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Diffstat (limited to 'wiretap/mime_file.c')
| -rw-r--r-- | wiretap/mime_file.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/wiretap/mime_file.c b/wiretap/mime_file.c new file mode 100644 index 0000000..a3cce0d --- /dev/null +++ b/wiretap/mime_file.c @@ -0,0 +1,229 @@ +/* mime_file.c + * + * MIME file format decoder for the Wiretap library. + * + * This is for use with Wireshark dissectors that handle file + * formats (e.g., because they handle a particular MIME media type). + * It breaks the file into chunks of at most WTAP_MAX_PACKET_SIZE_STANDARD, + * each of which is reported as a packet, so that files larger than + * WTAP_MAX_PACKET_SIZE_STANDARD can be handled by reassembly. + * + * The "MIME file" dissector does the reassembly, and hands the result + * off to heuristic dissectors to try to identify the file's contents. + * + * Wiretap Library + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include "config.h" + +#include <sys/types.h> + +#ifdef HAVE_UNISTD_H +#include <unistd.h> +#endif + +#include <stdlib.h> +#include <string.h> +#include <time.h> + +#include "wtap-int.h" +#include "file_wrappers.h" +#include <wsutil/buffer.h> +#include "mime_file.h" + +typedef struct { + const guint8 *magic; + guint magic_len; +} mime_files_t; + +/* + * Written by Marton Nemeth <nm127@freemail.hu> + * Copyright 2009 Marton Nemeth + * The JPEG specification can be found at: + * + * https://www.w3.org/Graphics/JPEG/itu-t81.pdf + * https://www.itu.int/rec/T-REC-T.81/en (but you have to pay for it) + * + * and the JFIF specification can be found at: + * + * https://www.itu.int/rec/T-REC-T.871-201105-I/en + * https://www.w3.org/Graphics/JPEG/jfif3.pdf + */ +static const guint8 jpeg_jfif_magic[] = { 0xFF, 0xD8, /* SOF */ + 0xFF /* start of the next marker */ + }; + +/* <?xml */ +static const guint8 xml_magic[] = { '<', '?', 'x', 'm', 'l' }; +static const guint8 png_magic[] = { 0x89, 'P', 'N', 'G', '\r', '\n', 0x1A, '\n' }; +static const guint8 gif87a_magic[] = { 'G', 'I', 'F', '8', '7', 'a'}; +static const guint8 gif89a_magic[] = { 'G', 'I', 'F', '8', '9', 'a'}; +static const guint8 elf_magic[] = { 0x7F, 'E', 'L', 'F'}; +static const guint8 tiff_le_magic[] = { 'I', 'I', 42, 0 }; +static const guint8 tiff_be_magic[] = { 'M', 'M', 0, 42 }; +static const guint8 btsnoop_magic[] = { 'b', 't', 's', 'n', 'o', 'o', 'p', 0}; +static const guint8 pcap_magic[] = { 0xA1, 0xB2, 0xC3, 0xD4 }; +static const guint8 pcap_swapped_magic[] = { 0xD4, 0xC3, 0xB2, 0xA1 }; +static const guint8 pcap_nsec_magic[] = { 0xA1, 0xB2, 0x3C, 0x4D }; +static const guint8 pcap_nsec_swapped_magic[] = { 0x4D, 0x3C, 0xB2, 0xA1 }; +static const guint8 pcapng_premagic[] = { 0x0A, 0x0D, 0x0D, 0x0A }; +static const guint8 blf_magic[] = { 'L', 'O', 'G', 'G' }; +static const guint8 autosar_dlt_magic[] = { 'D', 'L', 'T', 0x01 }; +static const guint8 rtpdump_magic[] = { '#', '!', 'r', 't', 'p', 'p', 'l', 'a', 'y', '1', '.', '0', ' ' }; + +/* File does not start with it */ +static const guint8 pcapng_xmagic[] = { 0x1A, 0x2B, 0x3C, 0x4D }; +static const guint8 pcapng_swapped_xmagic[] = { 0x4D, 0x3C, 0x2B, 0x1A }; + +static const mime_files_t magic_files[] = { + { jpeg_jfif_magic, sizeof(jpeg_jfif_magic) }, + { xml_magic, sizeof(xml_magic) }, + { png_magic, sizeof(png_magic) }, + { gif87a_magic, sizeof(gif87a_magic) }, + { gif89a_magic, sizeof(gif89a_magic) }, + { elf_magic, sizeof(elf_magic) }, + { tiff_le_magic, sizeof(tiff_le_magic) }, + { tiff_be_magic, sizeof(tiff_be_magic) }, + { btsnoop_magic, sizeof(btsnoop_magic) }, + { pcap_magic, sizeof(pcap_magic) }, + { pcap_swapped_magic, sizeof(pcap_swapped_magic) }, + { pcap_nsec_magic, sizeof(pcap_nsec_magic) }, + { pcap_nsec_swapped_magic, sizeof(pcap_nsec_swapped_magic) }, + { pcapng_premagic, sizeof(pcapng_premagic) }, + { blf_magic, sizeof(blf_magic) }, + { autosar_dlt_magic, sizeof(autosar_dlt_magic) }, + { rtpdump_magic, sizeof(rtpdump_magic) }, +}; + +#define N_MAGIC_TYPES (sizeof(magic_files) / sizeof(magic_files[0])) + +static int mime_file_type_subtype = -1; + +void register_mime(void); + +wtap_open_return_val +mime_file_open(wtap *wth, int *err, gchar **err_info) +{ + char magic_buf[128]; /* increase buffer size when needed */ + int bytes_read; + gboolean found_file; + /* guint file_ok; */ + guint i; + + guint read_bytes = 12; + + for (i = 0; i < N_MAGIC_TYPES; i++) + read_bytes = MAX(read_bytes, magic_files[i].magic_len); + + read_bytes = (guint)MIN(read_bytes, sizeof(magic_buf)); + bytes_read = file_read(magic_buf, read_bytes, wth->fh); + + if (bytes_read < 0) { + *err = file_error(wth->fh, err_info); + return WTAP_OPEN_ERROR; + } + if (bytes_read == 0) + return WTAP_OPEN_NOT_MINE; + + found_file = FALSE; + for (i = 0; i < N_MAGIC_TYPES; i++) { + if ((guint) bytes_read >= magic_files[i].magic_len && !memcmp(magic_buf, magic_files[i].magic, MIN(magic_files[i].magic_len, (guint) bytes_read))) { + if (!found_file) { + if (magic_files[i].magic == pcapng_premagic) { + if (memcmp(magic_buf + 8, pcapng_xmagic, sizeof(pcapng_xmagic)) && + memcmp(magic_buf + 8, pcapng_swapped_xmagic, sizeof(pcapng_swapped_xmagic))) + continue; + } + found_file = TRUE; + } else + return WTAP_OPEN_NOT_MINE; /* many files matched, bad file */ + } + } + + if (!found_file) + return WTAP_OPEN_NOT_MINE; + + if (file_seek(wth->fh, 0, SEEK_SET, err) == -1) + return WTAP_OPEN_ERROR; + + wth->file_type_subtype = mime_file_type_subtype; + wth->file_encap = WTAP_ENCAP_MIME; + wth->file_tsprec = WTAP_TSPREC_SEC; + wth->subtype_read = wtap_full_file_read; + wth->subtype_seek_read = wtap_full_file_seek_read; + wth->snapshot_length = 0; + + return WTAP_OPEN_MINE; +} + +static const struct supported_block_type mime_blocks_supported[] = { + /* + * This is a file format that we dissect, so we provide + * only one "packet" with the file's contents, and don't + * support any options. + */ + { WTAP_BLOCK_PACKET, ONE_BLOCK_SUPPORTED, NO_OPTIONS_SUPPORTED } +}; + +static const struct file_type_subtype_info mime_info = { + "MIME File Format", "mime", NULL, NULL, + FALSE, BLOCKS_SUPPORTED(mime_blocks_supported), + NULL, NULL, NULL +}; + +/* + * XXX - registered solely for the benefit of Lua scripts that + * look for the file type "JPEG_JFIF"; it may be removed once + * we get rid of wtap_filetypes. + */ +static const struct supported_block_type jpeg_jfif_blocks_supported[] = { + /* + * This is a file format that we dissect, so we provide + * only one "packet" with the file's contents, and don't + * support any options. + */ + { WTAP_BLOCK_PACKET, ONE_BLOCK_SUPPORTED, NO_OPTIONS_SUPPORTED } +}; + +static const struct file_type_subtype_info jpeg_jfif_info = { + "JPEG/JFIF", "jpeg", "jpg", "jpeg;jfif", + FALSE, BLOCKS_SUPPORTED(jpeg_jfif_blocks_supported), + NULL, NULL, NULL +}; + +void register_mime(void) +{ + int jpeg_jfif_file_type_subtype; + + mime_file_type_subtype = wtap_register_file_type_subtype(&mime_info); + + /* + * Obsoleted by "mime", but we want it for the backwards- + * compatibility table for Lua. + */ + jpeg_jfif_file_type_subtype = wtap_register_file_type_subtype(&jpeg_jfif_info); + + /* + * Register names for backwards compatibility with the + * wtap_filetypes table in Lua. + */ + wtap_register_backwards_compatibility_lua_name("MIME", + mime_file_type_subtype); + wtap_register_backwards_compatibility_lua_name("JPEG_JFIF", + jpeg_jfif_file_type_subtype); +} + +/* + * Editor modelines - https://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: + */ |