diff options
Diffstat (limited to 'kexec/lzma.c')
| -rw-r--r-- | kexec/lzma.c | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/kexec/lzma.c b/kexec/lzma.c new file mode 100644 index 0000000..2fc07e6 --- /dev/null +++ b/kexec/lzma.c @@ -0,0 +1,253 @@ +#include <unistd.h> +#include <sys/types.h> + +#include "kexec-lzma.h" +#include "config.h" +#include "kexec.h" + +#ifdef HAVE_LIBLZMA +#define _GNU_SOURCE +#include <stdio.h> +#include <stdarg.h> +#include <string.h> +#include <stdlib.h> +#include <errno.h> +#include <limits.h> +#include <sys/stat.h> +#include <ctype.h> +#include <lzma.h> + +#define kBufferSize (1 << 15) + +typedef struct lzfile { + uint8_t buf[kBufferSize]; + lzma_stream strm; + FILE *file; + int encoding; + int eof; +} LZFILE; + +LZFILE *lzopen(const char *path, const char *mode); +int lzclose(LZFILE *lzfile); +ssize_t lzread(LZFILE *lzfile, void *buf, size_t len); + +static LZFILE *lzopen_internal(const char *path, const char *mode, int fd) +{ + int level = 5; + int encoding = 0; + FILE *fp; + LZFILE *lzfile; + lzma_ret ret; + lzma_stream lzma_strm_tmp = LZMA_STREAM_INIT; + + for (; *mode; mode++) { + if (*mode == 'w') + encoding = 1; + else if (*mode == 'r') + encoding = 0; + else if (*mode >= '1' && *mode <= '9') + level = *mode - '0'; + } + if (fd != -1) + fp = fdopen(fd, encoding ? "w" : "r"); + else + fp = fopen(path, encoding ? "w" : "r"); + if (!fp) + return NULL; + + lzfile = calloc(1, sizeof(*lzfile)); + + if (!lzfile) { + fclose(fp); + return NULL; + } + + lzfile->file = fp; + lzfile->encoding = encoding; + lzfile->eof = 0; + lzfile->strm = lzma_strm_tmp; + if (encoding) { + lzma_options_lzma opt_lzma; + if (lzma_lzma_preset(&opt_lzma, level - 1)) + return NULL; + ret = lzma_alone_encoder(&lzfile->strm, &opt_lzma); + } else { + ret = lzma_auto_decoder(&lzfile->strm, + UINT64_C(64) * 1024 * 1024, 0); + } + if (ret != LZMA_OK) { + fclose(fp); + free(lzfile); + return NULL; + } + return lzfile; +} + +LZFILE *lzopen(const char *path, const char *mode) +{ + return lzopen_internal(path, mode, -1); +} + +int lzclose(LZFILE *lzfile) +{ + lzma_ret ret; + size_t n; + + if (!lzfile) + return -1; + + if (lzfile->encoding) { + for (;;) { + lzfile->strm.avail_out = kBufferSize; + lzfile->strm.next_out = lzfile->buf; + ret = lzma_code(&lzfile->strm, LZMA_FINISH); + if (ret != LZMA_OK && ret != LZMA_STREAM_END) + return -1; + n = kBufferSize - lzfile->strm.avail_out; + if (n && fwrite(lzfile->buf, 1, n, lzfile->file) != n) + return -1; + if (ret == LZMA_STREAM_END) + break; + } + } + lzma_end(&lzfile->strm); + + return fclose(lzfile->file); + free(lzfile); +} + +ssize_t lzread(LZFILE *lzfile, void *buf, size_t len) +{ + lzma_ret ret; + int eof = 0; + + if (!lzfile || lzfile->encoding) + return -1; + + if (lzfile->eof) + return 0; + + lzfile->strm.next_out = buf; + lzfile->strm.avail_out = len; + + for (;;) { + if (!lzfile->strm.avail_in) { + lzfile->strm.next_in = lzfile->buf; + lzfile->strm.avail_in = fread(lzfile->buf, 1, kBufferSize, lzfile->file); + if (!lzfile->strm.avail_in) + eof = 1; + } + + ret = lzma_code(&lzfile->strm, LZMA_RUN); + if (ret == LZMA_STREAM_END) { + lzfile->eof = 1; + return len - lzfile->strm.avail_out; + } + + if (ret != LZMA_OK) + return -1; + + if (!lzfile->strm.avail_out) + return len; + + if (eof) + return -1; + } +} + +int is_lzma_file(const char *filename) +{ + FILE *fp; + int ret = 0; + uint8_t buf[13]; + + if (!filename) + return 0; + + fp = fopen(filename, "r"); + if (fp == NULL) + return 0; + + const size_t size = fread(buf, 1, sizeof(buf), fp); + + if (size != 13) { + /* file is too small to be a lzma file. */ + fclose(fp); + return 0; + } + + lzma_filter filter = { .id = LZMA_FILTER_LZMA1 }; + + switch (lzma_properties_decode(&filter, NULL, buf, 5)) { + case LZMA_OK: + ret = 1; + break; + default: + /* It's not a lzma file */ + ret = 0; + } + + fclose(fp); + return ret; +} + +char *lzma_decompress_file(const char *filename, off_t *r_size) +{ + LZFILE *fp; + char *buf; + off_t size, allocated; + ssize_t result; + + dbgprintf("Try LZMA decompression.\n"); + + *r_size = 0; + if (!filename) + return NULL; + + if (!is_lzma_file(filename)) + return NULL; + + fp = lzopen(filename, "rb"); + if (fp == 0) { + dbgprintf("Cannot open `%s'\n", filename); + return NULL; + } + size = 0; + allocated = 65536; + buf = xmalloc(allocated); + do { + if (size == allocated) { + allocated <<= 1; + buf = xrealloc(buf, allocated); + } + result = lzread(fp, buf + size, allocated - size); + if (result < 0) { + if ((errno == EINTR) || (errno == EAGAIN)) + continue; + + dbgprintf("%s: read on %s of %ld bytes failed\n", + __func__, filename, (allocated - size) + 0UL); + break; + } + size += result; + } while (result > 0); + + if (lzclose(fp) != LZMA_OK) { + dbgprintf("%s: Close of %s failed\n", __func__, filename); + goto fail; + } + if (result < 0) + goto fail; + + *r_size = size; + return buf; +fail: + free(buf); + return NULL; +} +#else +char *lzma_decompress_file(const char *UNUSED(filename), off_t *UNUSED(r_size)) +{ + return NULL; +} +#endif /* HAVE_LIBLZMA */ |