--- /dev/null
+/* Licensed under Apache License v2.0 - see LICENSE file for details */
+#include "config.h"
+#include "rszshm.h"
+
+#define _XOPEN_SOURCE 700
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/file.h>
+
+#define pgup(x, pgsz) (((x) + (pgsz) - 1) & ~((pgsz) - 1))
+
+void *rszshm_mk(struct rszshm *r, size_t flen, const char *fname, struct rszshm_scan scan)
+{
+ long pgsz = sysconf(_SC_PAGE_SIZE);
+ int i, errno_;
+ char *m, *tgt, *p = NULL;
+
+ if (!r || flen == 0 || scan.len < flen + sizeof(*r->hdr) ||
+ !scan.start || scan.len == 0 || scan.hop == 0 || scan.iter == 0 ||
+ (fname && strnlen(fname, RSZSHM_PATH_MAX) == RSZSHM_PATH_MAX)) {
+ errno = EINVAL;
+ return NULL;
+ }
+
+ *r = (typeof(*r)) { -1, 0, "", NULL, NULL };
+ strcpy(r->fname, fname ? fname : RSZSHM_DFLT_FNAME);
+
+ flen = pgup(flen + sizeof(*r->hdr), pgsz);
+ scan.len = pgup(scan.len, pgsz);
+
+ for (i = 1, tgt = scan.start; i <= scan.iter; i++) {
+ m = mmap(tgt, scan.len, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON|MAP_NORESERVE, -1, 0);
+ if (m == MAP_FAILED)
+ return NULL;
+ if (m == tgt)
+ break;
+ munmap(m, scan.len);
+ m = NULL;
+ tgt += (i % 2 == 0 ? 1 : -1) * i * scan.hop;
+ }
+ if (!m) {
+ errno = ENOSPC;
+ return NULL;
+ }
+
+ if ((p = strstr(r->fname, "XXXXXX/")) != NULL) {
+ p += 6;
+ *p = '\0';
+ if (!mkdtemp(r->fname))
+ goto err;
+ *p = '/';
+ }
+
+ if ((r->fd = open(r->fname, O_CREAT|O_EXCL|O_RDWR, p ? 0600 : 0666)) == -1)
+ goto err;
+
+ if (ftruncate(r->fd, flen) == -1)
+ goto err;
+
+ if (mmap(m, flen, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, r->fd, 0) == MAP_FAILED)
+ goto err;
+
+ *(r->hdr = (typeof(r->hdr)) m) = (typeof(*r->hdr)) { flen, scan.len, m };
+
+ if (msync(m, sizeof(*r->hdr), MS_SYNC) == -1)
+ goto err;
+
+ r->flen = flen;
+ r->cap = flen - sizeof(*r->hdr);
+ r->dat = m + sizeof(*r->hdr);
+
+ return r->dat;
+
+err:
+ errno_ = errno;
+ if (m && m != MAP_FAILED)
+ munmap(m, scan.len);
+ if (r->fd != -1) {
+ close(r->fd);
+ unlink(r->fname);
+ }
+ if (p) {
+ *p = '\0';
+ rmdir(r->fname);
+ *p = '/';
+ }
+ errno = errno_;
+ return NULL;
+}
+
+void *rszshm_at(struct rszshm *r, const char *fname)
+{
+ struct rszshm_hdr h;
+ int fd = -1, ret, errno_;
+ char *m = NULL;
+
+ if (!r || !fname || !fname[0] ||
+ strnlen(fname, RSZSHM_PATH_MAX) == RSZSHM_PATH_MAX) {
+ errno = EINVAL;
+ return NULL;
+ }
+
+ if ((fd = open(fname, O_RDWR)) == -1)
+ return NULL;
+
+ if ((ret = read(fd, &h, sizeof(h))) == -1)
+ goto err;
+
+ if (ret != sizeof(h) || !h.addr || h.flen == 0 || h.max == 0) {
+ errno = ENODATA;
+ goto err;
+ }
+
+ m = mmap(h.addr, h.max, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON|MAP_NORESERVE, -1, 0);
+ if (m == MAP_FAILED)
+ goto err;
+ if (m != h.addr) {
+ errno = ENOSPC;
+ goto err;
+ }
+
+ if (mmap(m, h.flen, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, 0) == MAP_FAILED)
+ goto err;
+
+ *r = (typeof(*r)) { .fd = fd, .flen = h.flen, .hdr = (typeof(r->hdr)) m,
+ .dat = m + sizeof(h), .cap = h.flen - sizeof(h) };
+ strcpy(r->fname, fname);
+
+ return r->dat;
+
+err:
+ errno_ = errno;
+ if (m && m != MAP_FAILED)
+ munmap(m, h.max);
+ close(fd);
+ errno = errno_;
+ return NULL;
+}
+
+#undef rszshm_up
+int rszshm_up(struct rszshm *r)
+{
+ size_t flen;
+
+ assert(r);
+
+ flen = r->hdr->flen;
+ if (r->flen == flen)
+ return 0;
+ if (mmap(r->hdr, flen, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, r->fd, 0) == MAP_FAILED)
+ return -1;
+
+ r->flen = flen;
+ r->cap = flen - sizeof(*r->hdr);
+ return 1;
+}
+
+int rszshm_grow(struct rszshm *r)
+{
+ int ret;
+ assert(r);
+
+ if ((ret = rszshm_up(r)) != 0)
+ return ret;
+
+ if (r->flen == r->hdr->max) {
+ errno = ENOMEM;
+ return -1;
+ }
+
+ if (flock(r->fd, LOCK_EX) == -1)
+ return -1;
+
+ if ((ret = rszshm_up(r)) == 0) {
+ int flen = r->hdr->flen * 2 < r->hdr->max ? r->hdr->flen * 2 : r->hdr->max;
+
+ if (ftruncate(r->fd, flen) != -1 &&
+ mmap(r->hdr, flen, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, r->fd, 0) != MAP_FAILED) {
+ r->flen = r->hdr->flen = flen;
+ r->cap = flen - sizeof(*r->hdr);
+ ret = 1;
+ }
+ else
+ ret = -1;
+ }
+
+ flock(r->fd, LOCK_UN);
+ return ret;
+}
+
+int rszshm_dt(struct rszshm *r)
+{
+ int ret[3];
+ assert(r);
+
+ /* ok to call twice, since free macro calls this */
+ if (r->fd == -1)
+ return 0;
+
+ ret[0] = msync(r->hdr, r->flen, MS_SYNC);
+ ret[1] = munmap(r->hdr, r->hdr->max);
+ ret[2] = close(r->fd);
+
+ r->fd = -1;
+ r->flen = 0;
+ r->hdr = NULL;
+ r->dat = NULL;
+ r->cap = 0;
+
+ return ret[0] == 0 && ret[1] == 0 && ret[2] == 0 ? 0 : -1;
+}
+
+int rszshm_unlink(struct rszshm *r)
+{
+ assert(r);
+ return unlink(r->fname);
+}
+
+int rszshm_rmdir(struct rszshm *r)
+{
+ int ret;
+ char *p;
+
+ assert(r);
+
+ if ((p = strrchr(r->fname, '/')) == NULL) {
+ errno = ENOTDIR;
+ return -1;
+ }
+
+ *p = '\0';
+ ret = rmdir(r->fname);
+ *p = '/';
+ return ret;
+}
projects / ccan / blobdiff