add\0""change\0""delete\0""show\0""list\0""lst\0"; + enum { ARG_add = 0, ARG_change, ARG_del, ARG_show, ARG_list, ARG_lst }; + int key; + + if (*argv) { + key = index_in_substrings(keywords, *argv); + if (key < 0) + bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name); + argv++; + if (key == ARG_add) + return do_add(SIOCADDTUNNEL, argv); + if (key == ARG_change) + return do_add(SIOCCHGTUNNEL, argv); + if (key == ARG_del) + return do_del(argv); + } + return do_show(argv); +} |