/* netscreen.c * * Juniper NetScreen snoop output parser * Created by re-using a lot of code from cosine.c * Copyright (c) 2007 by Sake Blok * * Wiretap Library * Copyright (c) 1998 by Gilbert Ramirez * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * 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 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "config.h" #include "wtap-int.h" #include "netscreen.h" #include "file_wrappers.h" #include #include /* XXX TODO: * * o Construct a list of interfaces, with interface names, give * them link-layer types based on the interface name and packet * data, and supply interface IDs with each packet (i.e., make * this supply a pcap-ng-style set of interfaces and associate * packets with interfaces). This is probably the right way * to "Pass the interface names and the traffic direction to either * the frame-structure, a pseudo-header or use PPI." See the * message at * * http://www.wireshark.org/lists/wireshark-dev/200708/msg00029.html * * to see whether any further discussion is still needed. I suspect * it doesn't; pcap-NG existed at the time, as per the final * message in that thread: * * http://www.wireshark.org/lists/wireshark-dev/200708/msg00039.html * * but I don't think we fully *supported* it at that point. Now * that we do, we have the infrastructure to support this, except * that we currently have no way to translate interface IDs to * interface names in the "frame" dissector or to supply interface * information as part of the packet metadata from Wiretap modules. * That should be fixed so that we can show interface information, * such as the interface name, in packet dissections from, for example, * pcap-NG captures. */ static gboolean info_line(const gchar *line); static gint64 netscreen_seek_next_packet(wtap *wth, int *err, gchar **err_info, char *hdr); static gboolean netscreen_check_file_type(wtap *wth, int *err, gchar **err_info); static gboolean netscreen_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset); static gboolean netscreen_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info); static int parse_netscreen_rec_hdr(struct wtap_pkthdr *phdr, const char *line, char *cap_int, gboolean *cap_dir, char *cap_dst, int *err, gchar **err_info); static gboolean parse_netscreen_hex_dump(FILE_T fh, int pkt_len, const char *cap_int, const char *cap_dst, struct wtap_pkthdr *phdr, Buffer* buf, int *err, gchar **err_info); static int parse_single_hex_dump_line(char* rec, guint8 *buf, guint byte_offset); /* Returns TRUE if the line appears to be a line with protocol info. Otherwise it returns FALSE. */ static gboolean info_line(const gchar *line) { int i=NETSCREEN_SPACES_ON_INFO_LINE; while (i-- > 0) { if (g_ascii_isspace(*line)) { line++; continue; } else { return FALSE; } } return TRUE; } /* Seeks to the beginning of the next packet, and returns the byte offset. Copy the header line to hdr. Returns -1 on failure, and sets "*err" to the error and sets "*err_info" to null or an additional error string. */ static gint64 netscreen_seek_next_packet(wtap *wth, int *err, gchar **err_info, char *hdr) { gint64 cur_off; char buf[NETSCREEN_LINE_LENGTH]; while (1) { cur_off = file_tell(wth->fh); if (cur_off == -1) { /* Error */ *err = file_error(wth->fh, err_info); return -1; } if (file_gets(buf, sizeof(buf), wth->fh) == NULL) { /* EOF or error. */ *err = file_error(wth->fh, err_info); break; } if (strstr(buf, NETSCREEN_REC_MAGIC_STR1) || strstr(buf, NETSCREEN_REC_MAGIC_STR2)) { g_strlcpy(hdr, buf, NETSCREEN_LINE_LENGTH); return cur_off; } } return -1; } /* Look through the first part of a file to see if this is * NetScreen snoop output. * * Returns TRUE if it is, FALSE if it isn't or if we get an I/O error; * if we get an I/O error, "*err" will be set to a non-zero value and * "*err_info" is set to null or an additional error string. */ static gboolean netscreen_check_file_type(wtap *wth, int *err, gchar **err_info) { char buf[NETSCREEN_LINE_LENGTH]; guint reclen, line; buf[NETSCREEN_LINE_LENGTH-1] = '\0'; for (line = 0; line < NETSCREEN_HEADER_LINES_TO_CHECK; line++) { if (file_gets(buf, NETSCREEN_LINE_LENGTH, wth->fh) == NULL) { /* EOF or error. */ *err = file_error(wth->fh, err_info); return FALSE; } reclen = (guint) strlen(buf); if (reclen < strlen(NETSCREEN_HDR_MAGIC_STR1) || reclen < strlen(NETSCREEN_HDR_MAGIC_STR2)) { continue; } if (strstr(buf, NETSCREEN_HDR_MAGIC_STR1) || strstr(buf, NETSCREEN_HDR_MAGIC_STR2)) { return TRUE; } } *err = 0; return FALSE; } wtap_open_return_val netscreen_open(wtap *wth, int *err, gchar **err_info) { /* Look for a NetScreen snoop header line */ if (!netscreen_check_file_type(wth, err, err_info)) { if (*err != 0 && *err != WTAP_ERR_SHORT_READ) return WTAP_OPEN_ERROR; return WTAP_OPEN_NOT_MINE; } if (file_seek(wth->fh, 0L, SEEK_SET, err) == -1) /* rewind */ return WTAP_OPEN_ERROR; wth->file_encap = WTAP_ENCAP_UNKNOWN; wth->file_type_subtype = WTAP_FILE_TYPE_SUBTYPE_NETSCREEN; wth->snapshot_length = 0; /* not known */ wth->subtype_read = netscreen_read; wth->subtype_seek_read = netscreen_seek_read; wth->file_tsprec = WTAP_TSPREC_DSEC; return WTAP_OPEN_MINE; } /* Find the next packet and parse it; called from wtap_read(). */ static gboolean netscreen_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset) { gint64 offset; int pkt_len; char line[NETSCREEN_LINE_LENGTH]; char cap_int[NETSCREEN_MAX_INT_NAME_LENGTH]; gboolean cap_dir; char cap_dst[13]; /* Find the next packet */ offset = netscreen_seek_next_packet(wth, err, err_info, line); if (offset < 0) return FALSE; /* Parse the header */ pkt_len = parse_netscreen_rec_hdr(&wth->phdr, line, cap_int, &cap_dir, cap_dst, err, err_info); if (pkt_len == -1) return FALSE; /* Convert the ASCII hex dump to binary data, and fill in some struct wtap_pkthdr fields */ if (!parse_netscreen_hex_dump(wth->fh, pkt_len, cap_int, cap_dst, &wth->phdr, wth->frame_buffer, err, err_info)) return FALSE; /* * If the per-file encapsulation isn't known, set it to this * packet's encapsulation. * * If it *is* known, and it isn't this packet's encapsulation, * set it to WTAP_ENCAP_PER_PACKET, as this file doesn't * have a single encapsulation for all packets in the file. */ if (wth->file_encap == WTAP_ENCAP_UNKNOWN) wth->file_encap = wth->phdr.pkt_encap; else { if (wth->file_encap != wth->phdr.pkt_encap) wth->file_encap = WTAP_ENCAP_PER_PACKET; } *data_offset = offset; return TRUE; } /* Used to read packets in random-access fashion */ static gboolean netscreen_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info) { int pkt_len; char line[NETSCREEN_LINE_LENGTH]; char cap_int[NETSCREEN_MAX_INT_NAME_LENGTH]; gboolean cap_dir; char cap_dst[13]; if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1) { return FALSE; } if (file_gets(line, NETSCREEN_LINE_LENGTH, wth->random_fh) == NULL) { *err = file_error(wth->random_fh, err_info); if (*err == 0) { *err = WTAP_ERR_SHORT_READ; } return FALSE; } pkt_len = parse_netscreen_rec_hdr(phdr, line, cap_int, &cap_dir, cap_dst, err, err_info); if (pkt_len == -1) return FALSE; if (!parse_netscreen_hex_dump(wth->random_fh, pkt_len, cap_int, cap_dst, phdr, buf, err, err_info)) return FALSE; return TRUE; } /* Parses a packet record header. There are a few possible formats: * * XXX list extra formats here! 6843828.0: trust(o) len=98:00121ebbd132->00600868d659/0800 192.168.1.1 -> 192.168.1.10/6 vhl=45, tos=00, id=37739, frag=0000, ttl=64 tlen=84 tcp:ports 2222->2333, seq=3452113890, ack=1540618280, flag=5018/ACK 00 60 08 68 d6 59 00 12 1e bb d1 32 08 00 45 00 .`.h.Y.....2..E. 00 54 93 6b 00 00 40 06 63 dd c0 a8 01 01 c0 a8 .T.k..@.c....... 01 0a 08 ae 09 1d cd c3 13 e2 5b d3 f8 28 50 18 ..........[..(P. 1f d4 79 21 00 00 e7 76 89 64 16 e2 19 0a 80 09 ..y!...v.d...... 31 e7 04 28 04 58 f3 d9 b1 9f 3d 65 1a db d8 61 1..(.X....=e...a 2c 21 b6 d3 20 60 0c 8c 35 98 88 cf 20 91 0e a9 ,!...`..5....... 1d 0b .. */ static int parse_netscreen_rec_hdr(struct wtap_pkthdr *phdr, const char *line, char *cap_int, gboolean *cap_dir, char *cap_dst, int *err, gchar **err_info) { int sec; int dsec, pkt_len; char direction[2]; char cap_src[13]; phdr->rec_type = REC_TYPE_PACKET; phdr->presence_flags = WTAP_HAS_TS|WTAP_HAS_CAP_LEN; if (sscanf(line, "%9d.%9d: %15[a-z0-9/:.-](%1[io]) len=%9d:%12s->%12s/", &sec, &dsec, cap_int, direction, &pkt_len, cap_src, cap_dst) < 5) { *err = WTAP_ERR_BAD_FILE; *err_info = g_strdup("netscreen: Can't parse packet-header"); return -1; } *cap_dir = (direction[0] == 'o' ? NETSCREEN_EGRESS : NETSCREEN_INGRESS); phdr->ts.secs = sec; phdr->ts.nsecs = dsec * 100000000; phdr->len = pkt_len; return pkt_len; } /* Converts ASCII hex dump to binary data, and fills in some struct wtap_pkthdr fields. Returns TRUE on success and FALSE on any error. */ static gboolean parse_netscreen_hex_dump(FILE_T fh, int pkt_len, const char *cap_int, const char *cap_dst, struct wtap_pkthdr *phdr, Buffer* buf, int *err, gchar **err_info) { guint8 *pd; gchar line[NETSCREEN_LINE_LENGTH]; gchar *p; int n, i = 0, offset = 0; gchar dststr[13]; /* Make sure we have enough room for the packet */ ws_buffer_assure_space(buf, NETSCREEN_MAX_PACKET_LEN); pd = ws_buffer_start_ptr(buf); while(1) { /* The last packet is not delimited by an empty line, but by EOF * So accept EOF as a valid delimiter too */ if (file_gets(line, NETSCREEN_LINE_LENGTH, fh) == NULL) { break; } /* * Skip blanks. * The number of blanks is not fixed - for wireless * interfaces, there may be 14 extra spaces before * the hex data. */ for (p = &line[0]; g_ascii_isspace(*p); p++) ; /* packets are delimited with empty lines */ if (*p == '\0') { break; } n = parse_single_hex_dump_line(p, pd, offset); /* the smallest packet has a length of 6 bytes, if * the first hex-data is less then check whether * it is a info-line and act accordingly */ if (offset == 0 && n < 6) { if (info_line(line)) { if (++i <= NETSCREEN_MAX_INFOLINES) { continue; } } else { *err = WTAP_ERR_BAD_FILE; *err_info = g_strdup("netscreen: cannot parse hex-data"); return FALSE; } } /* If there is no more data and the line was not empty, * then there must be an error in the file */ if(n == -1) { *err = WTAP_ERR_BAD_FILE; *err_info = g_strdup("netscreen: cannot parse hex-data"); return FALSE; } /* Adjust the offset to the data that was just added to the buffer */ offset += n; /* If there was more hex-data than was announced in the len=x * header, then then there must be an error in the file */ if(offset > pkt_len) { *err = WTAP_ERR_BAD_FILE; *err_info = g_strdup("netscreen: too much hex-data"); return FALSE; } } /* * Determine the encapsulation type, based on the * first 4 characters of the interface name * * XXX convert this to a 'case' structure when adding more * (non-ethernet) interfacetypes */ if (strncmp(cap_int, "adsl", 4) == 0) { /* The ADSL interface can be bridged with or without * PPP encapsulation. Check whether the first six bytes * of the hex data are the same as the destination mac * address in the header. If they are, assume ethernet * LinkLayer or else PPP */ g_snprintf(dststr, 13, "%02x%02x%02x%02x%02x%02x", pd[0], pd[1], pd[2], pd[3], pd[4], pd[5]); if (strncmp(dststr, cap_dst, 12) == 0) phdr->pkt_encap = WTAP_ENCAP_ETHERNET; else phdr->pkt_encap = WTAP_ENCAP_PPP; } else if (strncmp(cap_int, "seri", 4) == 0) phdr->pkt_encap = WTAP_ENCAP_PPP; else phdr->pkt_encap = WTAP_ENCAP_ETHERNET; phdr->caplen = offset; return TRUE; } /* Take a string representing one line from a hex dump, with leading white * space removed, and converts the text to binary data. We place the bytes * in the buffer at the specified offset. * * Returns number of bytes successfully read, -1 if bad. */ static int parse_single_hex_dump_line(char* rec, guint8 *buf, guint byte_offset) { int num_items_scanned; guint8 character; guint8 byte; for (num_items_scanned = 0; num_items_scanned < 16; num_items_scanned++) { character = *rec++; if (character >= '0' && character <= '9') byte = character - '0' + 0; else if (character >= 'A' && character <= 'F') byte = character - 'A' + 0xA; else if (character >= 'a' && character <= 'f') byte = character - 'a' + 0xa; else if (character == ' ' || character == '\r' || character == '\n' || character == '\0') { /* Nothing more to parse */ break; } else return -1; /* not a hex digit, space before ASCII dump, or EOL */ byte <<= 4; character = *rec++ & 0xFF; if (character >= '0' && character <= '9') byte += character - '0' + 0; else if (character >= 'A' && character <= 'F') byte += character - 'A' + 0xA; else if (character >= 'a' && character <= 'f') byte += character - 'a' + 0xa; else return -1; /* not a hex digit */ buf[byte_offset + num_items_scanned] = byte; character = *rec++ & 0xFF; if (character == '\0' || character == '\r' || character == '\n') { /* Nothing more to parse */ break; } else if (character != ' ') { /* not space before ASCII dump */ return -1; } } if (num_items_scanned == 0) return -1; return num_items_scanned; } /* * Editor modelines - http://www.wireshark.org/tools/modelines.html * * Local variables: * c-basic-offset: 8 * tab-width: 8 * indent-tabs-mode: t * End: * * vi: set shiftwidth=8 tabstop=8 noexpandtab: * :indentSize=8:tabSize=8:noTabs=false: */