Add wtap_dump_open_tempfile routines, to write to a temporary file.

It includes the temporary-file generation, so you don't have to do it
yourself.

Change-Id: I0798df95a5c5646224ec49612f50b423ed78547a
Reviewed-on: https://code.wireshark.org/review/11751
Reviewed-by: Guy Harris <guy@alum.mit.edu>

2 files changed, 88 insertions, 0 deletions

diff --git a/wiretap/file_access.c b/wiretap/file_access.c
index 14c9b81b96..3ef75283bc 100644
--- a/wiretap/file_access.c
+++ b/wiretap/file_access.c
@@ -26,6 +26,7 @@
 #include <errno.h>
 
 #include <wsutil/file_util.h>
+#include <wsutil/tempfile.h>
 
 #include "wtap-int.h"
 #include "file_wrappers.h"
@@ -2240,6 +2241,62 @@ wtap_dump_open_ng(const char *filename, int file_type_subtype, int encap,
 }
 
 wtap_dumper *
+wtap_dump_open_tempfile(char **filenamep, const char *pfx,
+			int file_type_subtype, int encap,
+			int snaplen, gboolean compressed, int *err)
+{
+	return wtap_dump_open_tempfile_ng(filenamep, pfx, file_type_subtype, encap,snaplen, compressed, NULL, NULL, NULL, err);
+}
+
+wtap_dumper *
+wtap_dump_open_tempfile_ng(char **filenamep, const char *pfx,
+			   int file_type_subtype, int encap,
+			   int snaplen, gboolean compressed,
+			   wtapng_section_t *shb_hdr,
+			   wtapng_iface_descriptions_t *idb_inf,
+			   wtapng_name_res_t *nrb_hdr, int *err)
+{
+	int fd;
+	char *tmpname;
+	wtap_dumper *wdh;
+	WFILE_T fh;
+
+	/* No path name for the temporary file yet. */
+	*filenamep = NULL;
+
+	/* Allocate and initialize a data structure for the output stream. */
+	wdh = wtap_dump_init_dumper(file_type_subtype, encap, snaplen, compressed,
+	    shb_hdr, idb_inf, nrb_hdr, err);
+	if (wdh == NULL)
+		return NULL;
+
+	/* Choose a random name for the file */
+	fd = create_tempfile(&tmpname, pfx);
+	*filenamep = tmpname;
+
+	/* In case "fopen()" fails but doesn't set "errno", set "errno"
+	   to a generic "the open failed" error. */
+	errno = WTAP_ERR_CANT_OPEN;
+	fh = wtap_dump_file_fdopen(wdh, fd);
+	if (fh == NULL) {
+		*err = errno;
+		g_free(wdh);
+		return NULL;	/* can't create file */
+	}
+	wdh->fh = fh;
+
+	if (!wtap_dump_open_finish(wdh, file_type_subtype, compressed, err)) {
+		/* Get rid of the file we created; we couldn't finish
+		   opening it. */
+		wtap_dump_file_close(wdh);
+		ws_unlink(tmpname);
+		g_free(wdh);
+		return NULL;
+	}
+	return wdh;
+}
+
+wtap_dumper *
 wtap_dump_fdopen(int fd, int file_type_subtype, int encap, int snaplen,
 		 gboolean compressed, int *err)
 {
diff --git a/wiretap/wtap.h b/wiretap/wtap.h
index ccbc598c5e..e11c61adce 100644
--- a/wiretap/wtap.h
+++ b/wiretap/wtap.h
@@ -1941,6 +1941,37 @@ wtap_dumper* wtap_dump_open_ng(const char *filename, int file_type_subtype, int
     wtapng_name_res_t *nrb_hdr, int *err);
 
 WS_DLL_PUBLIC
+wtap_dumper* wtap_dump_open_tempfile(char **filenamep, const char *pfx,
+    int file_type_subtype, int encap, int snaplen, gboolean compressed,
+    int *err);
+
+/**
+ * @brief Creates a dumper for a temporary file.
+ *
+ * @note The shb_hdr, idb_inf, and nrb_hdr arguments will be used until
+ *     wtap_dump_close() is called, but will not be free'd by the dumper. If
+ *     you created them, you must free them yourself after wtap_dump_close().
+ *
+ * @param filenamep Points to a pointer that's set to point to the
+ *        pathname of the temporary file; it's allocated with g_malloc()
+ * @param pfx A string to be used as the prefix for the temporary file name
+ * @param file_type_subtype The WTAP_FILE_TYPE_SUBTYPE_XXX file type.
+ * @param encap The WTAP_ENCAP_XXX encapsulation type (WTAP_ENCAP_PER_PACKET for multi)
+ * @param snaplen The maximum packet capture length.
+ * @param compressed True if file should be compressed.
+ * @param shb_hdr The section header block information, or NULL.
+ * @param idb_inf The interface description information, or NULL.
+ * @param nrb_hdr The name resolution comment/custom_opts information, or NULL.
+ * @param[out] err Will be set to an error code on failure.
+ * @return The newly created dumper object, or NULL on failure.
+ */
+WS_DLL_PUBLIC
+wtap_dumper* wtap_dump_open_tempfile_ng(char **filenamep, const char *pfx,
+    int file_type_subtype, int encap, int snaplen, gboolean compressed,
+    wtapng_section_t *shb_hdr, wtapng_iface_descriptions_t *idb_inf,
+    wtapng_name_res_t *nrb_hdr, int *err);
+
+WS_DLL_PUBLIC
 wtap_dumper* wtap_dump_fdopen(int fd, int file_type_subtype, int encap, int snaplen,
     gboolean compressed, int *err);