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authorDimitri Staessens <dimitri@ouroboros.rocks>2023-08-13 16:58:53 +0200
committerSander Vrijders <sander@ouroboros.rocks>2023-08-23 13:09:10 +0200
commitbd0db9cde25c4490e3ef435842f5638b76cc59a1 (patch)
tree468e77301936d30894851e8565b4a48042712af5
parent18d706ca25cba6b3d1c2a2c97562c40a1745b72d (diff)
downloadouroboros-bd0db9cde25c4490e3ef435842f5638b76cc59a1.tar.gz
ouroboros-bd0db9cde25c4490e3ef435842f5638b76cc59a1.zip
lib: Fix lockfile length
Off-by-one error in lockfile file length. Refactor to reduce code duplication. Signed-off-by: Dimitri Staessens <dimitri@ouroboros.rocks> Signed-off-by: Sander Vrijders <sander@ouroboros.rocks>
-rw-r--r--src/lib/lockfile.c94
1 files changed, 39 insertions, 55 deletions
diff --git a/src/lib/lockfile.c b/src/lib/lockfile.c
index 18585417..c5449907 100644
--- a/src/lib/lockfile.c
+++ b/src/lib/lockfile.c
@@ -36,83 +36,69 @@
#include <sys/stat.h>
#define LF_SIZE (sizeof(pid_t))
+#define LF_PROT (PROT_READ | PROT_WRITE)
struct lockfile {
pid_t * pid;
};
-struct lockfile * lockfile_create(void)
+static struct lockfile * __lockfile_open(int oflag)
{
- int fd;
- mode_t mask;
- struct lockfile * lf = malloc(sizeof(*lf));
- if (lf == NULL)
- return NULL;
-
- mask = umask(0);
+ int fd;
+ struct lockfile * lf;
- fd = shm_open(SHM_LOCKFILE_NAME, O_CREAT | O_EXCL | O_RDWR, 0666);
- if (fd == -1) {
- free(lf);
- return NULL;
- }
+ lf = malloc(sizeof(*lf));
+ if (lf == NULL)
+ goto fail_lockfile;
- umask(mask);
+ fd = shm_open(SHM_LOCKFILE_NAME, oflag, 0666);
+ if (fd == -1)
+ goto fail_shm_open;
- if (ftruncate(fd, LF_SIZE - 1) < 0) {
- free(lf);
- return NULL;
- }
+ if ((oflag & O_CREAT) && ftruncate(fd, LF_SIZE) < 0)
+ goto fail_truncate;
- lf->pid = mmap(NULL,
- LF_SIZE, PROT_READ | PROT_WRITE,
- MAP_SHARED,
- fd,
- 0);
+ lf->pid = mmap(NULL, LF_SIZE, LF_PROT, MAP_SHARED, fd, 0);
+ if (lf->pid == MAP_FAILED)
+ goto fail_mmap;
close (fd);
- if (lf->pid == MAP_FAILED) {
- shm_unlink(SHM_LOCKFILE_NAME);
- free(lf);
- return NULL;
- }
-
- *lf->pid = getpid();
-
return lf;
+
+ fail_mmap:
+ shm_unlink(SHM_LOCKFILE_NAME);
+ fail_truncate:
+ close(fd);
+ fail_shm_open:
+ free(lf);
+ fail_lockfile:
+ return NULL;
}
-struct lockfile * lockfile_open(void)
+struct lockfile * lockfile_create(void)
{
- int fd;
- struct lockfile * lf = malloc(sizeof(*lf));
- if (lf == NULL)
- return NULL;
+ struct lockfile * lf;
+ mode_t mask;
- fd = shm_open(SHM_LOCKFILE_NAME, O_RDWR, 0666);
- if (fd < 0) {
- free(lf);
- return NULL;
- }
+ mask = umask(0);
- lf->pid = mmap(NULL,
- LF_SIZE, PROT_READ | PROT_WRITE,
- MAP_SHARED,
- fd,
- 0);
+ lf = __lockfile_open(O_CREAT | O_EXCL | O_RDWR);
+ if (lf == NULL)
+ return NULL;
- close(fd);
+ umask(mask);
- if (lf->pid == MAP_FAILED) {
- shm_unlink(SHM_LOCKFILE_NAME);
- free(lf);
- return NULL;
- }
+ *lf->pid = getpid();
return lf;
}
+struct lockfile * lockfile_open(void)
+{
+ return __lockfile_open(O_RDWR);
+}
+
void lockfile_close(struct lockfile * lf)
{
assert(lf);
@@ -129,11 +115,9 @@ void lockfile_destroy(struct lockfile * lf)
if (getpid() != *lf->pid && kill(*lf->pid, 0) == 0)
return;
- munmap(lf->pid, LF_SIZE);
+ lockfile_close(lf);
shm_unlink(SHM_LOCKFILE_NAME);
-
- free(lf);
}
pid_t lockfile_owner(struct lockfile * lf)