diff options
Diffstat (limited to 'libkmod/libkmod-file.c')
| -rw-r--r-- | libkmod/libkmod-file.c | 541 |
1 files changed, 541 insertions, 0 deletions
diff --git a/libkmod/libkmod-file.c b/libkmod/libkmod-file.c new file mode 100644 index 0000000..b138e7e --- /dev/null +++ b/libkmod/libkmod-file.c @@ -0,0 +1,541 @@ +/* + * libkmod - interface to kernel module operations + * + * Copyright (C) 2011-2013 ProFUSION embedded systems + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, see <http://www.gnu.org/licenses/>. + */ + +#include <errno.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/mman.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <unistd.h> +#ifdef ENABLE_ZSTD +#include <zstd.h> +#endif +#ifdef ENABLE_XZ +#include <lzma.h> +#endif +#ifdef ENABLE_ZLIB +#include <zlib.h> +#endif + +#include <shared/util.h> + +#include "libkmod.h" +#include "libkmod-internal.h" + +struct kmod_file; +struct file_ops { + int (*load)(struct kmod_file *file); + void (*unload)(struct kmod_file *file); +}; + +struct kmod_file { +#ifdef ENABLE_ZSTD + bool zstd_used; +#endif +#ifdef ENABLE_XZ + bool xz_used; +#endif +#ifdef ENABLE_ZLIB + gzFile gzf; +#endif + int fd; + enum kmod_file_compression_type compression; + off_t size; + void *memory; + const struct file_ops *ops; + const struct kmod_ctx *ctx; + struct kmod_elf *elf; +}; + +#ifdef ENABLE_ZSTD +static int zstd_read_block(struct kmod_file *file, size_t block_size, + ZSTD_inBuffer *input, size_t *input_capacity) +{ + ssize_t rdret; + int ret; + + if (*input_capacity < block_size) { + free((void *)input->src); + input->src = malloc(block_size); + if (input->src == NULL) { + ret = -errno; + ERR(file->ctx, "zstd: %m\n"); + return ret; + } + *input_capacity = block_size; + } + + rdret = read(file->fd, (void *)input->src, block_size); + if (rdret < 0) { + ret = -errno; + ERR(file->ctx, "zstd: %m\n"); + return ret; + } + + input->pos = 0; + input->size = rdret; + return 0; +} + +static int zstd_ensure_outbuffer_space(ZSTD_outBuffer *buffer, size_t min_free) +{ + uint8_t *old_buffer = buffer->dst; + int ret = 0; + + if (buffer->size - buffer->pos >= min_free) + return 0; + + buffer->size += min_free; + buffer->dst = realloc(buffer->dst, buffer->size); + if (buffer->dst == NULL) { + ret = -errno; + free(old_buffer); + } + + return ret; +} + +static int zstd_decompress_block(struct kmod_file *file, ZSTD_DStream *dstr, + ZSTD_inBuffer *input, ZSTD_outBuffer *output, + size_t *next_block_size) +{ + size_t out_buf_min_size = ZSTD_DStreamOutSize(); + int ret = 0; + + do { + ssize_t dsret; + + ret = zstd_ensure_outbuffer_space(output, out_buf_min_size); + if (ret) { + ERR(file->ctx, "zstd: %s\n", strerror(-ret)); + break; + } + + dsret = ZSTD_decompressStream(dstr, output, input); + if (ZSTD_isError(dsret)) { + ret = -EINVAL; + ERR(file->ctx, "zstd: %s\n", ZSTD_getErrorName(dsret)); + break; + } + if (dsret > 0) + *next_block_size = (size_t)dsret; + } while (input->pos < input->size + || output->pos > output->size + || output->size - output->pos < out_buf_min_size); + + return ret; +} + +static int load_zstd(struct kmod_file *file) +{ + ZSTD_DStream *dstr; + size_t next_block_size; + size_t zst_inb_capacity = 0; + ZSTD_inBuffer zst_inb = { 0 }; + ZSTD_outBuffer zst_outb = { 0 }; + int ret; + + dstr = ZSTD_createDStream(); + if (dstr == NULL) { + ret = -EINVAL; + ERR(file->ctx, "zstd: Failed to create decompression stream\n"); + goto out; + } + + next_block_size = ZSTD_initDStream(dstr); + + while (true) { + ret = zstd_read_block(file, next_block_size, &zst_inb, + &zst_inb_capacity); + if (ret != 0) + goto out; + if (zst_inb.size == 0) /* EOF */ + break; + + ret = zstd_decompress_block(file, dstr, &zst_inb, &zst_outb, + &next_block_size); + if (ret != 0) + goto out; + } + + ZSTD_freeDStream(dstr); + free((void *)zst_inb.src); + file->zstd_used = true; + file->memory = zst_outb.dst; + file->size = zst_outb.pos; + return 0; +out: + if (dstr != NULL) + ZSTD_freeDStream(dstr); + free((void *)zst_inb.src); + free((void *)zst_outb.dst); + return ret; +} + +static void unload_zstd(struct kmod_file *file) +{ + if (!file->zstd_used) + return; + free(file->memory); +} + +static const char magic_zstd[] = {0x28, 0xB5, 0x2F, 0xFD}; +#endif + +#ifdef ENABLE_XZ +static void xz_uncompress_belch(struct kmod_file *file, lzma_ret ret) +{ + switch (ret) { + case LZMA_MEM_ERROR: + ERR(file->ctx, "xz: %s\n", strerror(ENOMEM)); + break; + case LZMA_FORMAT_ERROR: + ERR(file->ctx, "xz: File format not recognized\n"); + break; + case LZMA_OPTIONS_ERROR: + ERR(file->ctx, "xz: Unsupported compression options\n"); + break; + case LZMA_DATA_ERROR: + ERR(file->ctx, "xz: File is corrupt\n"); + break; + case LZMA_BUF_ERROR: + ERR(file->ctx, "xz: Unexpected end of input\n"); + break; + default: + ERR(file->ctx, "xz: Internal error (bug)\n"); + break; + } +} + +static int xz_uncompress(lzma_stream *strm, struct kmod_file *file) +{ + uint8_t in_buf[BUFSIZ], out_buf[BUFSIZ]; + lzma_action action = LZMA_RUN; + lzma_ret ret; + void *p = NULL; + size_t total = 0; + + strm->avail_in = 0; + strm->next_out = out_buf; + strm->avail_out = sizeof(out_buf); + + while (true) { + if (strm->avail_in == 0) { + ssize_t rdret = read(file->fd, in_buf, sizeof(in_buf)); + if (rdret < 0) { + ret = -errno; + goto out; + } + strm->next_in = in_buf; + strm->avail_in = rdret; + if (rdret == 0) + action = LZMA_FINISH; + } + ret = lzma_code(strm, action); + if (strm->avail_out == 0 || ret != LZMA_OK) { + size_t write_size = BUFSIZ - strm->avail_out; + char *tmp = realloc(p, total + write_size); + if (tmp == NULL) { + ret = -errno; + goto out; + } + memcpy(tmp + total, out_buf, write_size); + total += write_size; + p = tmp; + strm->next_out = out_buf; + strm->avail_out = BUFSIZ; + } + if (ret == LZMA_STREAM_END) + break; + if (ret != LZMA_OK) { + xz_uncompress_belch(file, ret); + ret = -EINVAL; + goto out; + } + } + file->xz_used = true; + file->memory = p; + file->size = total; + return 0; + out: + free(p); + return ret; +} + +static int load_xz(struct kmod_file *file) +{ + lzma_stream strm = LZMA_STREAM_INIT; + lzma_ret lzret; + int ret; + + lzret = lzma_stream_decoder(&strm, UINT64_MAX, LZMA_CONCATENATED); + if (lzret == LZMA_MEM_ERROR) { + ERR(file->ctx, "xz: %s\n", strerror(ENOMEM)); + return -ENOMEM; + } else if (lzret != LZMA_OK) { + ERR(file->ctx, "xz: Internal error (bug)\n"); + return -EINVAL; + } + ret = xz_uncompress(&strm, file); + lzma_end(&strm); + return ret; +} + +static void unload_xz(struct kmod_file *file) +{ + if (!file->xz_used) + return; + free(file->memory); +} + +static const char magic_xz[] = {0xfd, '7', 'z', 'X', 'Z', 0}; +#endif + +#ifdef ENABLE_ZLIB +#define READ_STEP (4 * 1024 * 1024) +static int load_zlib(struct kmod_file *file) +{ + int err = 0; + off_t did = 0, total = 0; + _cleanup_free_ unsigned char *p = NULL; + + errno = 0; + file->gzf = gzdopen(file->fd, "rb"); + if (file->gzf == NULL) + return -errno; + file->fd = -1; /* now owned by gzf due gzdopen() */ + + for (;;) { + int r; + + if (did == total) { + void *tmp = realloc(p, total + READ_STEP); + if (tmp == NULL) { + err = -errno; + goto error; + } + total += READ_STEP; + p = tmp; + } + + r = gzread(file->gzf, p + did, total - did); + if (r == 0) + break; + else if (r < 0) { + int gzerr; + const char *gz_errmsg = gzerror(file->gzf, &gzerr); + + ERR(file->ctx, "gzip: %s\n", gz_errmsg); + + /* gzip might not set errno here */ + err = gzerr == Z_ERRNO ? -errno : -EINVAL; + goto error; + } + did += r; + } + + file->memory = p; + file->size = did; + p = NULL; + return 0; + +error: + gzclose(file->gzf); + return err; +} + +static void unload_zlib(struct kmod_file *file) +{ + if (file->gzf == NULL) + return; + free(file->memory); + gzclose(file->gzf); /* closes file->fd */ +} + +static const char magic_zlib[] = {0x1f, 0x8b}; +#endif + +static const struct comp_type { + size_t magic_size; + enum kmod_file_compression_type compression; + const char *magic_bytes; + const struct file_ops ops; +} comp_types[] = { +#ifdef ENABLE_ZSTD + {sizeof(magic_zstd), KMOD_FILE_COMPRESSION_ZSTD, magic_zstd, {load_zstd, unload_zstd}}, +#endif +#ifdef ENABLE_XZ + {sizeof(magic_xz), KMOD_FILE_COMPRESSION_XZ, magic_xz, {load_xz, unload_xz}}, +#endif +#ifdef ENABLE_ZLIB + {sizeof(magic_zlib), KMOD_FILE_COMPRESSION_ZLIB, magic_zlib, {load_zlib, unload_zlib}}, +#endif + {0, KMOD_FILE_COMPRESSION_NONE, NULL, {NULL, NULL}} +}; + +static int load_reg(struct kmod_file *file) +{ + struct stat st; + + if (fstat(file->fd, &st) < 0) + return -errno; + + file->size = st.st_size; + file->memory = mmap(NULL, file->size, PROT_READ, MAP_PRIVATE, + file->fd, 0); + if (file->memory == MAP_FAILED) + return -errno; + + return 0; +} + +static void unload_reg(struct kmod_file *file) +{ + munmap(file->memory, file->size); +} + +static const struct file_ops reg_ops = { + load_reg, unload_reg +}; + +struct kmod_elf *kmod_file_get_elf(struct kmod_file *file) +{ + if (file->elf) + return file->elf; + + kmod_file_load_contents(file); + file->elf = kmod_elf_new(file->memory, file->size); + return file->elf; +} + +struct kmod_file *kmod_file_open(const struct kmod_ctx *ctx, + const char *filename) +{ + struct kmod_file *file = calloc(1, sizeof(struct kmod_file)); + const struct comp_type *itr; + size_t magic_size_max = 0; + int err = 0; + + if (file == NULL) + return NULL; + + file->fd = open(filename, O_RDONLY|O_CLOEXEC); + if (file->fd < 0) { + err = -errno; + goto error; + } + + for (itr = comp_types; itr->ops.load != NULL; itr++) { + if (magic_size_max < itr->magic_size) + magic_size_max = itr->magic_size; + } + + if (magic_size_max > 0) { + char *buf = alloca(magic_size_max + 1); + ssize_t sz; + + if (buf == NULL) { + err = -errno; + goto error; + } + sz = read_str_safe(file->fd, buf, magic_size_max + 1); + lseek(file->fd, 0, SEEK_SET); + if (sz != (ssize_t)magic_size_max) { + if (sz < 0) + err = sz; + else + err = -EINVAL; + goto error; + } + + for (itr = comp_types; itr->ops.load != NULL; itr++) { + if (memcmp(buf, itr->magic_bytes, itr->magic_size) == 0) { + file->ops = &itr->ops; + file->compression = itr->compression; + break; + } + } + } + + if (file->ops == NULL) { + file->ops = ®_ops; + file->compression = KMOD_FILE_COMPRESSION_NONE; + } + + file->ctx = ctx; + +error: + if (err < 0) { + if (file->fd >= 0) + close(file->fd); + free(file); + errno = -err; + return NULL; + } + + return file; +} + +/* + * Callers should just check file->memory got updated + */ +void kmod_file_load_contents(struct kmod_file *file) +{ + if (file->memory) + return; + + /* The load functions already log possible errors. */ + file->ops->load(file); +} + +void *kmod_file_get_contents(const struct kmod_file *file) +{ + return file->memory; +} + +off_t kmod_file_get_size(const struct kmod_file *file) +{ + return file->size; +} + +enum kmod_file_compression_type kmod_file_get_compression(const struct kmod_file *file) +{ + return file->compression; +} + +int kmod_file_get_fd(const struct kmod_file *file) +{ + return file->fd; +} + +void kmod_file_unref(struct kmod_file *file) +{ + if (file->elf) + kmod_elf_unref(file->elf); + + if (file->memory) + file->ops->unload(file); + + if (file->fd >= 0) + close(file->fd); + free(file); +} |