Pablo Neira Ayuso | 4b075b6 | 2015-11-17 12:22:42 +0100 | [diff] [blame^] | 1 | #ifdef __linux__ |
| 2 | #define _GNU_SOURCE 1 /* strdup() prototype, broken arpa/inet.h */ |
| 3 | #endif |
| 4 | |
| 5 | #include "../config.h" |
| 6 | |
| 7 | #ifdef HAVE_STDINT_H |
| 8 | #include <stdint.h> |
| 9 | #endif |
| 10 | |
| 11 | #include <syslog.h> |
| 12 | #include <stdio.h> |
| 13 | #include <string.h> |
| 14 | #include <stdlib.h> |
| 15 | #include <sys/types.h> |
| 16 | #include <arpa/inet.h> |
| 17 | #include <net/if.h> |
| 18 | |
| 19 | #include <libgtpnl/gtp.h> |
| 20 | #include <libgtpnl/gtpnl.h> |
| 21 | #include <libmnl/libmnl.h> |
| 22 | |
| 23 | #include <errno.h> |
| 24 | |
| 25 | #include <time.h> |
| 26 | |
| 27 | #include "../lib/tun.h" |
| 28 | #include "../lib/syserr.h" |
| 29 | #include "../gtp/pdp.h" |
| 30 | #include "../gtp/gtp.h" |
| 31 | #include "cmdline.h" |
| 32 | |
| 33 | #include <libgtpnl/gtp.h> |
| 34 | #include <libgtpnl/gtpnl.h> |
| 35 | #include <libmnl/libmnl.h> |
| 36 | |
| 37 | #include "gtp-kernel.h" |
| 38 | |
| 39 | static void pdp_debug(struct pdp_t *pdp) |
| 40 | { |
| 41 | int i; |
| 42 | uint64_t teid; |
| 43 | |
| 44 | if (!debug) |
| 45 | return; |
| 46 | |
| 47 | printf("version %u\n", pdp->version); |
| 48 | if (pdp->version == 0) { |
| 49 | teid = pdp_gettid(pdp->imsi, pdp->nsapi); |
| 50 | printf("flowid %u\n", pdp->flru); |
| 51 | } else { |
| 52 | teid = pdp->teid_gn; /* GTPIE_TEI_DI */ |
| 53 | } |
| 54 | |
| 55 | printf("teid %llx\n", teid); |
| 56 | printf("address (%u)\n", pdp->eua.l); |
| 57 | |
| 58 | /* Byte 0: 0xf1 == IETF */ |
| 59 | /* Byte 1: 0x21 == IPv4 */ |
| 60 | /* Byte 2-6: IPv4 address */ |
| 61 | |
| 62 | for (i = 0; i < 6; i++) |
| 63 | printf("%x ", pdp->eua.v[i] & 0xff); /* GTPIE_EUA */ |
| 64 | |
| 65 | printf("\n"); |
| 66 | printf("sgsn-addr (%u)\n", pdp->gsnrc.l); |
| 67 | |
| 68 | for (i = 0; i < 4; i++) |
| 69 | printf("%x ", pdp->gsnrc.v[i] & 0xff); /* GTPIE_GSN_ADDR */ |
| 70 | |
| 71 | printf("\n"); |
| 72 | } |
| 73 | |
| 74 | static int mask2prefix(struct in_addr *mask) |
| 75 | { |
| 76 | uint32_t tmp = ntohl(mask->s_addr); |
| 77 | int k; |
| 78 | |
| 79 | for (k=0; tmp > 0; k++) |
| 80 | tmp = (tmp << 1); |
| 81 | |
| 82 | return k; |
| 83 | } |
| 84 | |
| 85 | static struct { |
| 86 | int genl_id; |
| 87 | struct mnl_socket *nl; |
| 88 | bool enabled; |
| 89 | } gtp_nl; |
| 90 | |
| 91 | /* Always forces the kernel to allocate gtp0. If it exists it hits EEXIST */ |
| 92 | #define GTP_DEVNAME "gtp0" |
| 93 | |
| 94 | int gtp_kernel_init(struct gsn_t *gsn, struct in_addr *net, |
| 95 | struct in_addr *mask, |
| 96 | struct gengetopt_args_info *args_info) |
| 97 | { |
| 98 | if (!args_info->gtpnl_given) |
| 99 | return 0; |
| 100 | |
| 101 | if (gtp_dev_create(GTP_DEVNAME, args_info->gtpnl_orig, |
| 102 | gsn->fd0, gsn->fd1u) < 0) { |
| 103 | sys_err(LOG_ERR, __FILE__, __LINE__, 0, |
| 104 | "cannot create GTP tunnel device: %s\n", |
| 105 | strerror(errno)); |
| 106 | return -1; |
| 107 | } |
| 108 | gtp_nl.enabled = true; |
| 109 | |
| 110 | gtp_nl.nl = genl_socket_open(); |
| 111 | if (gtp_nl.nl == NULL) { |
| 112 | sys_err(LOG_ERR, __FILE__, __LINE__, 0, |
| 113 | "cannot create genetlink socket\n"); |
| 114 | return -1; |
| 115 | } |
| 116 | gtp_nl.genl_id = genl_lookup_family(gtp_nl.nl, "gtp"); |
| 117 | if (gtp_nl.genl_id < 0) { |
| 118 | sys_err(LOG_ERR, __FILE__, __LINE__, 0, |
| 119 | "cannot lookup GTP genetlink ID\n"); |
| 120 | return -1; |
| 121 | } |
| 122 | if (debug) { |
| 123 | sys_err(LOG_NOTICE, __FILE__, __LINE__, 0, |
| 124 | "Using the GTP kernel mode (genl ID is %d)\n", |
| 125 | gtp_nl.genl_id); |
| 126 | } |
| 127 | |
| 128 | if (debug) { |
| 129 | printf("Setting route to reach %s via %s\n", |
| 130 | args_info->net_arg, GTP_DEVNAME); |
| 131 | } |
| 132 | |
| 133 | if (gtp_dev_config(GTP_DEVNAME, net, mask2prefix(mask)) < 0) { |
| 134 | sys_err(LOG_ERR, __FILE__, __LINE__, 0, |
| 135 | "Cannot add route to reach network %s\n", |
| 136 | args_info->net_arg); |
| 137 | } |
| 138 | |
| 139 | /* launch script if it is set to bring up the route to reach |
| 140 | * the MS, eg. ip ro add 10.0.0.0/8 dev gtp0. Better add this |
| 141 | * using native rtnetlink interface given that we know the |
| 142 | * MS network mask, later. |
| 143 | */ |
| 144 | if (ipup) { |
| 145 | char cmd[1024]; |
| 146 | int err; |
| 147 | |
| 148 | /* eg. /home/ggsn/ipup gtp0 10.0.0.0/8 */ |
| 149 | snprintf(cmd, sizeof(cmd), "%s %s %s", |
| 150 | ipup, GTP_DEVNAME, args_info->net_arg); |
| 151 | cmd[sizeof(cmd)-1] = '\0'; |
| 152 | |
| 153 | err = system(cmd); |
| 154 | if (err < 0) { |
| 155 | sys_err(LOG_ERR, __FILE__, __LINE__, 0, |
| 156 | "Failed to launch script `%s'", ipup); |
| 157 | return -1; |
| 158 | } |
| 159 | } |
| 160 | sys_err(LOG_NOTICE, __FILE__, __LINE__, 0, "GTP kernel configured\n"); |
| 161 | |
| 162 | return 0; |
| 163 | } |
| 164 | |
| 165 | void gtp_kernel_stop(void) |
| 166 | { |
| 167 | if (!gtp_nl.enabled) |
| 168 | return; |
| 169 | |
| 170 | gtp_dev_destroy(GTP_DEVNAME); |
| 171 | } |
| 172 | |
| 173 | int gtp_kernel_tunnel_add(struct pdp_t *pdp) |
| 174 | { |
| 175 | struct in_addr ms, sgsn; |
| 176 | struct gtp_tunnel *t; |
| 177 | int ret; |
| 178 | |
| 179 | if (!gtp_nl.enabled) |
| 180 | return 0; |
| 181 | |
| 182 | pdp_debug(pdp); |
| 183 | |
| 184 | t = gtp_tunnel_alloc(); |
| 185 | if (t == NULL) |
| 186 | return -1; |
| 187 | |
| 188 | memcpy(&ms, &pdp->eua.v[2], sizeof(struct in_addr)); |
| 189 | memcpy(&sgsn, &pdp->gsnrc.v[0], sizeof(struct in_addr)); |
| 190 | |
| 191 | gtp_tunnel_set_ifidx(t, if_nametoindex(GTP_DEVNAME)); |
| 192 | gtp_tunnel_set_version(t, pdp->version); |
| 193 | gtp_tunnel_set_ms_ip4(t, &ms); |
| 194 | gtp_tunnel_set_sgsn_ip4(t, &sgsn); |
| 195 | if (pdp->version == 0) { |
| 196 | gtp_tunnel_set_tid(t, pdp_gettid(pdp->imsi, pdp->nsapi)); |
| 197 | gtp_tunnel_set_flowid(t, pdp->flru); |
| 198 | } else { |
| 199 | gtp_tunnel_set_tid(t, pdp->teid_gn); /* GTPIE_TEI_DI */ |
| 200 | } |
| 201 | |
| 202 | ret = gtp_add_tunnel(gtp_nl.genl_id, gtp_nl.nl, t); |
| 203 | gtp_tunnel_free(t); |
| 204 | |
| 205 | return ret; |
| 206 | } |
| 207 | |
| 208 | int gtp_kernel_tunnel_del(struct pdp_t *pdp) |
| 209 | { |
| 210 | struct gtp_tunnel *t; |
| 211 | int ret; |
| 212 | |
| 213 | if (!gtp_nl.enabled) |
| 214 | return 0; |
| 215 | |
| 216 | pdp_debug(pdp); |
| 217 | |
| 218 | t = gtp_tunnel_alloc(); |
| 219 | if (t == NULL) |
| 220 | return -1; |
| 221 | |
| 222 | gtp_tunnel_set_ifidx(t, if_nametoindex(GTP_DEVNAME)); |
| 223 | gtp_tunnel_set_version(t, pdp->version); |
| 224 | if (pdp->version == 0) { |
| 225 | gtp_tunnel_set_tid(t, pdp_gettid(pdp->imsi, pdp->nsapi)); |
| 226 | gtp_tunnel_set_flowid(t, pdp->flru); |
| 227 | } else { |
| 228 | gtp_tunnel_set_tid(t, pdp->teid_gn); /* GTPIE_TEI_DI */ |
| 229 | } |
| 230 | |
| 231 | ret = gtp_del_tunnel(gtp_nl.genl_id, gtp_nl.nl, t); |
| 232 | gtp_tunnel_free(t); |
| 233 | |
| 234 | return ret; |
| 235 | } |
| 236 | |
| 237 | int gtp_kernel_enabled(void) |
| 238 | { |
| 239 | return gtp_nl.enabled; |
| 240 | } |