diff options
Diffstat (limited to 'pcap/ulogd_PCAP.c')
| -rw-r--r-- | pcap/ulogd_PCAP.c | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/pcap/ulogd_PCAP.c b/pcap/ulogd_PCAP.c new file mode 100644 index 0000000..686fe47 --- /dev/null +++ b/pcap/ulogd_PCAP.c @@ -0,0 +1,286 @@ +/* ulogd_PCAP.c, Version $Revision$ + * + * ulogd output target for writing pcap-style files (like tcpdump) + * + * FIXME: descr. + * + * + * (C) 2002 by Harald Welte <laforge@gnumonks.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation + * + * 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * $Id$ + * + */ + +#include <stdio.h> +#include <stdlib.h> +#include <stdint.h> +#include <unistd.h> +#include <string.h> +#include <time.h> +#include <sys/time.h> +#include <sys/stat.h> +#include <pcap.h> +#include <ulogd/ulogd.h> +#include <ulogd/conffile.h> + +/* + * This is a timeval as stored in disk in a dumpfile. + * It has to use the same types everywhere, independent of the actual + * `struct timeval' + */ + +struct pcap_timeval { + int32_t tv_sec; /* seconds */ + int32_t tv_usec; /* microseconds */ +}; + +/* + * How a `pcap_pkthdr' is actually stored in the dumpfile. + * + * Do not change the format of this structure, in any way (this includes + * changes that only affect the length of fields in this structure), + * and do not make the time stamp anything other than seconds and + * microseconds (e.g., seconds and nanoseconds). Instead: + * + * introduce a new structure for the new format; + * + * send mail to "tcpdump-workers@tcpdump.org", requesting a new + * magic number for your new capture file format, and, when + * you get the new magic number, put it in "savefile.c"; + * + * use that magic number for save files with the changed record + * header; + * + * make the code in "savefile.c" capable of reading files with + * the old record header as well as files with the new record header + * (using the magic number to determine the header format). + * + * Then supply the changes to "patches@tcpdump.org", so that future + * versions of libpcap and programs that use it (such as tcpdump) will + * be able to read your new capture file format. + */ + +struct pcap_sf_pkthdr { + struct pcap_timeval ts; /* time stamp */ + uint32_t caplen; /* length of portion present */ + uint32_t len; /* length this packet (off wire) */ +}; + +#ifndef ULOGD_PCAP_DEFAULT +#define ULOGD_PCAP_DEFAULT "/var/log/ulogd.pcap" +#endif + +#ifndef ULOGD_PCAP_SYNC_DEFAULT +#define ULOGD_PCAP_SYNC_DEFAULT 0 +#endif + +#define NIPQUAD(addr) \ + ((unsigned char *)&addr)[0], \ + ((unsigned char *)&addr)[1], \ + ((unsigned char *)&addr)[2], \ + ((unsigned char *)&addr)[3] + +static config_entry_t pcapf_ce = { + .key = "file", + .type = CONFIG_TYPE_STRING, + .options = CONFIG_OPT_NONE, + .u = { .string = ULOGD_PCAP_DEFAULT } +}; + +static config_entry_t pcapsync_ce = { + .next = &pcapf_ce, + .key = "sync", + .type = CONFIG_TYPE_INT, + .options = CONFIG_OPT_NONE, + .u = { .value = ULOGD_PCAP_SYNC_DEFAULT } +}; + +static FILE *of = NULL; + +struct intr_id { + char* name; + unsigned int id; +}; + +#define INTR_IDS 5 +static struct intr_id intr_ids[INTR_IDS] = { + { "raw.pkt", 0 }, + { "raw.pktlen", 0 }, + { "ip.totlen", 0 }, + { "oob.time.sec", 0 }, + { "oob.time.usec", 0 }, +}; + +#define GET_VALUE(x) ulogd_keyh[intr_ids[x].id].interp->result[ulogd_keyh[intr_ids[x].id].offset].value +#define GET_FLAGS(x) ulogd_keyh[intr_ids[x].id].interp->result[ulogd_keyh[intr_ids[x].id].offset].flags + +static int pcap_output(ulog_iret_t *res) +{ + struct pcap_sf_pkthdr pchdr; + + pchdr.caplen = GET_VALUE(1).ui32; + pchdr.len = GET_VALUE(2).ui32; + + if (GET_FLAGS(3) & ULOGD_RETF_VALID + && GET_FLAGS(4) & ULOGD_RETF_VALID) { + pchdr.ts.tv_sec = GET_VALUE(3).ui32; + pchdr.ts.tv_usec = GET_VALUE(4).ui32; + } else { + /* use current system time */ + struct timeval tv; + gettimeofday(&tv, NULL); + + pchdr.ts.tv_sec = tv.tv_sec; + pchdr.ts.tv_usec = tv.tv_usec; + } + + if (fwrite(&pchdr, sizeof(pchdr), 1, of) != 1) { + ulogd_log(ULOGD_ERROR, "Error during write: %s\n", + strerror(errno)); + return 1; + } + if (fwrite(GET_VALUE(0).ptr, pchdr.caplen, 1, of) != 1) { + ulogd_log(ULOGD_ERROR, "Error during write: %s\n", + strerror(errno)); + return 1; + } + + if (pcapsync_ce.u.value) + fflush(of); + + return 0; +} + +/* stolen from libpcap savefile.c */ +#define LINKTYPE_RAW 101 +#define TCPDUMP_MAGIC 0xa1b2c3d4 + +static int write_pcap_header(void) +{ + struct pcap_file_header pcfh; + int ret; + + pcfh.magic = TCPDUMP_MAGIC; + pcfh.version_major = PCAP_VERSION_MAJOR; + pcfh.version_minor = PCAP_VERSION_MINOR; + pcfh.thiszone = timezone; + pcfh.sigfigs = 0; + pcfh.snaplen = 65535; /* we don't know the length in advance */ + pcfh.linktype = LINKTYPE_RAW; + + ret = fwrite(&pcfh, sizeof(pcfh), 1, of); + fflush(of); + + return ret; +} + +/* get all key id's for the keys we are intrested in */ +static int get_ids(void) +{ + int i; + struct intr_id *cur_id; + + for (i = 0; i < INTR_IDS; i++) { + cur_id = &intr_ids[i]; + cur_id->id = keyh_getid(cur_id->name); + if (!cur_id->id) { + ulogd_log(ULOGD_ERROR, + "Cannot resolve keyhash id for %s\n", + cur_id->name); + return 1; + } + } + return 0; +} + +void append_create_outfile(void) { + struct stat st_dummy; + int exist = 0; + + if (stat(pcapf_ce.u.string, &st_dummy) == 0 && st_dummy.st_size > 0) { + exist = 1; + } + + if (!exist) { + of = fopen(pcapf_ce.u.string, "w"); + if (!of) { + ulogd_log(ULOGD_FATAL, "can't open pcap file %s: %s\n", + pcapf_ce.u.string, strerror(errno)); + exit(2); + } + if (!write_pcap_header()) { + ulogd_log(ULOGD_FATAL, "can't write pcap header: %s\n", + strerror(errno)); + exit(2); + } + } else { + of = fopen(pcapf_ce.u.string, "a"); + if (!of) { + ulogd_log(ULOGD_FATAL, "can't open pcap file: %s\n", + strerror(errno)); + exit(2); + } + } +} + +static void pcap_signal_handler(int signal) +{ + switch (signal) { + case SIGHUP: + ulogd_log(ULOGD_NOTICE, "pcap: reopening capture file\n"); + fclose(of); + append_create_outfile(); + break; + default: + break; + } +} + +static int pcap_init(void) +{ + /* FIXME: error handling */ + config_parse_file("PCAP", &pcapsync_ce); + +#ifdef DEBUG_PCAP + of = stdout; +#else + append_create_outfile(); +#endif + return 0; +} + +static void pcap_fini(void) +{ + if (of) + fclose(of); +} + +static ulog_output_t pcap_op = { + .name = "pcap", + .init = &pcap_init, + .fini = &pcap_fini, + .output = &pcap_output, + .signal = &pcap_signal_handler, +}; + +void _init(void) +{ + if (get_ids()) { + ulogd_log(ULOGD_ERROR, "can't resolve all keyhash id's\n"); + } + + register_output(&pcap_op); +} |