chunk: Externalize error reporting in chunk_write()

This avoids passing that arbitrary label just for error messages, and gives
greater flexibility in handling errors.

src/libcharon/plugins/stroke/stroke_cred.c

@@ -521,7 +521,16 @@ METHOD(stroke_cred_t, cache_cert, void,
 
 			if (cert->get_encoding(cert, CERT_ASN1_DER, &chunk))
 			{
-				chunk_write(chunk, buf, "crl", 022, TRUE);
+				if (chunk_write(chunk, buf, 022, TRUE))
+				{
+					DBG1(DBG_CFG, "  written crl file '%s' (%d bytes)",
+						 buf, chunk.len);
+				}
+				else
+				{
+					DBG1(DBG_CFG, "  writing crl file '%s' failed: %s",
+						 buf, strerror(errno));
+				}
 				free(chunk.ptr);
 			}
 		}

src/libstrongswan/tests/suites/test_chunk.c

@@ -789,7 +789,7 @@ START_TEST(test_chunk_map)
 	chunk_t *map, contents = chunk_from_chars(0x01,0x02,0x03,0x04,0x05);
 	char *path = "/tmp/strongswan-chunk-map-test";
 
-	ck_assert(chunk_write(contents, path, "chunk_map", 022, TRUE));
+	ck_assert(chunk_write(contents, path, 022, TRUE));
 
 	/* read */
 	map = chunk_map(path, FALSE);
@@ -827,7 +827,7 @@ START_TEST(test_chunk_from_fd_file)
 	char *path = "/tmp/strongswan-chunk-fd-test";
 	int fd;
 
-	ck_assert(chunk_write(contents, path, "chunk_fd", 022, TRUE));
+	ck_assert(chunk_write(contents, path, 022, TRUE));
 
 	fd = open(path, O_RDONLY);
 	ck_assert(fd != -1);

src/libstrongswan/utils/chunk.c

@@ -28,7 +28,6 @@
 #include <ctype.h>
 
 #include "chunk.h"
-#include "debug.h"
 
 /**
  * Empty chunk.
@@ -209,15 +208,16 @@ void chunk_split(chunk_t chunk, const char *mode, ...)
 /**
  * Described in header.
  */
-bool chunk_write(chunk_t chunk, char *path, char *label, mode_t mask, bool force)
+bool chunk_write(chunk_t chunk, char *path, mode_t mask, bool force)
 {
 	mode_t oldmask;
 	FILE *fd;
 	bool good = FALSE;
+	int tmp = 0;
 
 	if (!force && access(path, F_OK) == 0)
 	{
-		DBG1(DBG_LIB, "  %s file '%s' already exists", label, path);
+		errno = EEXIST;
 		return FALSE;
 	}
 	oldmask = umask(mask);
@@ -226,23 +226,20 @@ bool chunk_write(chunk_t chunk, char *path, char *label, mode_t mask, bool force
 	{
 		if (fwrite(chunk.ptr, sizeof(u_char), chunk.len, fd) == chunk.len)
 		{
-			DBG1(DBG_LIB, "  written %s file '%s' (%d bytes)",
-				 label, path, chunk.len);
 			good = TRUE;
 		}
 		else
 		{
-			DBG1(DBG_LIB, "  writing %s file '%s' failed: %s",
+			tmp = errno;
-				 label, path, strerror(errno));
 		}
 		fclose(fd);
 	}
 	else
 	{
-		DBG1(DBG_LIB, "  could not open %s file '%s': %s", label, path,
+		tmp = errno;
-			 strerror(errno));
 	}
 	umask(oldmask);
+	errno = tmp;
 	return good;
 }
 

src/libstrongswan/utils/chunk.h

@@ -90,14 +90,15 @@ void chunk_split(chunk_t chunk, const char *mode, ...);
 /**
  * Write the binary contents of a chunk_t to a file
  *
+ * If the write fails, errno is set appropriately.
+ *
  * @param chunk			contents to write to file
  * @param path			path where file is written to
- * @param label			label specifying file type
  * @param mask			file mode creation mask
  * @param force			overwrite existing file by force
  * @return				TRUE if write operation was successful
  */
-bool chunk_write(chunk_t chunk, char *path, char *label, mode_t mask, bool force);
+bool chunk_write(chunk_t chunk, char *path, mode_t mask, bool force);
 
 /**
  * Store data read from FD into a chunk

src/openac/openac.c

@@ -29,6 +29,7 @@
 #include <getopt.h>
 #include <ctype.h>
 #include <time.h>
+#include <errno.h>
 
 #include <library.h>
 #include <utils/debug.h>
@@ -515,11 +516,18 @@ int main(int argc, char **argv)
 		/* write the attribute certificate to file */
 		if (attr_cert->get_encoding(attr_cert, CERT_ASN1_DER, &attr_chunk))
 		{
-			if (chunk_write(attr_chunk, outfile, "attribute cert", 0022, TRUE))
+			if (chunk_write(attr_chunk, outfile, 0022, TRUE))
 			{
+				DBG1(DBG_APP, "  written attribute cert file '%s' (%d bytes)",
+						 outfile, attr_chunk.len);
 				write_serial(serial);
 				status = 0;
 			}
+			else
+			{
+				DBG1(DBG_APP, "  writing attribute cert file '%s' failed: %s",
+					 outfile, strerror(errno));
+			}
 		}
 	}
 	else

src/scepclient/scepclient.c

@@ -24,6 +24,7 @@
 #include <time.h>
 #include <limits.h>
 #include <syslog.h>
+#include <errno.h>
 
 #include <library.h>
 #include <utils/debug.h>
@@ -975,9 +976,10 @@ int main(int argc, char **argv)
 		{	/* no PKCS#7 encoded CA+RA certificates, assume simple CA cert */
 
 			DBG1(DBG_APP, "unable to parse PKCS#7, assuming plain CA cert");
-			if (!chunk_write(scep_response, ca_path, "ca cert",  0022, force))
+			if (!chunk_write(scep_response, ca_path, 0022, force))
 			{
-				exit_scepclient("could not write ca cert file '%s'", ca_path);
+				exit_scepclient("could not write ca cert file '%s': %s",
+								ca_path, strerror(errno));
 			}
 		}
 		else
@@ -1031,10 +1033,10 @@ int main(int argc, char **argv)
 				}
 
 				if (!cert->get_encoding(cert, CERT_ASN1_DER, &encoding) ||
-					!chunk_write(encoding, path,
+					!chunk_write(encoding, path, 0022, force))
-								 ca_cert ? "ca cert" : "ra cert", 0022, force))
 				{
-					exit_scepclient("could not write cert file '%s'", path);
+					exit_scepclient("could not write cert file '%s': %s",
+									path, strerror(errno));
 				}
 				chunk_free(&encoding);
 			}
@@ -1149,9 +1151,10 @@ int main(int argc, char **argv)
 
 		join_paths(path, sizeof(path), REQ_PATH, file_out_pkcs10);
 
-		if (!chunk_write(pkcs10_encoding, path, "pkcs10",  0022, force))
+		if (!chunk_write(pkcs10_encoding, path, 0022, force))
 		{
-			exit_scepclient("could not write pkcs10 file '%s'", path);
+			exit_scepclient("could not write pkcs10 file '%s': %s",
+							path, strerror(errno));
 		}
 		filetype_out &= ~PKCS10;   /* delete PKCS10 flag */
 	}
@@ -1172,9 +1175,10 @@ int main(int argc, char **argv)
 
 		DBG2(DBG_APP, "building pkcs1 object:");
 		if (!private_key->get_encoding(private_key, PRIVKEY_ASN1_DER, &pkcs1) ||
-			!chunk_write(pkcs1, path, "pkcs1", 0066, force))
+			!chunk_write(pkcs1, path, 0066, force))
 		{
-			exit_scepclient("could not write pkcs1 file '%s'", path);
+			exit_scepclient("could not write pkcs1 file '%s': %s",
+							path, strerror(errno));
 		}
 		filetype_out &= ~PKCS1;   /* delete PKCS1 flag */
 	}
@@ -1236,9 +1240,10 @@ int main(int argc, char **argv)
 		{
 			exit_scepclient("encoding certificate failed");
 		}
-		if (!chunk_write(encoding, path, "self-signed cert", 0022, force))
+		if (!chunk_write(encoding, path, 0022, force))
 		{
-			exit_scepclient("could not write self-signed cert file '%s'", path);
+			exit_scepclient("could not write self-signed cert file '%s': %s",
+							path, strerror(errno));
 		}
 		chunk_free(&encoding);
 		filetype_out &= ~CERT_SELF;   /* delete CERT_SELF flag */
@@ -1300,9 +1305,10 @@ int main(int argc, char **argv)
 
 		join_paths(path, sizeof(path), REQ_PATH, file_out_pkcs7);
 
-		if (!chunk_write(pkcs7, path, "pkcs7 encrypted request", 0022, force))
+		if (!chunk_write(pkcs7, path, 0022, force))
 		{
-			exit_scepclient("could not write pkcs7 file '%s'", path);
+			exit_scepclient("could not write pkcs7 file '%s': %s",
+							path, strerror(errno));
 		}
 		filetype_out &= ~PKCS7;   /* delete PKCS7 flag */
 	}
@@ -1460,9 +1466,10 @@ int main(int argc, char **argv)
 					exit_scepclient("multiple certs received, only first stored");
 				}
 				if (!cert->get_encoding(cert, CERT_ASN1_DER, &encoding) ||
-					!chunk_write(encoding, path, "requested cert", 0022, force))
+					!chunk_write(encoding, path, 0022, force))
 				{
-					exit_scepclient("could not write cert file '%s'", path);
+					exit_scepclient("could not write cert file '%s': %s",
+									path, strerror(errno));
 				}
 				chunk_free(&encoding);
 				stored = TRUE;