/*
* open_file() -- open and validate file when registering a file segment.
* remember fd in segment struct.
*/
static int
open_file(segment_t *segp)
{
glctx_t *gcp = &glctx;
struct stat stbuf;
int fd, flags;
if (stat(segp->seg_path, &stbuf) < 0) {
int err = errno;
fprintf(stderr, "%s: can't stat %s - %s\n",
gcp->program_name, segp->seg_path,
strerror(err));
free_seg_slot(segp);
return SEG_ERR;
}
/*
* TODO: for now, just regular files. later?
*/
if (!S_ISREG(stbuf.st_mode)) {
fprintf(stderr, "%s: %s - is not a regular file\n",
gcp->program_name, segp->seg_path);
free_seg_slot(segp);
return SEG_ERR;
}
/*
* Open file with maximal privileges; adjust segment mapping
* protections if permissions don't allow full R/W access.
*/
if (!access(segp->seg_path, R_OK|W_OK))
flags = O_RDWR;
else if (!access(segp->seg_path, R_OK)) {
flags = O_RDONLY;
segp->seg_prot &= ~PROT_WRITE;
} else if (!access(segp->seg_path, W_OK)) {
flags = O_WRONLY;
segp->seg_prot &= ~PROT_READ;
} else {
fprintf(stderr, "%s: can't access %s\n",
gcp->program_name, segp->seg_path);
free_seg_slot(segp);
return SEG_ERR;
}
fd = open(segp->seg_path, flags);
if (fd < 0) {
int err = errno;
fprintf(stderr, "%s: can't open %s - %s\n",
gcp->program_name, segp->seg_path,
strerror(err));
free_seg_slot(segp);
return SEG_ERR;
}
segp->seg_fd = fd;
return SEG_OK;
}
/*
* called from memtoy "at exit" cleanup().
* primarily to remove any shm segments created.
*/
void segment_cleanup(struct global_context *gcp)
{
segment_t *segp, **segpp;
segpp = gcp->seglist;
if (segpp == NULL)
return;
for (; (segp = *segpp); ++segpp) {
if (segp->seg_type != SEGT_SHM) {
continue;
}
free_seg_slot(segp); /* to remove shared mem */
}
}
/*
* segment_remove() - remove the specified segment, if exists.
*/
int segment_remove(char *name)
{
glctx_t *gcp = &glctx;
segment_t *segp;
segp = segment_get(name);
if (segp == NULL) {
fprintf(stderr, "%s: no such segment: %s\n",
gcp->program_name, name);
return SEG_ERR;
}
unmap_segment(segp);
free_seg_slot(segp);
return SEG_OK;
}
/*
* get_shm_segment() -- create [shmget] a new shared memory segment
*/
static int get_shm_segment(segment_t * segp)
{
glctx_t *gcp = &glctx;
int shmid;
shmid = shmget(IPC_PRIVATE, segp->seg_length, SHM_R | SHM_W);
if (shmid == -1) {
int err = errno;
fprintf(stderr, "%s: failed to get shm segment %s - %s\n",
gcp->program_name, segp->seg_name, strerror(err));
free_seg_slot(segp);
return SEG_ERR;
}
segp->seg_shmid = shmid;
vprint("%s: shm seg %s id: %d\n",
gcp->program_name, segp->seg_name, segp->seg_shmid);
return SEG_OK;
}
