[PATCH v3 10/15] gen_init_cpio: move header formatting into function
Taras Kondratiuk
takondra at cisco.com
Fri Feb 16 20:33:46 UTC 2018
CPIO header is generated in multiple places with the same sprintf()
format string. Move formatting into a single function in preparation
to adding a new cpio format.
Signed-off-by: Taras Kondratiuk <takondra at cisco.com>
---
usr/gen_init_cpio.c | 186 ++++++++++++++++++++++++++--------------------------
1 file changed, 92 insertions(+), 94 deletions(-)
diff --git a/usr/gen_init_cpio.c b/usr/gen_init_cpio.c
index 03b21189d58b..7a2a6d85345d 100644
--- a/usr/gen_init_cpio.c
+++ b/usr/gen_init_cpio.c
@@ -64,34 +64,55 @@ static void push_rest(const char *name)
}
}
-static void push_hdr(const char *s)
+struct cpio_header {
+ unsigned int ino;
+ unsigned int mode;
+ uid_t uid;
+ gid_t gid;
+ unsigned int nlink;
+ time_t mtime;
+ size_t filesize;
+ int devmajor;
+ int devminor;
+ int rdevmajor;
+ int rdevminor;
+ size_t namesize;
+ unsigned int check;
+};
+
+static void push_hdr(const struct cpio_header *hdr)
{
+ char s[256];
+
+ sprintf(s, "%s%08X%08X%08lX%08lX%08X%08lX"
+ "%08X%08X%08X%08X%08X%08X%08X",
+ "070701",
+ hdr->ino,
+ hdr->mode,
+ (long)hdr->uid,
+ (long)hdr->gid,
+ hdr->nlink,
+ (long)hdr->mtime,
+ (unsigned int)hdr->filesize,
+ hdr->devmajor,
+ hdr->devminor,
+ hdr->rdevmajor,
+ hdr->rdevminor,
+ (unsigned int)hdr->namesize,
+ hdr->check);
fputs(s, stdout);
offset += 110;
}
static void cpio_trailer(void)
{
- char s[256];
const char name[] = "TRAILER!!!";
+ struct cpio_header hdr = {
+ .nlink = 1,
+ .namesize = strlen(name)+1,
+ };
- sprintf(s, "%s%08X%08X%08lX%08lX%08X%08lX"
- "%08X%08X%08X%08X%08X%08X%08X",
- "070701", /* magic */
- 0, /* ino */
- 0, /* mode */
- (long) 0, /* uid */
- (long) 0, /* gid */
- 1, /* nlink */
- (long) 0, /* mtime */
- 0, /* filesize */
- 0, /* major */
- 0, /* minor */
- 0, /* rmajor */
- 0, /* rminor */
- (unsigned)strlen(name)+1, /* namesize */
- 0); /* chksum */
- push_hdr(s);
+ push_hdr(&hdr);
push_rest(name);
while (offset % 512) {
@@ -103,27 +124,21 @@ static void cpio_trailer(void)
static int cpio_mkslink(const char *name, const char *target,
unsigned int mode, uid_t uid, gid_t gid)
{
- char s[256];
-
if (name[0] == '/')
name++;
- sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
- "%08X%08X%08X%08X%08X%08X%08X",
- "070701", /* magic */
- ino++, /* ino */
- S_IFLNK | mode, /* mode */
- (long) uid, /* uid */
- (long) gid, /* gid */
- 1, /* nlink */
- (long) default_mtime, /* mtime */
- (unsigned)strlen(target)+1, /* filesize */
- 3, /* major */
- 1, /* minor */
- 0, /* rmajor */
- 0, /* rminor */
- (unsigned)strlen(name) + 1,/* namesize */
- 0); /* chksum */
- push_hdr(s);
+ struct cpio_header hdr = {
+ .ino = ino++,
+ .mode = S_IFLNK | mode,
+ .uid = uid,
+ .gid = gid,
+ .nlink = 1,
+ .mtime = default_mtime,
+ .filesize = strlen(target)+1,
+ .devmajor = 3,
+ .devminor = 1,
+ .namesize = strlen(name)+1,
+ };
+ push_hdr(&hdr);
push_string(name);
push_pad();
push_string(target);
@@ -152,27 +167,20 @@ static int cpio_mkslink_line(const char *line)
static int cpio_mkgeneric(const char *name, unsigned int mode,
uid_t uid, gid_t gid)
{
- char s[256];
-
if (name[0] == '/')
name++;
- sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
- "%08X%08X%08X%08X%08X%08X%08X",
- "070701", /* magic */
- ino++, /* ino */
- mode, /* mode */
- (long) uid, /* uid */
- (long) gid, /* gid */
- 2, /* nlink */
- (long) default_mtime, /* mtime */
- 0, /* filesize */
- 3, /* major */
- 1, /* minor */
- 0, /* rmajor */
- 0, /* rminor */
- (unsigned)strlen(name) + 1,/* namesize */
- 0); /* chksum */
- push_hdr(s);
+ struct cpio_header hdr = {
+ .ino = ino++,
+ .mode = mode,
+ .uid = uid,
+ .gid = gid,
+ .nlink = 2,
+ .mtime = default_mtime,
+ .devmajor = 3,
+ .devminor = 1,
+ .namesize = strlen(name)+1,
+ };
+ push_hdr(&hdr);
push_rest(name);
return 0;
}
@@ -241,8 +249,6 @@ static int cpio_mknod(const char *name, unsigned int mode,
uid_t uid, gid_t gid, char dev_type,
unsigned int maj, unsigned int min)
{
- char s[256];
-
if (dev_type == 'b')
mode |= S_IFBLK;
else
@@ -250,23 +256,20 @@ static int cpio_mknod(const char *name, unsigned int mode,
if (name[0] == '/')
name++;
- sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
- "%08X%08X%08X%08X%08X%08X%08X",
- "070701", /* magic */
- ino++, /* ino */
- mode, /* mode */
- (long) uid, /* uid */
- (long) gid, /* gid */
- 1, /* nlink */
- (long) default_mtime, /* mtime */
- 0, /* filesize */
- 3, /* major */
- 1, /* minor */
- maj, /* rmajor */
- min, /* rminor */
- (unsigned)strlen(name) + 1,/* namesize */
- 0); /* chksum */
- push_hdr(s);
+ struct cpio_header hdr = {
+ .ino = ino++,
+ .mode = mode,
+ .uid = uid,
+ .gid = gid,
+ .nlink = 1,
+ .mtime = default_mtime,
+ .devmajor = 3,
+ .devminor = 1,
+ .rdevmajor = maj,
+ .rdevminor = min,
+ .namesize = strlen(name)+1,
+ };
+ push_hdr(&hdr);
push_rest(name);
return 0;
}
@@ -296,7 +299,6 @@ static int cpio_mkfile(const char *name, const char *location,
unsigned int mode, uid_t uid, gid_t gid,
unsigned int nlinks)
{
- char s[256];
char *filebuf = NULL;
struct stat buf;
long size;
@@ -340,23 +342,19 @@ static int cpio_mkfile(const char *name, const char *location,
if (name[0] == '/')
name++;
namesize = strlen(name) + 1;
- sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
- "%08lX%08X%08X%08X%08X%08X%08X",
- "070701", /* magic */
- ino, /* ino */
- mode, /* mode */
- (long) uid, /* uid */
- (long) gid, /* gid */
- nlinks, /* nlink */
- (long) buf.st_mtime, /* mtime */
- size, /* filesize */
- 3, /* major */
- 1, /* minor */
- 0, /* rmajor */
- 0, /* rminor */
- namesize, /* namesize */
- 0); /* chksum */
- push_hdr(s);
+ struct cpio_header hdr = {
+ .ino = ino,
+ .mode = mode,
+ .uid = uid,
+ .gid = gid,
+ .nlink = nlinks,
+ .mtime = buf.st_mtime,
+ .filesize = size,
+ .devmajor = 3,
+ .devminor = 1,
+ .namesize = namesize,
+ };
+ push_hdr(&hdr);
push_string(name);
push_pad();
--
2.10.3.dirty
--
To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
the body of a message to majordomo at vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
More information about the Linux-security-module-archive
mailing list