1 files changed, 112 insertions, 0 deletions
diff --git a/archival/libunarchive/get_header_ar.c b/archival/libunarchive/get_header_ar.c
new file mode 100644
index 0000000..7f8c81c
--- /dev/null
+++ b/archival/libunarchive/get_header_ar.c
@@ -0,0 +1,112 @@
+/* vi: set sw=4 ts=4: */
+/* Copyright 2001 Glenn McGrath.
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ */
+
+#include "libbb.h"
+#include "unarchive.h"
+
+char get_header_ar(archive_handle_t *archive_handle)
+{
+	file_header_t *typed = archive_handle->file_header;
+	union {
+		char raw[60];
+		struct {
+			char name[16];
+			char date[12];
+			char uid[6];
+			char gid[6];
+			char mode[8];
+			char size[10];
+			char magic[2];
+		} formatted;
+	} ar;
+#ifdef CONFIG_FEATURE_AR_LONG_FILENAMES
+	static char *ar_long_names;
+	static unsigned int ar_long_name_size;
+#endif
+
+	/* dont use xread as we want to handle the error ourself */
+	if (read(archive_handle->src_fd, ar.raw, 60) != 60) {
+		/* End Of File */
+		return EXIT_FAILURE;
+	}
+
+	/* ar header starts on an even byte (2 byte aligned)
+	 * '\n' is used for padding
+	 */
+	if (ar.raw[0] == '\n') {
+		/* fix up the header, we started reading 1 byte too early */
+		memmove(ar.raw, &ar.raw[1], 59);
+		ar.raw[59] = xread_char(archive_handle->src_fd);
+		archive_handle->offset++;
+	}
+	archive_handle->offset += 60;
+
+	/* align the headers based on the header magic */
+	if ((ar.formatted.magic[0] != '`') || (ar.formatted.magic[1] != '\n')) {
+		bb_error_msg_and_die("invalid ar header");
+	}
+
+	typed->mode = xstrtoul(ar.formatted.mode, 8);
+	typed->mtime = xatou(ar.formatted.date);
+	typed->uid = xatou(ar.formatted.uid);
+	typed->gid = xatou(ar.formatted.gid);
+	typed->size = xatoul(ar.formatted.size);
+
+	/* long filenames have '/' as the first character */
+	if (ar.formatted.name[0] == '/') {
+#ifdef CONFIG_FEATURE_AR_LONG_FILENAMES
+		if (ar.formatted.name[1] == '/') {
+			/* If the second char is a '/' then this entries data section
+			 * stores long filename for multiple entries, they are stored
+			 * in static variable long_names for use in future entries */
+			ar_long_name_size = typed->size;
+			ar_long_names = xmalloc(ar_long_name_size);
+			xread(archive_handle->src_fd, ar_long_names, ar_long_name_size);
+			archive_handle->offset += ar_long_name_size;
+			/* This ar entries data section only contained filenames for other records
+			 * they are stored in the static ar_long_names for future reference */
+			return get_header_ar(archive_handle); /* Return next header */
+		} else if (ar.formatted.name[1] == ' ') {
+			/* This is the index of symbols in the file for compilers */
+			data_skip(archive_handle);
+			archive_handle->offset += typed->size;
+			return get_header_ar(archive_handle); /* Return next header */
+		} else {
+			/* The number after the '/' indicates the offset in the ar data section
+			(saved in variable long_name) that conatains the real filename */
+			const unsigned int long_offset = atoi(&ar.formatted.name[1]);
+			if (long_offset >= ar_long_name_size) {
+				bb_error_msg_and_die("can't resolve long filename");
+			}
+			typed->name = xstrdup(ar_long_names + long_offset);
+		}
+#else
+		bb_error_msg_and_die("long filenames not supported");
+#endif
+	} else {
+		/* short filenames */
+		typed->name = xstrndup(ar.formatted.name, 16);
+	}
+
+	typed->name[strcspn(typed->name, " /")] = '\0';
+
+	if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
+		archive_handle->action_header(typed);
+		if (archive_handle->sub_archive) {
+			while (archive_handle->action_data_subarchive(archive_handle->sub_archive) == EXIT_SUCCESS);
+		} else {
+			archive_handle->action_data(archive_handle);
+		}
+	} else {
+		data_skip(archive_handle);
+	}
+
+	archive_handle->offset += typed->size;
+	/* Set the file pointer to the correct spot, we may have been reading a compressed file */
+	lseek(archive_handle->src_fd, archive_handle->offset, SEEK_SET);
+
+	return EXIT_SUCCESS;
+}