Merge pull request cathugger#61 from scribblemaniac/checkpointing

Add checkpointing support for passphrases

ioutil.c

@@ -1,7 +1,10 @@
 #include <stdint.h>
 #include <string.h>
+#include <stdlib.h>
 #include "types.h"
 #include "ioutil.h"
+#include "vec.h"
+#include <stdio.h>
 
 #ifndef _WIN32
 
@@ -31,7 +34,7 @@ FH createfile(const char *path,int secret)
  int fd;
  do {
  fd = open(path,O_WRONLY | O_CREAT | O_TRUNC,secret ? 0600 : 0666);
- if (fd == -1) {
+ if (fd < 0) {
  if (errno == EINTR)
  continue;
  return -1;
@@ -45,7 +48,7 @@ int closefile(FH fd)
  int cret;
  do {
  cret = close(fd);
- if (cret == -1) {
+ if (cret < 0) {
  if (errno == EINTR)
  continue;
  return -1;
@@ -59,6 +62,122 @@ int createdir(const char *path,int secret)
  return mkdir(path,secret ? 0700 : 0777);
 }
 
+static int syncwritefile(const char *filename,const char *tmpname,int secret,const u8 *data,size_t datalen)
+{
+ FH f = createfile(tmpname,secret);
+ if (f == FH_invalid)
+ return -1;
+
+ if (writeall(f,data,datalen) < 0) {
+ goto failclose;
+ }
+
+ int sret;
+ do {
+ sret = fsync(f);
+ if (sret < 0) {
+ if (errno == EINTR)
+ continue;
+
+ goto failclose;
+ }
+ } while (0);
+
+ if (closefile(f) < 0) {
+ goto failrm;
+ }
+
+ if (rename(tmpname,filename) < 0) {
+ goto failrm;
+ }
+
+ return 0;
+
+failclose:
+ (void) closefile(f);
+failrm:
+ remove(tmpname);
+
+ return -1;
+}
+
+int syncwrite(const char *filename,int secret,const u8 *data,size_t datalen)
+{
+ //fprintf(stderr,"filename = %s\n",filename);
+
+ size_t fnlen = strlen(filename);
+
+ VEC_STRUCT(,char) tmpnamebuf;
+ VEC_INIT(tmpnamebuf);
+ VEC_ADDN(tmpnamebuf,fnlen + 4 /* ".tmp" */ + 1 /* "\0" */);
+ memcpy(&VEC_BUF(tmpnamebuf,0),filename,fnlen);
+ strcpy(&VEC_BUF(tmpnamebuf,fnlen),".tmp");
+ const char *tmpname = &VEC_BUF(tmpnamebuf,0);
+
+ //fprintf(stderr,"tmpname = %s\n",tmpname);
+
+ int r = syncwritefile(filename,tmpname,secret,data,datalen);
+
+ VEC_FREE(tmpnamebuf);
+
+ if (r < 0)
+ return r;
+
+ VEC_STRUCT(,char) dirnamebuf;
+ VEC_INIT(dirnamebuf);
+ const char *dirname;
+
+ for (ssize_t x = ((ssize_t)fnlen) - 1;x >= 0;--x) {
+ if (filename[x] == '/') {
+ if (x)
+ --x;
+ ++x;
+ VEC_ADDN(dirnamebuf,x + 1);
+ memcpy(&VEC_BUF(dirnamebuf,0),filename,x);
+ VEC_BUF(dirnamebuf,x) = '\0';
+ dirname = &VEC_BUF(dirnamebuf,0);
+ goto foundslash;
+ }
+ }
+ /* not found slash, fall back to "." */
+ dirname = ".";
+
+foundslash:
+ //fprintf(stderr,"dirname = %s\n",dirname);
+ ;
+
+ int dirf;
+ do {
+ dirf = open(dirname,O_RDONLY);
+ if (dirf < 0) {
+ if (errno == EINTR)
+ continue;
+
+ // failed for non-eintr reasons
+ goto skipdsync; // don't really care enough
+ }
+ } while (0);
+
+ int sret;
+ do {
+ sret = fsync(dirf);
+ if (sret < 0) {
+ if (errno == EINTR)
+ continue;
+
+ // failed for non-eintr reasons
+ break; // don't care
+ }
+ } while (0);
+
+ (void) closefile(dirf); // don't care
+
+skipdsync:
+ VEC_FREE(dirnamebuf);
+
+ return 0;
+}
+
 #else
 
 int writeall(FH fd,const u8 *data,size_t len)
@@ -99,6 +218,61 @@ int createdir(const char *path,int secret)
  return CreateDirectoryA(path,0) ? 0 : -1;
 }
 
+static int syncwritefile(const char *filename,const char *tmpname,int secret,const char *data,size_t datalen)
+{
+ FH f = createfile(tmpnamestr,secret)
+ if (f == FH_invalid)
+ return -1;
+
+ if (writeall(f,data,datalen) < 0) {
+ goto failclose;
+ }
+
+ if (FlushFileBuffers(f) == 0) {
+ goto failclose;
+ }
+
+ if (closefile(f) < 0) {
+ goto failrm;
+ }
+
+ if (MoveFileA(tmpnamestr,filename) == 0) {
+ goto failrm;
+ }
+
+ return 0;
+
+failclose:
+ (void) closefile(f);
+failrm:
+ remove(tmpnamestr);
+
+ return -1;
+}
+
+int syncwrite(const char *filename,int secret,const char *data,size_t datalen)
+{
+ size_t fnlen = strlen(filename);
+
+ VEC_STRUCT(,char) tmpnamebuf;
+ VEC_INIT(tmpnamebuf);
+ VEC_ADDN(tmpnamebuf,fnlen + 4 /* ".tmp" */ + 1 /* "\0" */);
+ memcpy(&VEC_BUF(tmpnamebuf,0),filename,fnlen);
+ strcpy(&VEC_BUF(tmpnamebuf,fnlen),".tmp");
+ const char *tmpname = &VEC_BUF(tmpnamebuf,0);
+
+ int r = syncwritefile(filename,tmpname,secret,data,datalen);
+
+ VEC_FREE(tmpnamebuf);
+
+ if (r < 0)
+ return r;
+
+ // can't fsync parent dir on windows so just end here
+
+ return 0;
+}
+
 #endif
 
 int writetofile(const char *path,const u8 *data,size_t len,int secret)

ioutil.h

@@ -18,3 +18,4 @@ int closefile(FH fd);
 int writeall(FH,const u8 *data,size_t len);
 int writetofile(const char *path,const u8 *data,size_t len,int secret);
 int createdir(const char *path,int secret);
+int syncwrite(const char *filename,int secret,const u8 *data,size_t datalen);