| /* (C) 2008-2012 by Harald Welte <laforge@gnumonks.org> |
| * |
| * All Rights Reserved |
| * |
| * Author: Harald Welte <laforge@gnumonks.org> |
| * Pablo Neira Ayuso <pablo@gnumonks.org> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU Affero General Public License as published by |
| * the Free Software Foundation; either version 3 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU Affero General Public License for more details. |
| * |
| * You should have received a copy of the GNU Affero General Public License |
| * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| * |
| */ |
| |
| #include <stdio.h> |
| #include <stdint.h> |
| #include <stddef.h> |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <fcntl.h> |
| #include <unistd.h> |
| #include <sys/time.h> |
| #include <arpa/inet.h> |
| #include <string.h> |
| #include <errno.h> |
| |
| #include <osmocom/core/msgb.h> |
| #include <osmocom/core/logging.h> |
| #include <osmocom/core/utils.h> |
| |
| #include <osmocom/abis/lapd_pcap.h> |
| |
| /* |
| * pcap writing of the mlapd load |
| * pcap format is from http://wiki.wireshark.org/Development/LibpcapFileFormat |
| */ |
| #define DLT_LINUX_LAPD 177 |
| #define LINUX_SLL_HOST 0 |
| #define LINUX_SLL_OUTGOING 4 |
| |
| struct pcap_hdr { |
| uint32_t magic_number; |
| uint16_t version_major; |
| uint16_t version_minor; |
| int32_t thiszone; |
| uint32_t sigfigs; |
| uint32_t snaplen; |
| uint32_t network; |
| } __attribute__((packed)); |
| |
| struct pcap_rechdr { |
| uint32_t ts_sec; |
| uint32_t ts_usec; |
| uint32_t incl_len; |
| uint32_t orig_len; |
| } __attribute__((packed)); |
| |
| struct pcap_lapdhdr { |
| uint16_t pkttype; |
| uint16_t hatype; |
| uint16_t halen; |
| uint8_t addr[8]; |
| int16_t protocol; |
| } __attribute__((packed)); |
| |
| osmo_static_assert(offsetof(struct pcap_lapdhdr, hatype) == 2, hatype_offset); |
| osmo_static_assert(offsetof(struct pcap_lapdhdr, halen) == 4, halen_offset); |
| osmo_static_assert(offsetof(struct pcap_lapdhdr, addr) == 6, addr_offset); |
| osmo_static_assert(offsetof(struct pcap_lapdhdr, protocol) == 14, proto_offset); |
| osmo_static_assert(sizeof(struct pcap_lapdhdr) == 16, lapd_header_size); |
| |
| int osmo_pcap_lapd_set_fd(int fd) |
| { |
| struct pcap_hdr pcap_header = { |
| .magic_number = 0xa1b2c3d4, |
| .version_major = 2, |
| .version_minor = 4, |
| .thiszone = 0, |
| .sigfigs = 0, |
| .snaplen = 65535, |
| .network = DLT_LINUX_LAPD, |
| }; |
| |
| if (write(fd, &pcap_header, sizeof(pcap_header)) |
| != sizeof(pcap_header)) { |
| LOGP(DLLAPD, LOGL_ERROR, "cannot write PCAP header: %s\n", |
| strerror(errno)); |
| close(fd); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| int osmo_pcap_lapd_open(char *filename, mode_t mode) |
| { |
| int fd, rc; |
| |
| LOGP(DLLAPD, LOGL_NOTICE, "opening LAPD pcap file `%s'\n", filename); |
| |
| fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, mode); |
| if (fd < 0) { |
| LOGP(DLLAPD, LOGL_ERROR, "failed to open PCAP file: %s\n", |
| strerror(errno)); |
| return -1; |
| } |
| |
| rc = osmo_pcap_lapd_set_fd(fd); |
| if (rc < 0) { |
| close(fd); |
| return rc; |
| } |
| |
| return fd; |
| } |
| |
| /* This currently only works for the D-Channel */ |
| int osmo_pcap_lapd_write(int fd, int direction, struct msgb *msg) |
| { |
| int numbytes = 0; |
| struct timeval tv; |
| struct pcap_rechdr pcap_rechdr; |
| struct pcap_lapdhdr header; |
| char buf[sizeof(struct pcap_rechdr) + |
| sizeof(struct pcap_lapdhdr) + msg->len]; |
| |
| /* PCAP file has not been opened, skip. */ |
| if (fd < 0) |
| return 0; |
| |
| pcap_rechdr.ts_sec = 0; |
| pcap_rechdr.ts_usec = 0; |
| pcap_rechdr.incl_len = msg->len + sizeof(struct pcap_lapdhdr); |
| pcap_rechdr.orig_len = msg->len + sizeof(struct pcap_lapdhdr); |
| |
| if (direction == OSMO_LAPD_PCAP_OUTPUT) |
| header.pkttype = htons(LINUX_SLL_OUTGOING); |
| else |
| header.pkttype = htons(LINUX_SLL_HOST); |
| header.hatype = 0; |
| header.halen = 0; |
| header.addr[0] = 0x01; /* we are the network side */ |
| header.protocol = ntohs(48); |
| |
| gettimeofday(&tv, NULL); |
| pcap_rechdr.ts_sec = tv.tv_sec; |
| pcap_rechdr.ts_usec = tv.tv_usec; |
| |
| memcpy(buf + numbytes, &pcap_rechdr, sizeof(pcap_rechdr)); |
| numbytes += sizeof(pcap_rechdr); |
| |
| memcpy(buf + numbytes, &header, sizeof(header)); |
| numbytes += sizeof(header); |
| |
| memcpy(buf + numbytes, msg->data, msg->len); |
| numbytes += msg->len; |
| |
| if (write(fd, buf, numbytes) != numbytes) { |
| LOGP(DLLAPD, LOGL_ERROR, "cannot write packet to PCAP: %s\n", |
| strerror(errno)); |
| return -1; |
| } |
| return numbytes; |
| } |
| |
| int osmo_pcap_lapd_close(int fd) |
| { |
| LOGP(DLLAPD, LOGL_NOTICE, "closing LAPD pcap file\n"); |
| return close(fd); |
| } |