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-rw-r--r--src/logic/tpax_file_create_memory_snapshot.c101
1 files changed, 101 insertions, 0 deletions
diff --git a/src/logic/tpax_file_create_memory_snapshot.c b/src/logic/tpax_file_create_memory_snapshot.c
new file mode 100644
index 0000000..7db21ea
--- /dev/null
+++ b/src/logic/tpax_file_create_memory_snapshot.c
@@ -0,0 +1,101 @@
+/******************************************************/
+/* tpax: a topological pax implementation */
+/* Copyright (C) 2020 Z. Gilboa */
+/* Released under GPLv2 and GPLv3; see COPYING.TPAX. */
+/******************************************************/
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <grp.h>
+#include <pwd.h>
+#include <sys/stat.h>
+
+#include <tpax/tpax.h>
+#include <tpax/tpax_specs.h>
+#include "tpax_driver_impl.h"
+#include "tpax_errinfo_impl.h"
+
+#ifndef ssizeof
+#define ssizeof(x) (ssize_t)(sizeof(x))
+#endif
+
+int tpax_file_create_memory_snapshot(
+ const struct tpax_driver_ctx * dctx,
+ const char * path,
+ const struct stat * srcst,
+ void * addr)
+{
+ int fd;
+ char * ch;
+ char * cap;
+ ssize_t nread;
+ struct stat dstst;
+
+ /* record errors */
+ tpax_driver_set_ectx(
+ dctx,0,path);
+
+ /* memory snapshot internal limit */
+ if (srcst->st_size >= 0x80000000)
+ return TPAX_CUSTOM_ERROR(dctx,TPAX_ERR_REGION_SIZE);
+
+ /* open */
+ fd = openat(
+ tpax_driver_fdcwd(dctx),path,
+ O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
+
+ if (fd < 0)
+ return TPAX_SYSTEM_ERROR(dctx);
+
+ /* stat compare */
+ if ((fstat(fd,&dstst)) < 0) {
+ close(fd);
+ return TPAX_SYSTEM_ERROR(dctx);
+
+ } else if (tpax_stat_compare(srcst,&dstst)) {
+ close(fd);
+ return TPAX_CUSTOM_ERROR(dctx,TPAX_ERR_FILE_CHANGED);
+ }
+
+ /* read loop */
+ ch = addr;
+ cap = &ch[srcst->st_size];
+
+ while (ch < cap) {
+ nread = read(fd,ch,cap-ch);
+
+ while ((nread < 0) && (errno == EINTR))
+ nread = read(fd,ch,cap-ch);
+
+ if (nread < 0) {
+ close(fd);
+ return TPAX_SYSTEM_ERROR(dctx);
+
+ } else if (nread == 0) {
+ close(fd);
+ return TPAX_CUSTOM_ERROR(dctx,TPAX_ERR_FLOW_ERROR);
+
+ } else {
+ ch += nread;
+ }
+ }
+
+ /* stat compare */
+ if ((fstat(fd,&dstst)) < 0) {
+ close(fd);
+ return TPAX_SYSTEM_ERROR(dctx);
+
+ } else if (tpax_stat_compare(srcst,&dstst)) {
+ close(fd);
+ return TPAX_CUSTOM_ERROR(dctx,TPAX_ERR_FILE_CHANGED);
+ }
+
+ /* yay */
+ close(fd);
+
+ return 0;
+}