X-Git-Url: http://git.ozlabs.org/?p=petitboot;a=blobdiff_plain;f=discover%2Ffile.c;h=1bde9fb805ba906c95ca4ec24df9d1dc921994af;hp=269421cb8d02c727fb33fd607506d9c67d83710f;hb=37bff93c8b0a71432613f41f2319dc073ca64619;hpb=a70807730ef59efc4116556ecabe1b9f70ce605b

diff --git a/discover/file.c b/discover/file.c
index 269421c..1bde9fb 100644
--- a/discover/file.c
+++ b/discover/file.c
@@ -17,6 +17,8 @@
 
 #include <fcntl.h>
 #include <unistd.h>
+#include <stdlib.h>
+#include <errno.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 
@@ -75,3 +77,47 @@ err_close:
 	close(fd);
 	return -1;
 }
+
+static int write_fd(int fd, char *buf, int len)
+{
+	int i, rc;
+
+	for (i = 0; i < len; i += rc) {
+		rc = write(fd, buf + i, len - i);
+		if (rc < 0 && errno != -EINTR)
+			return rc;
+	}
+
+	return 0;
+}
+
+int replace_file(const char *filename, char *buf, int len)
+{
+	char *tempfile;
+	mode_t oldmask;
+	int rc, fd;
+
+	tempfile = talloc_asprintf(NULL, "%s.XXXXXX", filename);
+
+	oldmask = umask(0644);
+	fd = mkstemp(tempfile);
+	umask(oldmask);
+	if (fd < 0) {
+		talloc_free(tempfile);
+		return fd;
+	}
+
+	rc = write_fd(fd, buf, len);
+	if (rc) {
+		unlink(tempfile);
+	} else {
+		rc = rename(tempfile, filename);
+	}
+
+	talloc_free(tempfile);
+
+	fchmod(fd, 0644);
+
+	close(fd);
+	return rc;
+}