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#include "system.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <rpmlib.h>
#include "rpmts.h"
#include "rpmlock.h"
/* Internal interface */
#define RPMLOCK_FILE "/var/lib/rpm/transaction.lock"
enum {
RPMLOCK_READ = 1 << 0,
RPMLOCK_WRITE = 1 << 1,
RPMLOCK_WAIT = 1 << 2,
};
typedef struct {
int fd;
int openmode;
} rpmlock;
static rpmlock *rpmlock_new(const char *rootdir)
{
rpmlock *lock = (rpmlock *)malloc(sizeof(rpmlock));
if (lock) {
mode_t oldmask = umask(022);
char *path = (char *)malloc(strlen(rootdir)+
strlen(RPMLOCK_FILE)+2);
if (!path) {
free(lock);
return NULL;
}
sprintf(path, "%s/%s", rootdir, RPMLOCK_FILE);
lock->fd = open(RPMLOCK_FILE, O_RDWR|O_CREAT, 0644);
umask(oldmask);
if (lock->fd == -1) {
lock->fd = open(RPMLOCK_FILE, O_RDONLY);
if (lock->fd == -1) {
free(lock);
lock = NULL;
} else {
lock->openmode = RPMLOCK_READ;
}
} else {
lock->openmode = RPMLOCK_WRITE | RPMLOCK_READ;
}
}
return lock;
}
static void rpmlock_free(rpmlock *lock)
{
if (lock) {
close(lock->fd);
free(lock);
}
}
static int rpmlock_acquire(rpmlock *lock, int mode)
{
int res = 0;
if (lock && (mode & lock->openmode)) {
struct flock info;
int cmd;
if (mode & RPMLOCK_WAIT)
cmd = F_SETLKW;
else
cmd = F_SETLK;
if (mode & RPMLOCK_READ)
info.l_type = F_RDLCK;
else
info.l_type = F_WRLCK;
info.l_whence = SEEK_SET;
info.l_start = 0;
info.l_len = 0;
if (fcntl(lock->fd, cmd, &info) != -1)
res = 1;
}
return res;
}
static void rpmlock_release(rpmlock *lock)
{
if (lock) {
struct flock info;
info.l_type = F_UNLCK;
info.l_whence = SEEK_SET;
info.l_start = 0;
info.l_len = 0;
fcntl(lock->fd, F_SETLK, &info);
}
}
/* External interface */
void *rpmtsAcquireLock(rpmts ts)
{
const char *rootDir = rpmtsRootDir(ts);
rpmlock *lock;
if (!rootDir)
rootDir = "/";
lock = rpmlock_new(rootDir);
if (!lock) {
rpmMessage(RPMMESS_ERROR, _("can't create transaction lock\n"));
} else if (!rpmlock_acquire(lock, RPMLOCK_WRITE)) {
if (lock->openmode & RPMLOCK_WRITE)
rpmMessage(RPMMESS_WARNING,
_("waiting for transaction lock\n"));
if (!rpmlock_acquire(lock, RPMLOCK_WRITE|RPMLOCK_WAIT)) {
rpmMessage(RPMMESS_ERROR,
_("can't create transaction lock\n"));
rpmlock_free(lock);
lock = NULL;
}
}
return lock;
}
void rpmtsFreeLock(void *lock)
{
rpmlock_release((rpmlock *)lock); /* Not really needed here. */
rpmlock_free((rpmlock *)lock);
}
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