From c365aeb0721d3749bb5f94f09a3ad97ec6131805 Mon Sep 17 00:00:00 2001
From: Laurent Bercot <ska-skaware@skarnet.org>
Date: Wed, 27 Sep 2017 20:16:01 +0000
Subject:  Rewrite openwrite(v)nclose using mkstemp

---
 src/libstddjb/openwritenclose.c         | 38 ++++++++++++++++++++++++++++++++
 src/libstddjb/openwritenclose_unsafe.c  | 17 ++++----------
 src/libstddjb/openwritevnclose.c        | 39 +++++++++++++++++++++++++++++++++
 src/libstddjb/openwritevnclose_unsafe.c | 17 ++++----------
 src/libstddjb/writenclose_unsafe.c      | 18 +++++++++++++++
 src/libstddjb/writevnclose_unsafe.c     | 20 +++++++++++++++++
 6 files changed, 123 insertions(+), 26 deletions(-)
 create mode 100644 src/libstddjb/openwritenclose.c
 create mode 100644 src/libstddjb/openwritevnclose.c
 create mode 100644 src/libstddjb/writenclose_unsafe.c
 create mode 100644 src/libstddjb/writevnclose_unsafe.c

(limited to 'src/libstddjb')

diff --git a/src/libstddjb/openwritenclose.c b/src/libstddjb/openwritenclose.c
new file mode 100644
index 0000000..427e53e
--- /dev/null
+++ b/src/libstddjb/openwritenclose.c
@@ -0,0 +1,38 @@
+/* ISC license. */
+
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <skalibs/djbunix.h>
+
+#define SUFFIX ":skalibs-openwritenclose:XXXXXX"
+
+int openwritenclose_internal (char const *fn, char const *s, size_t n, dev_t *dev, ino_t *ino, int dosync)
+{
+  dev_t tmpdev ;
+  ino_t tmpino ;
+  size_t fnlen = strlen(fn) ;
+  int fd ;
+  char tmp[fnlen + sizeof(SUFFIX)] ;
+  memcpy(tmp, fn, fnlen) ;
+  memcpy(tmp + fnlen, SUFFIX, sizeof(SUFFIX)) ;
+  fd = mkstemp(tmp) ;
+  if (fd < 0) return 0 ;
+  if (!writenclose_unsafe_internal(fd, s, n, dev ? &tmpdev : 0, ino ? &tmpino : 0, dosync)) goto failclose ;
+  if (rename(tmp, fn) < 0) goto fail ;
+  if (dev) *dev = tmpdev ;
+  if (ino) *ino = tmpino ;
+  return 1 ;
+
+ failclose:
+  fd_close(fd) ;
+ fail:
+  {
+    int e = errno ;
+    unlink(tmp) ;
+    errno = e ;
+  }
+  return 0 ;
+}
diff --git a/src/libstddjb/openwritenclose_unsafe.c b/src/libstddjb/openwritenclose_unsafe.c
index 3aebd97..e5ac260 100644
--- a/src/libstddjb/openwritenclose_unsafe.c
+++ b/src/libstddjb/openwritenclose_unsafe.c
@@ -1,30 +1,21 @@
 /* ISC license. */
 
-#include <sys/stat.h>
 #include <errno.h>
 #include <unistd.h>
-#include <skalibs/allreadwrite.h>
 #include <skalibs/djbunix.h>
 
 int openwritenclose_unsafe_internal (char const *fn, char const *s, size_t len, dev_t *dev, ino_t *ino, int dosync)
 {
-  struct stat st ;
   int fd = open_trunc(fn) ;
   if (fd < 0) return 0 ;
-  if (allwrite(fd, s, len) < len) goto fail ;
-  if ((dev || ino) && (fstat(fd, &st) < 0)) goto fail ;
-  if (dosync && (fd_sync(fd) < 0) && (errno != EINVAL)) goto fail ;
-  fd_close(fd) ;
-  if (dev) *dev = st.st_dev ;
-  if (ino) *ino = st.st_ino ;
-  return 1 ;
-
- fail:
+  if (!writenclose_unsafe_internal(fd, s, len, dev, ino, dosync))
   {
     int e = errno ;
     fd_close(fd) ;
     unlink(fn) ;
     errno = e ;
+    return 0 ;
   }
-  return 0 ;
+  fd_close(fd) ;
+  return 1 ;
 }
diff --git a/src/libstddjb/openwritevnclose.c b/src/libstddjb/openwritevnclose.c
new file mode 100644
index 0000000..01df3e3
--- /dev/null
+++ b/src/libstddjb/openwritevnclose.c
@@ -0,0 +1,39 @@
+/* ISC license. */
+
+#include <sys/uio.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <skalibs/djbunix.h>
+
+#define SUFFIX ":skalibs-openwritevnclose:XXXXXX"
+
+int openwritevnclose_internal (char const *fn, struct iovec const *v, unsigned int vlen, dev_t *dev, ino_t *ino, int dosync)
+{
+  dev_t tmpdev ;
+  ino_t tmpino ;
+  size_t fnlen = strlen(fn) ;
+  int fd ;
+  char tmp[fnlen + sizeof(SUFFIX)] ;
+  memcpy(tmp, fn, fnlen) ;
+  memcpy(tmp + fnlen, SUFFIX, sizeof(SUFFIX)) ;
+  fd = mkstemp(tmp) ;
+  if (fd < 0) return 0 ;
+  if (!writevnclose_unsafe_internal(fd, v, vlen, dev ? &tmpdev : 0, ino ? &tmpino : 0, dosync)) goto failclose ;
+  if (rename(tmp, fn) < 0) goto fail ;
+  if (dev) *dev = tmpdev ;
+  if (ino) *ino = tmpino ;
+  return 1 ;
+
+ failclose:
+  fd_close(fd) ;
+ fail:
+  {
+    int e = errno ;
+    unlink(tmp) ;
+    errno = e ;
+  }
+  return 0 ;
+}
diff --git a/src/libstddjb/openwritevnclose_unsafe.c b/src/libstddjb/openwritevnclose_unsafe.c
index 4bc7b2b..ddcbfd3 100644
--- a/src/libstddjb/openwritevnclose_unsafe.c
+++ b/src/libstddjb/openwritevnclose_unsafe.c
@@ -1,32 +1,23 @@
 /* ISC license. */
 
 #include <sys/uio.h>
-#include <sys/stat.h>
 #include <errno.h>
 #include <unistd.h>
 #include <skalibs/allreadwrite.h>
-#include <skalibs/siovec.h>
 #include <skalibs/djbunix.h>
 
 int openwritevnclose_unsafe_internal (char const *fn, struct iovec const *v, unsigned int vlen, dev_t *dev, ino_t *ino, int dosync)
 {
-  struct stat st ;
   int fd = open_trunc(fn) ;
   if (fd < 0) return 0 ;
-  if (allwritev(fd, v, vlen) < siovec_len(v, vlen)) goto fail ;
-  if ((dev || ino) && (fstat(fd, &st) < 0)) goto fail ;
-  if (dosync && (fd_sync(fd) < 0) && (errno != EINVAL)) goto fail ;
-  fd_close(fd) ;
-  if (dev) *dev = st.st_dev ;
-  if (ino) *ino = st.st_ino ;
-  return 1 ;
-
- fail:
+  if (!writevnclose_unsafe_internal(fd, v, vlen, dev, ino, dosync))
   {
     int e = errno ;
     fd_close(fd) ;
     unlink(fn) ;
     errno = e ;
+    return 0 ;
   }
-  return 0 ;
+  fd_close(fd) ;
+  return 1 ;
 }
diff --git a/src/libstddjb/writenclose_unsafe.c b/src/libstddjb/writenclose_unsafe.c
new file mode 100644
index 0000000..f71caea
--- /dev/null
+++ b/src/libstddjb/writenclose_unsafe.c
@@ -0,0 +1,18 @@
+/* ISC license. */
+
+#include <sys/stat.h>
+#include <errno.h>
+#include <skalibs/allreadwrite.h>
+#include <skalibs/djbunix.h>
+
+int writenclose_unsafe_internal (int fd, char const *s, size_t len, dev_t *dev, ino_t *ino, int dosync)
+{
+  struct stat st ;
+  if (allwrite(fd, s, len) < len) return 0 ;
+  if ((dev || ino) && (fstat(fd, &st) < 0)) return 0 ;
+  if (dosync && (fd_sync(fd) < 0) && (errno != EINVAL)) return 0 ;
+  fd_close(fd) ;
+  if (dev) *dev = st.st_dev ;
+  if (ino) *ino = st.st_ino ;
+  return 1 ;
+}
diff --git a/src/libstddjb/writevnclose_unsafe.c b/src/libstddjb/writevnclose_unsafe.c
new file mode 100644
index 0000000..9d2348a
--- /dev/null
+++ b/src/libstddjb/writevnclose_unsafe.c
@@ -0,0 +1,20 @@
+/* ISC license. */
+
+#include <sys/uio.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <skalibs/allreadwrite.h>
+#include <skalibs/siovec.h>
+#include <skalibs/djbunix.h>
+
+int writevnclose_unsafe_internal (int fd, struct iovec const *v, unsigned int vlen, dev_t *dev, ino_t *ino, int dosync)
+{
+  struct stat st ;
+  if (allwritev(fd, v, vlen) < siovec_len(v, vlen)) return 0 ;
+  if ((dev || ino) && (fstat(fd, &st) < 0)) return 0 ;
+  if (dosync && (fd_sync(fd) < 0) && (errno != EINVAL)) return 0 ;
+  fd_close(fd) ;
+  if (dev) *dev = st.st_dev ;
+  if (ino) *ino = st.st_ino ;
+  return 1 ;
+}
-- 
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