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-rw-r--r--libkmod/libkmod-file.c209
1 files changed, 86 insertions, 123 deletions
diff --git a/libkmod/libkmod-file.c b/libkmod/libkmod-file.c
index b138e7e..8baf12d 100644
--- a/libkmod/libkmod-file.c
+++ b/libkmod/libkmod-file.c
@@ -41,27 +41,12 @@
#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;
+ int (*load)(struct kmod_file *file);
const struct kmod_ctx *ctx;
struct kmod_elf *elf;
};
@@ -179,7 +164,6 @@ static int load_zstd(struct kmod_file *file)
ZSTD_freeDStream(dstr);
free((void *)zst_inb.src);
- file->zstd_used = true;
file->memory = zst_outb.dst;
file->size = zst_outb.pos;
return 0;
@@ -190,16 +174,14 @@ out:
free((void *)zst_outb.dst);
return ret;
}
-
-static void unload_zstd(struct kmod_file *file)
+#else
+static int load_zstd(struct kmod_file *file)
{
- if (!file->zstd_used)
- return;
- free(file->memory);
+ return -ENOSYS;
}
+#endif
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)
@@ -272,7 +254,6 @@ static int xz_uncompress(lzma_stream *strm, struct kmod_file *file)
goto out;
}
}
- file->xz_used = true;
file->memory = p;
file->size = total;
return 0;
@@ -299,16 +280,14 @@ static int load_xz(struct kmod_file *file)
lzma_end(&strm);
return ret;
}
-
-static void unload_xz(struct kmod_file *file)
+#else
+static int load_xz(struct kmod_file *file)
{
- if (!file->xz_used)
- return;
- free(file->memory);
+ return -ENOSYS;
}
+#endif
static const char magic_xz[] = {0xfd, '7', 'z', 'X', 'Z', 0};
-#endif
#ifdef ENABLE_ZLIB
#define READ_STEP (4 * 1024 * 1024)
@@ -317,12 +296,19 @@ static int load_zlib(struct kmod_file *file)
int err = 0;
off_t did = 0, total = 0;
_cleanup_free_ unsigned char *p = NULL;
+ gzFile gzf;
+ int gzfd;
errno = 0;
- file->gzf = gzdopen(file->fd, "rb");
- if (file->gzf == NULL)
+ gzfd = fcntl(file->fd, F_DUPFD_CLOEXEC, 3);
+ if (gzfd < 0)
return -errno;
- file->fd = -1; /* now owned by gzf due gzdopen() */
+
+ gzf = gzdopen(gzfd, "rb"); /* takes ownership of the fd */
+ if (gzf == NULL) {
+ close(gzfd);
+ return -errno;
+ }
for (;;) {
int r;
@@ -337,12 +323,12 @@ static int load_zlib(struct kmod_file *file)
p = tmp;
}
- r = gzread(file->gzf, p + did, total - did);
+ r = gzread(gzf, p + did, total - did);
if (r == 0)
break;
else if (r < 0) {
int gzerr;
- const char *gz_errmsg = gzerror(file->gzf, &gzerr);
+ const char *gz_errmsg = gzerror(gzf, &gzerr);
ERR(file->ctx, "gzip: %s\n", gz_errmsg);
@@ -356,41 +342,21 @@ static int load_zlib(struct kmod_file *file)
file->memory = p;
file->size = did;
p = NULL;
+ gzclose(gzf);
return 0;
error:
- gzclose(file->gzf);
+ gzclose(gzf); /* closes the gzfd */
return err;
}
-
-static void unload_zlib(struct kmod_file *file)
+#else
+static int load_zlib(struct kmod_file *file)
{
- if (file->gzf == NULL)
- return;
- free(file->memory);
- gzclose(file->gzf); /* closes file->fd */
+ return -ENOSYS;
}
-
-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 const char magic_zlib[] = {0x1f, 0x8b};
static int load_reg(struct kmod_file *file)
{
@@ -402,27 +368,39 @@ static int load_reg(struct kmod_file *file)
file->size = st.st_size;
file->memory = mmap(NULL, file->size, PROT_READ, MAP_PRIVATE,
file->fd, 0);
- if (file->memory == MAP_FAILED)
+ if (file->memory == MAP_FAILED) {
+ file->memory = NULL;
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
+static const struct comp_type {
+ size_t magic_size;
+ enum kmod_file_compression_type compression;
+ const char *magic_bytes;
+ int (*load)(struct kmod_file *file);
+} comp_types[] = {
+ {sizeof(magic_zstd), KMOD_FILE_COMPRESSION_ZSTD, magic_zstd, load_zstd},
+ {sizeof(magic_xz), KMOD_FILE_COMPRESSION_XZ, magic_xz, load_xz},
+ {sizeof(magic_zlib), KMOD_FILE_COMPRESSION_ZLIB, magic_zlib, load_zlib},
+ {0, KMOD_FILE_COMPRESSION_NONE, NULL, load_reg}
};
struct kmod_elf *kmod_file_get_elf(struct kmod_file *file)
{
+ int err;
+
if (file->elf)
return file->elf;
- kmod_file_load_contents(file);
+ err = kmod_file_load_contents(file);
+ if (err) {
+ errno = err;
+ return NULL;
+ }
+
file->elf = kmod_elf_new(file->memory, file->size);
return file->elf;
}
@@ -430,81 +408,63 @@ struct kmod_elf *kmod_file_get_elf(struct kmod_file *file)
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;
+ struct kmod_file *file;
+ char buf[7];
+ ssize_t sz;
+ assert_cc(sizeof(magic_zstd) < sizeof(buf));
+ assert_cc(sizeof(magic_xz) < sizeof(buf));
+ assert_cc(sizeof(magic_zlib) < sizeof(buf));
+
+ file = calloc(1, sizeof(struct kmod_file));
if (file == NULL)
return NULL;
file->fd = open(filename, O_RDONLY|O_CLOEXEC);
if (file->fd < 0) {
- err = -errno;
- goto error;
+ free(file);
+ return NULL;
}
- for (itr = comp_types; itr->ops.load != NULL; itr++) {
- if (magic_size_max < itr->magic_size)
- magic_size_max = itr->magic_size;
- }
+ sz = read_str_safe(file->fd, buf, sizeof(buf));
+ lseek(file->fd, 0, SEEK_SET);
+ if (sz != (sizeof(buf) - 1)) {
+ if (sz < 0)
+ errno = -sz;
+ else
+ errno = EINVAL;
- if (magic_size_max > 0) {
- char *buf = alloca(magic_size_max + 1);
- ssize_t sz;
+ close(file->fd);
+ free(file);
+ return NULL;
+ }
- 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 (unsigned int i = 0; i < ARRAY_SIZE(comp_types); i++) {
+ const struct comp_type *itr = &comp_types[i];
- 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;
- }
+ file->load = itr->load;
+ file->compression = itr->compression;
+ if (itr->magic_size &&
+ memcmp(buf, itr->magic_bytes, itr->magic_size) == 0) {
+ break;
}
}
- if (file->ops == NULL) {
- file->ops = &reg_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)
+int kmod_file_load_contents(struct kmod_file *file)
{
if (file->memory)
- return;
+ return 0;
/* The load functions already log possible errors. */
- file->ops->load(file);
+ return file->load(file);
}
void *kmod_file_get_contents(const struct kmod_file *file)
@@ -532,10 +492,13 @@ 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->compression == KMOD_FILE_COMPRESSION_NONE) {
+ if (file->memory)
+ munmap(file->memory, file->size);
+ } else {
+ free(file->memory);
+ }
- if (file->fd >= 0)
- close(file->fd);
+ close(file->fd);
free(file);
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-25 13:28:25 +0000