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Diffstat (limited to 'wiretap/file_wrappers.c')
| -rw-r--r-- | wiretap/file_wrappers.c | 2236 |
1 files changed, 2236 insertions, 0 deletions
diff --git a/wiretap/file_wrappers.c b/wiretap/file_wrappers.c new file mode 100644 index 00000000..67979a5b --- /dev/null +++ b/wiretap/file_wrappers.c @@ -0,0 +1,2236 @@ +/* file_wrappers.c + * + * Wiretap Library + * Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu> + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +/* file_access interface based heavily on zlib gzread.c and gzlib.c from zlib + * Copyright (C) 1995-2010 Jean-loup Gailly and Mark Adler + * under licence: + * + * SPDX-License-Identifier: Zlib + * + */ + +#include "config.h" +#include "file_wrappers.h" + +#include <assert.h> +#include <errno.h> +#include <string.h> +#include "wtap-int.h" + +#include <wsutil/file_util.h> + +#ifdef HAVE_ZLIB +#define ZLIB_CONST +#include <zlib.h> +#endif /* HAVE_ZLIB */ + +#ifdef HAVE_ZSTD +#include <zstd.h> +#endif + +#ifdef HAVE_LZ4 +#include <lz4.h> + +#if LZ4_VERSION_NUMBER >= 10703 +#define USE_LZ4 +#include <lz4frame.h> +#endif +#endif + +/* + * See RFC 1952: + * + * https://tools.ietf.org/html/rfc1952 + * + * for a description of the gzip file format. + * + * Some other compressed file formats we might want to support: + * + * XZ format: https://tukaani.org/xz/ + * + * Bzip2 format: https://www.sourceware.org/bzip2/ + * + * Lzip format: https://www.nongnu.org/lzip/ + */ + +/* + * List of compression types supported. + */ +static struct compression_type { + wtap_compression_type type; + const char *extension; + const char *description; +} compression_types[] = { +#ifdef HAVE_ZLIB + { WTAP_GZIP_COMPRESSED, "gz", "gzip compressed" }, +#endif +#ifdef HAVE_ZSTD + { WTAP_ZSTD_COMPRESSED, "zst", "zstd compressed" }, +#endif +#ifdef USE_LZ4 + { WTAP_LZ4_COMPRESSED, "lz4", "lz4 compressed" }, +#endif + { WTAP_UNCOMPRESSED, NULL, NULL } +}; + +static wtap_compression_type file_get_compression_type(FILE_T stream); + +wtap_compression_type +wtap_get_compression_type(wtap *wth) +{ + return file_get_compression_type((wth->fh == NULL) ? wth->random_fh : wth->fh); +} + +const char * +wtap_compression_type_description(wtap_compression_type compression_type) +{ + for (struct compression_type *p = compression_types; + p->type != WTAP_UNCOMPRESSED; p++) { + if (p->type == compression_type) + return p->description; + } + return NULL; +} + +const char * +wtap_compression_type_extension(wtap_compression_type compression_type) +{ + for (struct compression_type *p = compression_types; + p->type != WTAP_UNCOMPRESSED; p++) { + if (p->type == compression_type) + return p->extension; + } + return NULL; +} + +GSList * +wtap_get_all_compression_type_extensions_list(void) +{ + GSList *extensions; + + extensions = NULL; /* empty list, to start with */ + + for (struct compression_type *p = compression_types; + p->type != WTAP_UNCOMPRESSED; p++) + extensions = g_slist_prepend(extensions, (gpointer)p->extension); + + return extensions; +} + +/* #define GZBUFSIZE 8192 */ +#define GZBUFSIZE 4096 + +/* values for wtap_reader compression */ +typedef enum { + UNKNOWN, /* unknown - look for a compression header */ + UNCOMPRESSED, /* uncompressed - copy input directly */ + ZLIB, /* decompress a zlib stream */ + GZIP_AFTER_HEADER, + ZSTD, + LZ4, +} compression_t; + +/* + * We limit the size of our input and output buffers to 2^30 bytes, + * because: + * + * 1) on Windows with MSVC, the return value of _read() is int, + * so the biggest read you can do is INT_MAX, and the biggest + * power of 2 below that is 2^30; + * + * 2) the "avail_in" and "avail_out" values in a z_stream structure + * in zlib are uInts, and those are unsigned ints, and that + * imposes a limit on the buffer size when we're reading a + * gzipped file. + * + * Thus, we use guint for the buffer sizes, offsets, amount available + * from the buffer, etc. + * + * If we want an even bigger buffer for uncompressed data, or for + * some other form of compression, then the guint-sized values should + * be in structure values used only for reading gzipped files, and + * other values should be used for uncompressed data or data + * compressed using other algorithms (e.g., in a union). + */ +#define MAX_READ_BUF_SIZE (1U << 30) + +struct wtap_reader_buf { + guint8 *buf; /* buffer */ + guint8 *next; /* next byte to deliver from buffer */ + guint avail; /* number of bytes available to deliver at next */ +}; + +struct wtap_reader { + int fd; /* file descriptor */ + gint64 raw_pos; /* current position in file (just to not call lseek()) */ + gint64 pos; /* current position in uncompressed data */ + guint size; /* buffer size */ + + struct wtap_reader_buf in; /* input buffer, containing compressed data */ + struct wtap_reader_buf out; /* output buffer, containing uncompressed data */ + + gboolean eof; /* TRUE if end of input file reached */ + gint64 start; /* where the gzip data started, for rewinding */ + gint64 raw; /* where the raw data started, for seeking */ + compression_t compression; /* type of compression, if any */ + compression_t last_compression; /* last known compression type */ + gboolean is_compressed; /* FALSE if completely uncompressed, TRUE otherwise */ + + /* seek request */ + gint64 skip; /* amount to skip (already rewound if backwards) */ + gboolean seek_pending; /* TRUE if seek request pending */ + + /* error information */ + int err; /* error code */ + const char *err_info; /* additional error information string for some errors */ + +#ifdef HAVE_ZLIB + /* zlib inflate stream */ + z_stream strm; /* stream structure in-place (not a pointer) */ + gboolean dont_check_crc; /* TRUE if we aren't supposed to check the CRC */ +#endif + /* fast seeking */ + GPtrArray *fast_seek; + void *fast_seek_cur; +#ifdef HAVE_ZSTD + ZSTD_DCtx *zstd_dctx; +#endif +#ifdef USE_LZ4 + LZ4F_dctx *lz4_dctx; +#endif +}; + +/* Current read offset within a buffer. */ +static guint +offset_in_buffer(struct wtap_reader_buf *buf) +{ + /* buf->next points to the next byte to read, and buf->buf points + to the first byte in the buffer, so the difference between them + is the offset. + + This will fit in an unsigned int, because it can't be bigger + than the size of the buffer, which is an unsigned int. */ + return (guint)(buf->next - buf->buf); +} + +/* Number of bytes of data that are in a buffer. */ +static guint +bytes_in_buffer(struct wtap_reader_buf *buf) +{ + /* buf->next + buf->avail points just past the last byte of data in + the buffer. + Thus, (buf->next + buf->avail) - buf->buf is the number of bytes + of data in the buffer. + + This will fit in an guint, because it can't be bigger + than the size of the buffer, which is a guint. */ + return (guint)((buf->next + buf->avail) - buf->buf); +} + +/* Reset a buffer, discarding all data in the buffer, so we read into + it starting at the beginning. */ +static void +buf_reset(struct wtap_reader_buf *buf) +{ + buf->next = buf->buf; + buf->avail = 0; +} + +static int +buf_read(FILE_T state, struct wtap_reader_buf *buf) +{ + guint space_left, to_read; + unsigned char *read_ptr; + ssize_t ret; + + /* How much space is left at the end of the buffer? + XXX - the output buffer actually has state->size * 2 bytes. */ + space_left = state->size - bytes_in_buffer(buf); + if (space_left == 0) { + /* There's no space left, so we start fresh at the beginning + of the buffer. */ + buf_reset(buf); + + read_ptr = buf->buf; + to_read = state->size; + } else { + /* There's some space left; try to read as much data as we + can into that space. We may get less than that if we're + reading from a pipe or if we're near the end of the file. */ + read_ptr = buf->next + buf->avail; + to_read = space_left; + } + + ret = ws_read(state->fd, read_ptr, to_read); + if (ret < 0) { + state->err = errno; + state->err_info = NULL; + return -1; + } + if (ret == 0) + state->eof = TRUE; + state->raw_pos += ret; + buf->avail += (guint)ret; + return 0; +} + +static int /* gz_avail */ +fill_in_buffer(FILE_T state) +{ + if (state->err != 0) + return -1; + if (!state->eof) { + if (buf_read(state, &state->in) < 0) + return -1; + } + return 0; +} + +#define ZLIB_WINSIZE 32768 + +struct fast_seek_point { + gint64 out; /* corresponding offset in uncompressed data */ + gint64 in; /* offset in input file of first full byte */ + + compression_t compression; + union { + struct { +#ifdef HAVE_INFLATEPRIME + int bits; /* number of bits (1-7) from byte at in - 1, or 0 */ +#endif + unsigned char window[ZLIB_WINSIZE]; /* preceding 32K of uncompressed data */ + + /* be gentle with Z_STREAM_END, 8 bytes more... Another solution would be to comment checks out */ + guint32 adler; + guint32 total_out; + } zlib; + } data; +}; + +struct zlib_cur_seek_point { + unsigned char window[ZLIB_WINSIZE]; /* preceding 32K of uncompressed data */ + unsigned int pos; + unsigned int have; +}; + +#define SPAN G_GINT64_CONSTANT(1048576) +static struct fast_seek_point * +fast_seek_find(FILE_T file, gint64 pos) +{ + struct fast_seek_point *smallest = NULL; + struct fast_seek_point *item; + guint low, i, max; + + if (!file->fast_seek) + return NULL; + + for (low = 0, max = file->fast_seek->len; low < max; ) { + i = (low + max) / 2; + item = (struct fast_seek_point *)file->fast_seek->pdata[i]; + + if (pos < item->out) + max = i; + else if (pos > item->out) { + smallest = item; + low = i + 1; + } else { + return item; + } + } + return smallest; +} + +static void +fast_seek_header(FILE_T file, gint64 in_pos, gint64 out_pos, + compression_t compression) +{ + struct fast_seek_point *item = NULL; + + if (file->fast_seek->len != 0) + item = (struct fast_seek_point *)file->fast_seek->pdata[file->fast_seek->len - 1]; + + if (!item || item->out < out_pos) { + struct fast_seek_point *val = g_new(struct fast_seek_point,1); + val->in = in_pos; + val->out = out_pos; + val->compression = compression; + + g_ptr_array_add(file->fast_seek, val); + } +} + +static void +fast_seek_reset( +#ifdef HAVE_ZLIB + FILE_T state) +#else + FILE_T state _U_) +#endif +{ +#ifdef HAVE_ZLIB + if (state->compression == ZLIB && state->fast_seek_cur != NULL) { + struct zlib_cur_seek_point *cur = (struct zlib_cur_seek_point *) state->fast_seek_cur; + + cur->have = 0; + } +#endif +} + +#ifdef HAVE_ZLIB + +/* Get next byte from input, or -1 if end or error. + * + * Note: + * + * 1) errors from buf_read(), and thus from fill_in_buffer(), are + * "sticky", and fill_in_buffer() won't do any reading if there's + * an error; + * + * 2) GZ_GETC() returns -1 on an EOF; + * + * so it's safe to make multiple GZ_GETC() calls and only check the + * last one for an error. */ +#define GZ_GETC() ((state->in.avail == 0 && fill_in_buffer(state) == -1) ? -1 : \ + (state->in.avail == 0 ? -1 : \ + (state->in.avail--, *(state->in.next)++))) + +/* Get a one-byte integer and return 0 on success and the value in *ret. + Otherwise -1 is returned, state->err is set, and *ret is not modified. */ +static int +gz_next1(FILE_T state, guint8 *ret) +{ + int ch; + + ch = GZ_GETC(); + if (ch == -1) { + if (state->err == 0) { + /* EOF */ + state->err = WTAP_ERR_SHORT_READ; + state->err_info = NULL; + } + return -1; + } + *ret = ch; + return 0; +} + +/* Get a two-byte little-endian integer and return 0 on success and the value + in *ret. Otherwise -1 is returned, state->err is set, and *ret is not + modified. */ +static int +gz_next2(FILE_T state, guint16 *ret) +{ + guint16 val; + int ch; + + val = GZ_GETC(); + ch = GZ_GETC(); + if (ch == -1) { + if (state->err == 0) { + /* EOF */ + state->err = WTAP_ERR_SHORT_READ; + state->err_info = NULL; + } + return -1; + } + val += (guint16)ch << 8; + *ret = val; + return 0; +} + +/* Get a four-byte little-endian integer and return 0 on success and the value + in *ret. Otherwise -1 is returned, state->err is set, and *ret is not + modified. */ +static int +gz_next4(FILE_T state, guint32 *ret) +{ + guint32 val; + int ch; + + val = GZ_GETC(); + val += (unsigned)GZ_GETC() << 8; + val += (guint32)GZ_GETC() << 16; + ch = GZ_GETC(); + if (ch == -1) { + if (state->err == 0) { + /* EOF */ + state->err = WTAP_ERR_SHORT_READ; + state->err_info = NULL; + } + return -1; + } + val += (guint32)ch << 24; + *ret = val; + return 0; +} + +/* Skip the specified number of bytes and return 0 on success. Otherwise -1 + is returned. */ +static int +gz_skipn(FILE_T state, size_t n) +{ + while (n != 0) { + if (GZ_GETC() == -1) { + if (state->err == 0) { + /* EOF */ + state->err = WTAP_ERR_SHORT_READ; + state->err_info = NULL; + } + return -1; + } + n--; + } + return 0; +} + +/* Skip a null-terminated string and return 0 on success. Otherwise -1 + is returned. */ +static int +gz_skipzstr(FILE_T state) +{ + int ch; + + /* It's null-terminated, so scan until we read a byte with + the value 0 or get an error. */ + while ((ch = GZ_GETC()) > 0) + ; + if (ch == -1) { + if (state->err == 0) { + /* EOF */ + state->err = WTAP_ERR_SHORT_READ; + state->err_info = NULL; + } + return -1; + } + return 0; +} + +static void +zlib_fast_seek_add(FILE_T file, struct zlib_cur_seek_point *point, int bits, gint64 in_pos, gint64 out_pos) +{ + /* it's for sure after gzip header, so file->fast_seek->len != 0 */ + struct fast_seek_point *item = (struct fast_seek_point *)file->fast_seek->pdata[file->fast_seek->len - 1]; + +#ifndef HAVE_INFLATEPRIME + if (bits) + return; +#endif + + /* Glib has got Balanced Binary Trees (GTree) but I couldn't find a way to do quick search for nearest (and smaller) value to seek (It's what fast_seek_find() do) + * Inserting value in middle of sorted array is expensive, so we want to add only in the end. + * It's not big deal, cause first-read don't usually invoke seeking + */ + if (item->out + SPAN < out_pos) { + struct fast_seek_point *val = g_new(struct fast_seek_point,1); + val->in = in_pos; + val->out = out_pos; + val->compression = ZLIB; +#ifdef HAVE_INFLATEPRIME + val->data.zlib.bits = bits; +#endif + if (point->pos != 0) { + unsigned int left = ZLIB_WINSIZE - point->pos; + + memcpy(val->data.zlib.window, point->window + point->pos, left); + memcpy(val->data.zlib.window + left, point->window, point->pos); + } else + memcpy(val->data.zlib.window, point->window, ZLIB_WINSIZE); + + /* + * XXX - strm.adler is a uLong in at least some versions + * of zlib, and uLong is an unsigned long in at least + * some of those versions, which means it's 64-bit + * on LP64 platforms, even though the checksum is + * 32-bit. We assume the actual Adler checksum + * is in the lower 32 bits of strm.adler; as the + * checksum in the file is only 32 bits, we save only + * those lower 32 bits, and cast away any additional + * bits to squelch warnings. + * + * The same applies to strm.total_out. + */ + val->data.zlib.adler = (guint32) file->strm.adler; + val->data.zlib.total_out = (guint32) file->strm.total_out; + g_ptr_array_add(file->fast_seek, val); + } +} + +static void /* gz_decomp */ +zlib_read(FILE_T state, unsigned char *buf, unsigned int count) +{ + int ret = 0; /* XXX */ + guint32 crc, len; + z_streamp strm = &(state->strm); + + unsigned char *buf2 = buf; + unsigned int count2 = count; + + strm->avail_out = count; + strm->next_out = buf; + + /* fill output buffer up to end of deflate stream or error */ + do { + /* get more input for inflate() */ + if (state->in.avail == 0 && fill_in_buffer(state) == -1) + break; + if (state->in.avail == 0) { + /* EOF */ + state->err = WTAP_ERR_SHORT_READ; + state->err_info = NULL; + break; + } + + strm->avail_in = state->in.avail; + strm->next_in = state->in.next; + /* decompress and handle errors */ +#ifdef Z_BLOCK + ret = inflate(strm, Z_BLOCK); +#else + ret = inflate(strm, Z_NO_FLUSH); +#endif + state->in.avail = strm->avail_in; +#ifdef z_const +DIAG_OFF(cast-qual) + state->in.next = (unsigned char *)strm->next_in; +DIAG_ON(cast-qual) +#else + state->in.next = strm->next_in; +#endif + if (ret == Z_STREAM_ERROR) { + state->err = WTAP_ERR_DECOMPRESS; + state->err_info = strm->msg; + break; + } + if (ret == Z_NEED_DICT) { + state->err = WTAP_ERR_DECOMPRESS; + state->err_info = "preset dictionary needed"; + break; + } + if (ret == Z_MEM_ERROR) { + /* This means "not enough memory". */ + state->err = ENOMEM; + state->err_info = NULL; + break; + } + if (ret == Z_DATA_ERROR) { /* deflate stream invalid */ + state->err = WTAP_ERR_DECOMPRESS; + state->err_info = strm->msg; + break; + } + /* + * XXX - Z_BUF_ERROR? + */ + + strm->adler = crc32(strm->adler, buf2, count2 - strm->avail_out); +#ifdef Z_BLOCK + if (state->fast_seek_cur != NULL) { + struct zlib_cur_seek_point *cur = (struct zlib_cur_seek_point *) state->fast_seek_cur; + unsigned int ready = count2 - strm->avail_out; + + if (ready < ZLIB_WINSIZE) { + guint left = ZLIB_WINSIZE - cur->pos; + + if (ready >= left) { + memcpy(cur->window + cur->pos, buf2, left); + if (ready != left) + memcpy(cur->window, buf2 + left, ready - left); + + cur->pos = ready - left; + cur->have += ready; + } else { + memcpy(cur->window + cur->pos, buf2, ready); + cur->pos += ready; + cur->have += ready; + } + + if (cur->have >= ZLIB_WINSIZE) + cur->have = ZLIB_WINSIZE; + + } else { + memcpy(cur->window, buf2 + (ready - ZLIB_WINSIZE), ZLIB_WINSIZE); + cur->pos = 0; + cur->have = ZLIB_WINSIZE; + } + + if (cur->have >= ZLIB_WINSIZE && ret != Z_STREAM_END && (strm->data_type & 128) && !(strm->data_type & 64)) + zlib_fast_seek_add(state, cur, (strm->data_type & 7), state->raw_pos - strm->avail_in, state->pos + (count - strm->avail_out)); + } +#endif + buf2 = (buf2 + count2 - strm->avail_out); + count2 = strm->avail_out; + + } while (strm->avail_out && ret != Z_STREAM_END); + + /* update available output and crc check value */ + state->out.next = buf; + state->out.avail = count - strm->avail_out; + + /* Check gzip trailer if at end of deflate stream. + We don't fail immediately here, we just set an error + indication, so that we try to process what data we + got before the error. The next attempt to read + something past that data will get the error. */ + if (ret == Z_STREAM_END) { + if (gz_next4(state, &crc) != -1 && + gz_next4(state, &len) != -1) { + if (crc != strm->adler && !state->dont_check_crc) { + state->err = WTAP_ERR_DECOMPRESS; + state->err_info = "bad CRC"; + } else if (len != (strm->total_out & 0xffffffffUL)) { + state->err = WTAP_ERR_DECOMPRESS; + state->err_info = "length field wrong"; + } + } + state->last_compression = state->compression; + state->compression = UNKNOWN; /* ready for next stream, once have is 0 */ + g_free(state->fast_seek_cur); + state->fast_seek_cur = NULL; + } +} +#endif + +static int +gz_head(FILE_T state) +{ + guint already_read; + + /* get some data in the input buffer */ + if (state->in.avail == 0) { + if (fill_in_buffer(state) == -1) + return -1; + if (state->in.avail == 0) + return 0; + } + + /* look for the gzip magic header bytes 31 and 139 */ + if (state->in.next[0] == 31) { + state->in.avail--; + state->in.next++; + + /* Make sure the byte after the first byte is present */ + if (state->in.avail == 0 && fill_in_buffer(state) == -1) { + /* Read error. */ + return -1; + } + if (state->in.avail != 0) { + if (state->in.next[0] == 139) { + /* + * We have what looks like the ID1 and ID2 bytes of a gzip + * header. + * Continue processing the file. + * + * XXX - some capture file formats (I'M LOOKING AT YOU, + * ENDACE!) can have 31 in the first byte of the file + * and 139 in the second byte of the file. For now, in + * those cases, you lose. + */ +#ifdef HAVE_ZLIB + guint8 cm; + guint8 flags; + guint16 len; + guint16 hcrc; + + state->in.avail--; + state->in.next++; + + /* read rest of header */ + + /* compression method (CM) */ + if (gz_next1(state, &cm) == -1) + return -1; + if (cm != 8) { + state->err = WTAP_ERR_DECOMPRESS; + state->err_info = "unknown compression method"; + return -1; + } + + /* flags (FLG) */ + if (gz_next1(state, &flags) == -1) { + /* Read error. */ + return -1; + } + if (flags & 0xe0) { /* reserved flag bits */ + state->err = WTAP_ERR_DECOMPRESS; + state->err_info = "reserved flag bits set"; + return -1; + } + + /* modification time (MTIME) */ + if (gz_skipn(state, 4) == -1) { + /* Read error. */ + return -1; + } + + /* extra flags (XFL) */ + if (gz_skipn(state, 1) == -1) { + /* Read error. */ + return -1; + } + + /* operating system (OS) */ + if (gz_skipn(state, 1) == -1) { + /* Read error. */ + return -1; + } + + if (flags & 4) { + /* extra field - get XLEN */ + if (gz_next2(state, &len) == -1) { + /* Read error. */ + return -1; + } + + /* skip the extra field */ + if (gz_skipn(state, len) == -1) { + /* Read error. */ + return -1; + } + } + if (flags & 8) { + /* file name */ + if (gz_skipzstr(state) == -1) { + /* Read error. */ + return -1; + } + } + if (flags & 16) { + /* comment */ + if (gz_skipzstr(state) == -1) { + /* Read error. */ + return -1; + } + } + if (flags & 2) { + /* header crc */ + if (gz_next2(state, &hcrc) == -1) { + /* Read error. */ + return -1; + } + /* XXX - check the CRC? */ + } + + /* set up for decompression */ + inflateReset(&(state->strm)); + state->strm.adler = crc32(0L, Z_NULL, 0); + state->compression = ZLIB; + state->is_compressed = TRUE; +#ifdef Z_BLOCK + if (state->fast_seek) { + struct zlib_cur_seek_point *cur = g_new(struct zlib_cur_seek_point,1); + + cur->pos = cur->have = 0; + g_free(state->fast_seek_cur); + state->fast_seek_cur = cur; + fast_seek_header(state, state->raw_pos - state->in.avail, state->pos, GZIP_AFTER_HEADER); + } +#endif /* Z_BLOCK */ + return 0; +#else /* HAVE_ZLIB */ + state->err = WTAP_ERR_DECOMPRESSION_NOT_SUPPORTED; + state->err_info = "reading gzip-compressed files isn't supported"; + return -1; +#endif /* HAVE_ZLIB */ + } + + /* + * Not a gzip file. "Unget" the first character; either: + * + * 1) we read both of the first two bytes into the + * buffer with the first ws_read, so we can just back + * up by one byte; + * + * 2) we only read the first byte into the buffer with + * the first ws_read (e.g., because we're reading from + * a pipe and only the first byte had been written to + * the pipe at that point), and read the second byte + * into the buffer after the first byte in the + * fill_in_buffer call, so we now have two bytes in + * the buffer, and can just back up by one byte. + */ + state->in.avail++; + state->in.next--; + } + } +#ifdef HAVE_LIBXZ + /* { 0xFD, '7', 'z', 'X', 'Z', 0x00 } */ + /* FD 37 7A 58 5A 00 */ +#endif + + if (state->in.avail >= 4 + && state->in.buf[0] == 0x28 && state->in.buf[1] == 0xb5 + && state->in.buf[2] == 0x2f && state->in.buf[3] == 0xfd) { +#ifdef HAVE_ZSTD + const size_t ret = ZSTD_initDStream(state->zstd_dctx); + if (ZSTD_isError(ret)) { + state->err = WTAP_ERR_DECOMPRESS; + state->err_info = ZSTD_getErrorName(ret); + return -1; + } + + state->compression = ZSTD; + state->is_compressed = TRUE; + return 0; +#else + state->err = WTAP_ERR_DECOMPRESSION_NOT_SUPPORTED; + state->err_info = "reading zstd-compressed files isn't supported"; + return -1; +#endif + } + + if (state->in.avail >= 4 + && state->in.buf[0] == 0x04 && state->in.buf[1] == 0x22 + && state->in.buf[2] == 0x4d && state->in.buf[3] == 0x18) { +#ifdef USE_LZ4 +#if LZ4_VERSION_NUMBER >= 10800 + LZ4F_resetDecompressionContext(state->lz4_dctx); +#else + LZ4F_freeDecompressionContext(state->lz4_dctx); + const LZ4F_errorCode_t ret = LZ4F_createDecompressionContext(&state->lz4_dctx, LZ4F_VERSION); + if (LZ4F_isError(ret)) { + state->err = WTAP_ERR_INTERNAL; + state->err_info = LZ4F_getErrorName(ret); + return -1; + } +#endif + state->compression = LZ4; + state->is_compressed = TRUE; + return 0; +#else + state->err = WTAP_ERR_DECOMPRESSION_NOT_SUPPORTED; + state->err_info = "reading lz4-compressed files isn't supported"; + return -1; +#endif + } + + if (state->fast_seek) + fast_seek_header(state, state->raw_pos - state->in.avail - state->out.avail, state->pos, UNCOMPRESSED); + + /* doing raw i/o, save start of raw data for seeking, copy any leftover + input to output -- this assumes that the output buffer is larger than + the input buffer, which also assures space for gzungetc() */ + state->raw = state->pos; + state->out.next = state->out.buf; + /* not a compressed file -- copy everything we've read into the + input buffer to the output buffer and fall to raw i/o */ + already_read = bytes_in_buffer(&state->in); + if (already_read != 0) { + memcpy(state->out.buf, state->in.buf, already_read); + state->out.avail = already_read; + + /* Now discard everything in the input buffer */ + buf_reset(&state->in); + } + state->compression = UNCOMPRESSED; + return 0; +} + +static int /* gz_make */ +fill_out_buffer(FILE_T state) +{ + if (state->compression == UNKNOWN) { /* look for compression header */ + if (gz_head(state) == -1) + return -1; + if (state->out.avail != 0) /* got some data from gz_head() */ + return 0; + } + if (state->compression == UNCOMPRESSED) { /* straight copy */ + if (buf_read(state, &state->out) < 0) + return -1; + } +#ifdef HAVE_ZLIB + else if (state->compression == ZLIB) { /* decompress */ + zlib_read(state, state->out.buf, state->size << 1); + } +#endif +#ifdef HAVE_ZSTD + else if (state->compression == ZSTD) { + ws_assert(state->out.avail == 0); + + if (state->in.avail == 0 && fill_in_buffer(state) == -1) + return -1; + + ZSTD_outBuffer output = {state->out.buf, state->size << 1, 0}; + ZSTD_inBuffer input = {state->in.next, state->in.avail, 0}; + const size_t ret = ZSTD_decompressStream(state->zstd_dctx, &output, &input); + if (ZSTD_isError(ret)) { + state->err = WTAP_ERR_DECOMPRESS; + state->err_info = ZSTD_getErrorName(ret); + return -1; + } + + state->in.next = state->in.next + input.pos; + state->in.avail -= (guint)input.pos; + + state->out.next = output.dst; + state->out.avail = (guint)output.pos; + + if (ret == 0) { + state->last_compression = state->compression; + state->compression = UNKNOWN; + } + } +#endif +#ifdef USE_LZ4 + else if (state->compression == LZ4) { + ws_assert(state->out.avail == 0); + + if (state->in.avail == 0 && fill_in_buffer(state) == -1) + return -1; + + size_t outBufSize = state->size << 1; + size_t inBufSize = state->in.avail; + const size_t ret = LZ4F_decompress(state->lz4_dctx, state->out.buf, &outBufSize, state->in.next, &inBufSize, NULL); + if (LZ4F_isError(ret)) { + state->err = WTAP_ERR_DECOMPRESS; + state->err_info = LZ4F_getErrorName(ret); + return -1; + } + + /* + * We assume LZ4F_decompress() will not set inBufSize to a + * value > state->in.avail. + */ + state->in.next = state->in.next + inBufSize; + state->in.avail -= (guint)inBufSize; + + state->out.next = state->out.buf; + state->out.avail = (guint)outBufSize; + + if (ret == 0) { + state->last_compression = state->compression; + state->compression = UNKNOWN; + } + } +#endif + return 0; +} + +static int +gz_skip(FILE_T state, gint64 len) +{ + guint n; + + /* skip over len bytes or reach end-of-file, whichever comes first */ + while (len) + if (state->out.avail != 0) { + /* We have stuff in the output buffer; skip over + it. */ + n = (gint64)state->out.avail > len ? (unsigned)len : state->out.avail; + state->out.avail -= n; + state->out.next += n; + state->pos += n; + len -= n; + } else if (state->err != 0) { + /* We have nothing in the output buffer, and + we have an error that may not have been + reported yet; that means we can't generate + any more data into the output buffer, so + return an error indication. */ + return -1; + } else if (state->eof && state->in.avail == 0) { + /* We have nothing in the output buffer, and + we're at the end of the input; just return. */ + break; + } else { + /* We have nothing in the output buffer, and + we can generate more data; get more output, + looking for header if required. */ + if (fill_out_buffer(state) == -1) + return -1; + } + return 0; +} + +static void +gz_reset(FILE_T state) +{ + buf_reset(&state->out); /* no output data available */ + state->eof = FALSE; /* not at end of file */ + state->compression = UNKNOWN; /* look for compression header */ + + state->seek_pending = FALSE; /* no seek request pending */ + state->err = 0; /* clear error */ + state->err_info = NULL; + state->pos = 0; /* no uncompressed data yet */ + buf_reset(&state->in); /* no input data yet */ +} + +FILE_T +file_fdopen(int fd) +{ + /* + * XXX - we now check whether we have st_blksize in struct stat; + * it's not available on all platforms. + * + * I'm not sure why we're testing _STATBUF_ST_BLKSIZE; it's not + * set on all platforms that have st_blksize in struct stat. + * (Not all platforms have st_blksize in struct stat.) + * + * Is there some reason *not* to make the buffer size the maximum + * of GBUFSIZE and st_blksize? On most UN*Xes, the standard I/O + * library does I/O with st_blksize as the buffer size; on others, + * and on Windows, it's a 4K buffer size. If st_blksize is bigger + * than GBUFSIZE (which is currently 4KB), that's probably a + * hint that reading in st_blksize chunks is considered a good + * idea (e.g., an 8K/1K Berkeley fast file system with st_blksize + * being 8K, or APFS, where st_blksize is big on at least some + * versions of macOS). + */ +#ifdef _STATBUF_ST_BLKSIZE + ws_statb64 st; +#endif +#ifdef HAVE_ZSTD + size_t zstd_buf_size; +#endif + guint want = GZBUFSIZE; + FILE_T state; +#ifdef USE_LZ4 + size_t ret; +#endif + + if (fd == -1) + return NULL; + + /* allocate FILE_T structure to return */ + state = (FILE_T)g_try_malloc0(sizeof *state); + if (state == NULL) + return NULL; + + state->fast_seek_cur = NULL; + state->fast_seek = NULL; + + /* open the file with the appropriate mode (or just use fd) */ + state->fd = fd; + + /* we don't yet know whether it's compressed */ + state->is_compressed = FALSE; + state->last_compression = UNKNOWN; + + /* save the current position for rewinding (only if reading) */ + state->start = ws_lseek64(state->fd, 0, SEEK_CUR); + if (state->start == -1) state->start = 0; + state->raw_pos = state->start; + + /* initialize stream */ + gz_reset(state); + +#ifdef _STATBUF_ST_BLKSIZE + /* + * See what I/O size the file system recommends using, and if + * it's bigger than what we're using and isn't too big, use + * it. + */ + if (ws_fstat64(fd, &st) >= 0) { + /* + * Yes, st_blksize can be bigger than an int; apparently, + * it's a long on LP64 Linux, for example. + * + * If the value is too big to fit into a guint, + * just use the maximum read buffer size. + * + * On top of that, the Single UNIX Speification says that + * st_blksize is of type blksize_t, which is a *signed* + * integer type, and, at minimum, macOS 11.6 and Linux 5.14.11's + * include/uapi/asm-generic/stat.h define it as such. + * + * However, other OSes might make it unsigned, and older versions + * of OSes that currently make it signed might make it unsigned, + * so we try to avoid warnings from that. + * + * We cast MAX_READ_BUF_SIZE to long in order to avoid the + * warning, although it might introduce warnings on platforms + * where st_blocksize is unsigned; we'll deal with that if + * it ever shows up as an issue. + * + * MAX_READ_BUF_SIZE is < the largest *signed* 32-bt integer, + * so casting it to long won't turn it into a negative number. + * (We only support 32-bit and 64-bit 2's-complement platforms.) + */ + if (st.st_blksize <= (long)MAX_READ_BUF_SIZE) + want = (guint)st.st_blksize; + else + want = MAX_READ_BUF_SIZE; + /* XXX, verify result? */ + } +#endif +#ifdef HAVE_ZSTD + /* we should have separate input and output buf sizes */ + zstd_buf_size = ZSTD_DStreamInSize(); + if (zstd_buf_size > want) { + if (zstd_buf_size <= MAX_READ_BUF_SIZE) + want = (guint)zstd_buf_size; + else + want = MAX_READ_BUF_SIZE; + } + zstd_buf_size = ZSTD_DStreamOutSize(); + if (zstd_buf_size > want) { + if (zstd_buf_size <= MAX_READ_BUF_SIZE) + want = (guint)zstd_buf_size; + else + want = MAX_READ_BUF_SIZE; + } +#endif + /* allocate buffers */ + state->in.buf = (unsigned char *)g_try_malloc(want); + state->in.next = state->in.buf; + state->in.avail = 0; + state->out.buf = (unsigned char *)g_try_malloc(want << 1); + state->out.next = state->out.buf; + state->out.avail = 0; + state->size = want; + if (state->in.buf == NULL || state->out.buf == NULL) { + goto err; + } + +#ifdef HAVE_ZLIB + /* allocate inflate memory */ + state->strm.zalloc = Z_NULL; + state->strm.zfree = Z_NULL; + state->strm.opaque = Z_NULL; + state->strm.avail_in = 0; + state->strm.next_in = Z_NULL; + if (inflateInit2(&(state->strm), -15) != Z_OK) { /* raw inflate */ + goto err; + } + + /* for now, assume we should check the crc */ + state->dont_check_crc = FALSE; +#endif + +#ifdef HAVE_ZSTD + state->zstd_dctx = ZSTD_createDCtx(); + if (state->zstd_dctx == NULL) { + goto err; + } +#endif + +#ifdef USE_LZ4 + ret = LZ4F_createDecompressionContext(&state->lz4_dctx, LZ4F_VERSION); + if (LZ4F_isError(ret)) { + goto err; + } +#endif + + /* return stream */ + return state; + +err: +#ifdef HAVE_ZLIB + inflateEnd(&state->strm); +#endif +#ifdef HAVE_ZSTD + ZSTD_freeDCtx(state->zstd_dctx); +#endif +#ifdef USE_LZ4 + LZ4F_freeDecompressionContext(state->lz4_dctx); +#endif + g_free(state->out.buf); + g_free(state->in.buf); + g_free(state); + errno = ENOMEM; + return NULL; +} + +FILE_T +file_open(const char *path) +{ + int fd; + FILE_T ft; +#ifdef HAVE_ZLIB + const char *suffixp; +#endif + + /* open file and do correct filename conversions. + + XXX - do we need O_LARGEFILE? On UN*X, if we need to do + something special to get large file support, the configure + script should have set us up with the appropriate #defines, + so we should be getting a large-file-enabled file descriptor + here. Pre-Large File Summit UN*Xes, and possibly even some + post-LFS UN*Xes, might require O_LARGEFILE here, though. + If so, we should probably handle that in ws_open(). */ + if ((fd = ws_open(path, O_RDONLY|O_BINARY, 0000)) == -1) + return NULL; + + /* open file handle */ + ft = file_fdopen(fd); + if (ft == NULL) { + ws_close(fd); + return NULL; + } + +#ifdef HAVE_ZLIB + /* + * If this file's name ends in ".caz", it's probably a compressed + * Windows Sniffer file. The compression is gzip, but if we + * process the CRC as specified by RFC 1952, the computed CRC + * doesn't match the stored CRC. + * + * Compressed Windows Sniffer files don't all have the same CRC + * value; is it just random crap, or are they running the CRC on + * a different set of data than you're supposed to (e.g., not + * CRCing some of the data), or something such as that? + * + * For now, we just set a flag to ignore CRC errors. + */ + suffixp = strrchr(path, '.'); + if (suffixp != NULL) { + if (g_ascii_strcasecmp(suffixp, ".caz") == 0) + ft->dont_check_crc = TRUE; + } +#endif + + return ft; +} + +void +file_set_random_access(FILE_T stream, gboolean random_flag _U_, GPtrArray *seek) +{ + stream->fast_seek = seek; +} + +gint64 +file_seek(FILE_T file, gint64 offset, int whence, int *err) +{ + struct fast_seek_point *here; + guint n; + + if (whence != SEEK_SET && whence != SEEK_CUR && whence != SEEK_END) { + ws_assert_not_reached(); +/* + *err = EINVAL; + return -1; +*/ + } + + /* Normalize offset to a SEEK_CUR specification */ + if (whence == SEEK_END) { + /* Seek relative to the end of the file; given that we might be + reading from a compressed file, we do that by seeking to the + end of the file, making an offset relative to the end of + the file an offset relative to the current position. + + XXX - we don't actually use this yet, but, for uncompressed + files, we could optimize it, if desired, by directly using + ws_lseek64(). */ + if (gz_skip(file, G_MAXINT64) == -1) { + *err = file->err; + return -1; + } + if (offset == 0) { + /* We are done */ + return file->pos; + } + } else if (whence == SEEK_SET) + offset -= file->pos; + else if (file->seek_pending) { + /* There's a forward-skip pending, so file->pos doesn't reflect + the actual file position, it represents the position from + which we're skipping; update the offset to include that. */ + offset += file->skip; + } + file->seek_pending = FALSE; + + /* + * Are we moving at all? + */ + if (offset == 0) { + /* No. Just return the current position. */ + return file->pos; + } + + /* + * Are we seeking backwards? + */ + if (offset < 0) { + /* + * Yes. + * + * Do we have enough data before the current position in the + * buffer that we can seek backwards within the buffer? + */ + if (-offset <= offset_in_buffer(&file->out)) { + /* + * Yes. Adjust appropriately. + * + * offset is negative, so -offset is non-negative, and + * -offset is <= an unsigned and thus fits in an unsigned. + * Get that value and adjust appropriately. + * + * (Casting offset to unsigned makes it positive, which + * is not what we would want, so we cast -offset instead.) + * + * XXX - this won't work with -offset = 2^63, as its + * negative isn't a valid 64-bit integer, but we are + * not at all likely to see files big enough to ever + * see a negative offset that large. + */ + guint adjustment = (unsigned)(-offset); + + file->out.avail += adjustment; + file->out.next -= adjustment; + file->pos -= adjustment; + return file->pos; + } + } else { + /* + * No. Offset is positive; we're seeking forwards. + * + * Do we have enough data after the current position in the + * buffer that we can seek forwards within the buffer? + */ + if (offset < file->out.avail) { + /* + * Yes. Adjust appropriately. + * + * offset is < an unsigned and thus fits in an unsigned, + * so we can cast it to guint safely. + */ + file->out.avail -= (guint)offset; + file->out.next += offset; + file->pos += offset; + return file->pos; + } + } + + /* + * We're not seeking within the buffer. Do we have "fast seek" data + * for the location to which we will be seeking, and is the offset + * outside the span for compressed files or is this an uncompressed + * file? + * + * XXX, profile + */ + if ((here = fast_seek_find(file, file->pos + offset)) && + (offset < 0 || offset > SPAN || here->compression == UNCOMPRESSED)) { + gint64 off, off2; + + /* + * Yes. Use that data to do the seek. + * Note that this will be true only if file_set_random_access() + * has been called on this file, which should never be the case + * for a pipe. + */ +#ifdef HAVE_ZLIB + if (here->compression == ZLIB) { +#ifdef HAVE_INFLATEPRIME + off = here->in - (here->data.zlib.bits ? 1 : 0); +#else + off = here->in; +#endif + off2 = here->out; + } else if (here->compression == GZIP_AFTER_HEADER) { + off = here->in; + off2 = here->out; + } else +#endif + { + off2 = (file->pos + offset); + off = here->in + (off2 - here->out); + } + + if (ws_lseek64(file->fd, off, SEEK_SET) == -1) { + *err = errno; + return -1; + } + fast_seek_reset(file); + + file->raw_pos = off; + buf_reset(&file->out); + file->eof = FALSE; + file->seek_pending = FALSE; + file->err = 0; + file->err_info = NULL; + buf_reset(&file->in); + +#ifdef HAVE_ZLIB + if (here->compression == ZLIB) { + z_stream *strm = &file->strm; + + inflateReset(strm); + strm->adler = here->data.zlib.adler; + strm->total_out = here->data.zlib.total_out; +#ifdef HAVE_INFLATEPRIME + if (here->data.zlib.bits) { + FILE_T state = file; + int ret = GZ_GETC(); + + if (ret == -1) { + if (state->err == 0) { + /* EOF */ + *err = WTAP_ERR_SHORT_READ; + } else + *err = state->err; + return -1; + } + (void)inflatePrime(strm, here->data.zlib.bits, ret >> (8 - here->data.zlib.bits)); + } +#endif + (void)inflateSetDictionary(strm, here->data.zlib.window, ZLIB_WINSIZE); + file->compression = ZLIB; + } else if (here->compression == GZIP_AFTER_HEADER) { + z_stream *strm = &file->strm; + + inflateReset(strm); + strm->adler = crc32(0L, Z_NULL, 0); + file->compression = ZLIB; + } else +#endif + file->compression = here->compression; + + offset = (file->pos + offset) - off2; + file->pos = off2; + /* g_print("OK! %ld\n", offset); */ + + if (offset) { + /* Don't skip forward yet, wait until we want to read from + the file; that way, if we do multiple seeks in a row, + all involving forward skips, they will be combined. */ + file->seek_pending = TRUE; + file->skip = offset; + } + return file->pos + offset; + } + + /* + * Is this an uncompressed file, are we within the raw area, + * are we either seeking backwards or seeking past the end + * of the buffer, and are we set up for random access with + * file_set_random_access()? + * + * Again, note that this will never be true on a pipe, as + * file_set_random_access() should never be called if we're + * reading from a pipe. + */ + if (file->compression == UNCOMPRESSED && file->pos + offset >= file->raw + && (offset < 0 || offset >= file->out.avail) + && (file->fast_seek != NULL)) + { + /* + * Yes. Just seek there within the file. + */ + if (ws_lseek64(file->fd, offset - file->out.avail, SEEK_CUR) == -1) { + *err = errno; + return -1; + } + file->raw_pos += (offset - file->out.avail); + buf_reset(&file->out); + file->eof = FALSE; + file->seek_pending = FALSE; + file->err = 0; + file->err_info = NULL; + buf_reset(&file->in); + file->pos += offset; + return file->pos; + } + + /* + * Are we seeking backwards? + */ + if (offset < 0) { + /* + * Yes. We have no fast seek data, so we have to rewind and + * seek forward. + * XXX - true only for compressed files. + * + * Calculate the amount to skip forward after rewinding. + */ + offset += file->pos; + if (offset < 0) { /* before start of file! */ + *err = EINVAL; + return -1; + } + /* rewind, then skip to offset */ + + /* back up and start over */ + if (ws_lseek64(file->fd, file->start, SEEK_SET) == -1) { + *err = errno; + return -1; + } + fast_seek_reset(file); + file->raw_pos = file->start; + gz_reset(file); + } + + /* + * Either we're seeking backwards, but have rewound and now need to + * skip forwards, or we're seeking forwards. + * + * Skip what's in output buffer (one less gzgetc() check). + */ + n = (gint64)file->out.avail > offset ? (unsigned)offset : file->out.avail; + file->out.avail -= n; + file->out.next += n; + file->pos += n; + offset -= n; + + /* request skip (if not zero) */ + if (offset) { + /* Don't skip forward yet, wait until we want to read from + the file; that way, if we do multiple seeks in a row, + all involving forward skips, they will be combined. */ + file->seek_pending = TRUE; + file->skip = offset; + } + return file->pos + offset; +} + +gint64 +file_tell(FILE_T stream) +{ + /* return position */ + return stream->pos + (stream->seek_pending ? stream->skip : 0); +} + +gint64 +file_tell_raw(FILE_T stream) +{ + return stream->raw_pos; +} + +int +file_fstat(FILE_T stream, ws_statb64 *statb, int *err) +{ + if (ws_fstat64(stream->fd, statb) == -1) { + if (err != NULL) + *err = errno; + return -1; + } + return 0; +} + +gboolean +file_iscompressed(FILE_T stream) +{ + return stream->is_compressed; +} + +/* Returns a wtap compression type. If we don't know the compression type, + * return WTAP_UNCOMPRESSED, but if our compression state is temporarily + * UNKNOWN because we need to reread compression headers, return the last + * known compression type. + */ +static wtap_compression_type +file_get_compression_type(FILE_T stream) +{ + if (stream->is_compressed) { + switch ((stream->compression == UNKNOWN) ? stream->last_compression : stream->compression) { + + case ZLIB: + case GZIP_AFTER_HEADER: + return WTAP_GZIP_COMPRESSED; + + case ZSTD: + return WTAP_ZSTD_COMPRESSED; + + case LZ4: + return WTAP_LZ4_COMPRESSED; + + case UNCOMPRESSED: + return WTAP_UNCOMPRESSED; + + default: /* UNKNOWN, should never happen if is_compressed is set */ + ws_assert_not_reached(); + return WTAP_UNCOMPRESSED; + } + } + return WTAP_UNCOMPRESSED; +} + +int +file_read(void *buf, unsigned int len, FILE_T file) +{ + guint got, n; + + /* if len is zero, avoid unnecessary operations */ + if (len == 0) + return 0; + + /* process a skip request */ + if (file->seek_pending) { + file->seek_pending = FALSE; + if (gz_skip(file, file->skip) == -1) + return -1; + } + + /* + * Get len bytes to buf, or less than len if at the end; + * if buf is null, just throw the bytes away. + */ + got = 0; + do { + if (file->out.avail != 0) { + /* We have stuff in the output buffer; copy + what we have. */ + n = file->out.avail > len ? len : file->out.avail; + if (buf != NULL) { + memcpy(buf, file->out.next, n); + buf = (char *)buf + n; + } + file->out.next += n; + file->out.avail -= n; + len -= n; + got += n; + file->pos += n; + } else if (file->err != 0) { + /* We have nothing in the output buffer, and + we have an error that may not have been + reported yet; that means we can't generate + any more data into the output buffer, so + return an error indication. */ + return -1; + } else if (file->eof && file->in.avail == 0) { + /* We have nothing in the output buffer, and + we're at the end of the input; just return + with what we've gotten so far. */ + break; + } else { + /* We have nothing in the output buffer, and + we can generate more data; get more output, + looking for header if required, and + keep looping to process the new stuff + in the output buffer. */ + if (fill_out_buffer(file) == -1) + return -1; + } + } while (len); + + return (int)got; +} + +/* + * XXX - this *peeks* at next byte, not a character. + */ +int +file_peekc(FILE_T file) +{ + int ret = 0; + + /* check that we're reading and that there's no error */ + if (file->err != 0) + return -1; + + /* try output buffer (no need to check for skip request) */ + if (file->out.avail != 0) { + return *(file->out.next); + } + + /* process a skip request */ + if (file->seek_pending) { + file->seek_pending = FALSE; + if (gz_skip(file, file->skip) == -1) + return -1; + } + /* if we processed a skip request, there may be data in the buffer, + * or an error could have occurred; likewise if we didn't do seek but + * now call fill_out_buffer, the errors can occur. So we do this while + * loop to check before and after - this is basically the logic from + * file_read() but only for peeking not consuming a byte + */ + while (1) { + if (file->out.avail != 0) { + return *(file->out.next); + } + else if (file->err != 0) { + return -1; + } + else if (file->eof && file->in.avail == 0) { + return -1; + } + else if (fill_out_buffer(file) == -1) { + return -1; + } + } + /* it's actually impossible to get here */ + return ret; +} + +/* + * XXX - this gets a byte, not a character. + */ +int +file_getc(FILE_T file) +{ + unsigned char buf[1]; + int ret; + + /* check that we're reading and that there's no error */ + if (file->err != 0) + return -1; + + /* try output buffer (no need to check for skip request) */ + if (file->out.avail != 0) { + file->out.avail--; + file->pos++; + return *(file->out.next)++; + } + + ret = file_read(buf, 1, file); + return ret < 1 ? -1 : buf[0]; +} + +/* Like file_gets, but returns a pointer to the terminating NUL. */ +char * +file_getsp(char *buf, int len, FILE_T file) +{ + guint left, n; + char *str; + unsigned char *eol; + + /* check parameters */ + if (buf == NULL || len < 1) + return NULL; + + /* check that there's no error */ + if (file->err != 0) + return NULL; + + /* process a skip request */ + if (file->seek_pending) { + file->seek_pending = FALSE; + if (gz_skip(file, file->skip) == -1) + return NULL; + } + + /* copy output bytes up to new line or len - 1, whichever comes first -- + append a terminating zero to the string (we don't check for a zero in + the contents, let the user worry about that) */ + str = buf; + left = (unsigned)len - 1; + if (left) do { + /* assure that something is in the output buffer */ + if (file->out.avail == 0) { + /* We have nothing in the output buffer. */ + if (file->err != 0) { + /* We have an error that may not have + been reported yet; that means we + can't generate any more data into + the output buffer, so return an + error indication. */ + return NULL; + } + if (fill_out_buffer(file) == -1) + return NULL; /* error */ + if (file->out.avail == 0) { /* end of file */ + if (buf == str) /* got bupkus */ + return NULL; + break; /* got something -- return it */ + } + } + + /* look for end-of-line in current output buffer */ + n = file->out.avail > left ? left : file->out.avail; + eol = (unsigned char *)memchr(file->out.next, '\n', n); + if (eol != NULL) + n = (unsigned)(eol - file->out.next) + 1; + + /* copy through end-of-line, or remainder if not found */ + memcpy(buf, file->out.next, n); + file->out.avail -= n; + file->out.next += n; + file->pos += n; + left -= n; + buf += n; + } while (left && eol == NULL); + + /* found end-of-line or out of space -- add a terminator and return + a pointer to it */ + buf[0] = 0; + return buf; +} + +char * +file_gets(char *buf, int len, FILE_T file) +{ + if (!file_getsp(buf, len, file)) return NULL; + return buf; +} + +int +file_eof(FILE_T file) +{ + /* return end-of-file state */ + return (file->eof && file->in.avail == 0 && file->out.avail == 0); +} + +/* + * Routine to return a Wiretap error code (0 for no error, an errno + * for a file error, or a WTAP_ERR_ code for other errors) for an + * I/O stream. Also returns an error string for some errors. + */ +int +file_error(FILE_T fh, gchar **err_info) +{ + if (fh->err!=0 && err_info) { + /* g_strdup() returns NULL for NULL argument */ + *err_info = g_strdup(fh->err_info); + } + return fh->err; +} + +void +file_clearerr(FILE_T stream) +{ + /* clear error and end-of-file */ + stream->err = 0; + stream->err_info = NULL; + stream->eof = FALSE; +} + +void +file_fdclose(FILE_T file) +{ + if (file->fd != -1) + ws_close(file->fd); + file->fd = -1; +} + +gboolean +file_fdreopen(FILE_T file, const char *path) +{ + int fd; + + if ((fd = ws_open(path, O_RDONLY|O_BINARY, 0000)) == -1) + return FALSE; + file->fd = fd; + return TRUE; +} + +void +file_close(FILE_T file) +{ + int fd = file->fd; + + /* free memory and close file */ + if (file->size) { +#ifdef HAVE_ZLIB + inflateEnd(&(file->strm)); +#endif +#ifdef HAVE_ZSTD + ZSTD_freeDCtx(file->zstd_dctx); +#endif +#ifdef USE_LZ4 + LZ4F_freeDecompressionContext(file->lz4_dctx); +#endif + g_free(file->out.buf); + g_free(file->in.buf); + } + g_free(file->fast_seek_cur); + file->err = 0; + file->err_info = NULL; + g_free(file); + /* + * If fd is -1, somebody's done a file_closefd() on us, so + * we don't need to close the FD itself, and shouldn't do + * so. + */ + if (fd != -1) + ws_close(fd); +} + +#ifdef HAVE_ZLIB +/* internal gzip file state data structure for writing */ +struct wtap_writer { + int fd; /* file descriptor */ + gint64 pos; /* current position in uncompressed data */ + guint size; /* buffer size, zero if not allocated yet */ + guint want; /* requested buffer size, default is GZBUFSIZE */ + unsigned char *in; /* input buffer */ + unsigned char *out; /* output buffer (double-sized when reading) */ + unsigned char *next; /* next output data to deliver or write */ + int level; /* compression level */ + int strategy; /* compression strategy */ + int err; /* error code */ + const char *err_info; /* additional error information string for some errors */ + /* zlib deflate stream */ + z_stream strm; /* stream structure in-place (not a pointer) */ +}; + +GZWFILE_T +gzwfile_open(const char *path) +{ + int fd; + GZWFILE_T state; + int save_errno; + + fd = ws_open(path, O_BINARY|O_WRONLY|O_CREAT|O_TRUNC, 0666); + if (fd == -1) + return NULL; + state = gzwfile_fdopen(fd); + if (state == NULL) { + save_errno = errno; + ws_close(fd); + errno = save_errno; + } + return state; +} + +GZWFILE_T +gzwfile_fdopen(int fd) +{ + GZWFILE_T state; + + /* allocate wtap_writer structure to return */ + state = (GZWFILE_T)g_try_malloc(sizeof *state); + if (state == NULL) + return NULL; + state->fd = fd; + state->size = 0; /* no buffers allocated yet */ + state->want = GZBUFSIZE; /* requested buffer size */ + + state->level = Z_DEFAULT_COMPRESSION; + state->strategy = Z_DEFAULT_STRATEGY; + + /* initialize stream */ + state->err = Z_OK; /* clear error */ + state->err_info = NULL; /* clear additional error information */ + state->pos = 0; /* no uncompressed data yet */ + state->strm.avail_in = 0; /* no input data yet */ + + /* return stream */ + return state; +} + +/* Initialize state for writing a gzip file. Mark initialization by setting + state->size to non-zero. Return -1, and set state->err and possibly + state->err_info, on failure; return 0 on success. */ +static int +gz_init(GZWFILE_T state) +{ + int ret; + z_streamp strm = &(state->strm); + + /* allocate input and output buffers */ + state->in = (unsigned char *)g_try_malloc(state->want); + state->out = (unsigned char *)g_try_malloc(state->want); + if (state->in == NULL || state->out == NULL) { + g_free(state->out); + g_free(state->in); + state->err = ENOMEM; + return -1; + } + + /* allocate deflate memory, set up for gzip compression */ + strm->zalloc = Z_NULL; + strm->zfree = Z_NULL; + strm->opaque = Z_NULL; + ret = deflateInit2(strm, state->level, Z_DEFLATED, + 15 + 16, 8, state->strategy); + if (ret != Z_OK) { + g_free(state->out); + g_free(state->in); + if (ret == Z_MEM_ERROR) { + /* This means "not enough memory". */ + state->err = ENOMEM; + } else { + /* This "shouldn't happen". */ + state->err = WTAP_ERR_INTERNAL; + state->err_info = "Unknown error from deflateInit2()"; + } + return -1; + } + + /* mark state as initialized */ + state->size = state->want; + + /* initialize write buffer */ + strm->avail_out = state->size; + strm->next_out = state->out; + state->next = strm->next_out; + return 0; +} + +/* Compress whatever is at avail_in and next_in and write to the output file. + Return -1, and set state->err and possibly state->err_info, if there is + an error writing to the output file; return 0 on success. + flush is assumed to be a valid deflate() flush value. If flush is Z_FINISH, + then the deflate() state is reset to start a new gzip stream. */ +static int +gz_comp(GZWFILE_T state, int flush) +{ + int ret; + ssize_t got; + ptrdiff_t have; + z_streamp strm = &(state->strm); + + /* allocate memory if this is the first time through */ + if (state->size == 0 && gz_init(state) == -1) + return -1; + + /* run deflate() on provided input until it produces no more output */ + ret = Z_OK; + do { + /* write out current buffer contents if full, or if flushing, but if + doing Z_FINISH then don't write until we get to Z_STREAM_END */ + if (strm->avail_out == 0 || (flush != Z_NO_FLUSH && + (flush != Z_FINISH || ret == Z_STREAM_END))) { + have = strm->next_out - state->next; + if (have) { + got = ws_write(state->fd, state->next, (unsigned int)have); + if (got < 0) { + state->err = errno; + return -1; + } + if ((ptrdiff_t)got != have) { + state->err = WTAP_ERR_SHORT_WRITE; + return -1; + } + } + if (strm->avail_out == 0) { + strm->avail_out = state->size; + strm->next_out = state->out; + } + state->next = strm->next_out; + } + + /* compress */ + have = strm->avail_out; + ret = deflate(strm, flush); + if (ret == Z_STREAM_ERROR) { + /* This "shouldn't happen". */ + state->err = WTAP_ERR_INTERNAL; + state->err_info = "Z_STREAM_ERROR from deflate()"; + return -1; + } + have -= strm->avail_out; + } while (have); + + /* if that completed a deflate stream, allow another to start */ + if (flush == Z_FINISH) + deflateReset(strm); + + /* all done, no errors */ + return 0; +} + +/* Write out len bytes from buf. Return 0, and set state->err, on + failure or on an attempt to write 0 bytes (in which case state->err + is Z_OK); return the number of bytes written on success. */ +unsigned +gzwfile_write(GZWFILE_T state, const void *buf, guint len) +{ + guint put = len; + guint n; + z_streamp strm; + + strm = &(state->strm); + + /* check that there's no error */ + if (state->err != Z_OK) + return 0; + + /* if len is zero, avoid unnecessary operations */ + if (len == 0) + return 0; + + /* allocate memory if this is the first time through */ + if (state->size == 0 && gz_init(state) == -1) + return 0; + + /* for small len, copy to input buffer, otherwise compress directly */ + if (len < state->size) { + /* copy to input buffer, compress when full */ + do { + if (strm->avail_in == 0) + strm->next_in = state->in; + n = state->size - strm->avail_in; + if (n > len) + n = len; +#ifdef z_const +DIAG_OFF(cast-qual) + memcpy((Bytef *)strm->next_in + strm->avail_in, buf, n); +DIAG_ON(cast-qual) +#else + memcpy(strm->next_in + strm->avail_in, buf, n); +#endif + strm->avail_in += n; + state->pos += n; + buf = (const char *)buf + n; + len -= n; + if (len && gz_comp(state, Z_NO_FLUSH) == -1) + return 0; + } while (len); + } + else { + /* consume whatever's left in the input buffer */ + if (strm->avail_in != 0 && gz_comp(state, Z_NO_FLUSH) == -1) + return 0; + + /* directly compress user buffer to file */ + strm->avail_in = len; +#ifdef z_const + strm->next_in = (z_const Bytef *)buf; +#else +DIAG_OFF(cast-qual) + strm->next_in = (Bytef *)buf; +DIAG_ON(cast-qual) +#endif + state->pos += len; + if (gz_comp(state, Z_NO_FLUSH) == -1) + return 0; + } + + /* input was all buffered or compressed (put will fit in int) */ + return (int)put; +} + +/* Flush out what we've written so far. Returns -1, and sets state->err, + on failure; returns 0 on success. */ +int +gzwfile_flush(GZWFILE_T state) +{ + /* check that there's no error */ + if (state->err != Z_OK) + return -1; + + /* compress remaining data with Z_SYNC_FLUSH */ + gz_comp(state, Z_SYNC_FLUSH); + if (state->err != Z_OK) + return -1; + return 0; +} + +/* Flush out all data written, and close the file. Returns a Wiretap + error on failure; returns 0 on success. */ +int +gzwfile_close(GZWFILE_T state) +{ + int ret = 0; + + /* flush, free memory, and close file */ + if (gz_comp(state, Z_FINISH) == -1) + ret = state->err; + (void)deflateEnd(&(state->strm)); + g_free(state->out); + g_free(state->in); + state->err = Z_OK; + if (ws_close(state->fd) == -1 && ret == 0) + ret = errno; + g_free(state); + return ret; +} + +int +gzwfile_geterr(GZWFILE_T state) +{ + return state->err; +} +#endif + +/* + * Editor modelines - https://www.wireshark.org/tools/modelines.html + * + * Local variables: + * c-basic-offset: 4 + * tab-width: 8 + * indent-tabs-mode: nil + * End: + * + * vi: set shiftwidth=4 tabstop=8 expandtab: + * :indentSize=4:tabSize=8:noTabs=true: + */ |