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/**************************************************************/
/* tpax: a topological pax implementation */
/* Copyright (C) 2020--2021 SysDeer Technologies, LLC */
/* 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,
int fdat,
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 */
if ((fd = openat(fdat,path,O_CLOEXEC|O_NOCTTY|O_NOFOLLOW,0)) < 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;
}
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