ustar: Support reading GNU long name/link records

2 files changed, 105 insertions, 30 deletions

diff --git a/opkg-opk/ustar.c b/opkg-opk/ustar.c
index 5a202c7..67236cc 100644
--- a/opkg-opk/ustar.c
+++ b/opkg-opk/ustar.c
@@ -74,7 +74,32 @@ opkg_opk_ustar_init(struct opkg_opk_gzip *gzip)
 }
 
 static int
-_opkg_opk_ustar_next(struct opkg_opk_ustar *ustar)
+_opkg_opk_ustar_read_gnu_long_records(struct opkg_opk_ustar *ustar,
+		char **gnu_long_buf)
+{
+	char   *gnu_long_buf_sub;
+	char   *read_buf;
+	size_t  size;
+
+	gnu_long_buf_sub = *gnu_long_buf = malloc(ustar->data_size_remaining);
+	if (*gnu_long_buf == NULL) {
+		return OPKG_OPK_ERROR;
+	}
+
+	while (ustar->data_size_remaining > 0) {
+		if (opkg_opk_ustar_read(ustar, &read_buf, &size) ==
+				OPKG_OPK_ERROR) {
+			return OPKG_OPK_ERROR;
+		}
+		memcpy(gnu_long_buf_sub, read_buf, size);
+		gnu_long_buf_sub += size;
+	}
+
+	return OPKG_OPK_OK;
+}
+
+static int
+_opkg_opk_ustar_next(struct opkg_opk_ustar *ustar, char **name, char **linkname)
 {
 	char          *end;
 	uint32_t       chksum_got;
@@ -82,6 +107,11 @@ _opkg_opk_ustar_next(struct opkg_opk_ustar *ustar)
 	size_t         i;
 	unsigned char *header_uc;
 
+	*name     = NULL;
+	*linkname = NULL;
+
+ again:  /* Go to here if a GNU long name/link is read. */
+
 	/* Seek through data records until next header record. */
 	while (ustar->data_size_remaining > 0) {
 		if (opkg_opk_ustar_read(ustar, NULL, NULL) == OPKG_OPK_ERROR) {
@@ -131,7 +161,48 @@ _opkg_opk_ustar_next(struct opkg_opk_ustar *ustar)
 		return OPKG_OPK_ERROR;
 	}
 
-	/* Depending on type, get size. */
+	/* Fill (possibly long) name and/or linkname buffers for caller. */
+	if (*name == NULL) {
+		/* No GNU long name */
+		if (ustar->header.prefix[0] != '\0') {
+			*name = malloc(sizeof(ustar->header.prefix) +
+					sizeof(ustar->header.name) + 1);
+			if (*name == NULL) {
+				if (*linkname != NULL) {
+					free(*linkname);
+				}
+				return OPKG_OPK_ERROR;
+			}
+			sprintf(*name, "%s/%s", ustar->header.prefix,
+					ustar->header.name);
+		} else {
+			*name = malloc(sizeof(ustar->header.name) + 1);
+			if (*name == NULL) {
+				if (*linkname != NULL) {
+					free(*linkname);
+				}
+				return OPKG_OPK_ERROR;
+			}
+			/* Use memcpy() because ustar->header.name may not be
+			 * NUL-terminated. */
+			memcpy(*name, ustar->header.name,
+					sizeof(ustar->header.name));
+			(*name)[sizeof(ustar->header.name)] = '\0';
+		}
+	}
+	if (*linkname == NULL && *ustar->header.typeflag == '2') {
+		/* Symbolic link without GNU long link name */
+		*linkname = malloc(sizeof(ustar->header.linkname) + 1);
+		if (*linkname == NULL) {
+			free(*name);
+			return OPKG_OPK_ERROR;
+		}
+		strncpy(*linkname, ustar->header.linkname,
+				sizeof(ustar->header.linkname));
+		(*linkname)[sizeof(ustar->header.linkname)] = '\0';
+	}
+
+	/* Depending on type, get size or GNU long name/link records. */
 	switch (*ustar->header.typeflag) {
 		case '0':  /* Regular file */
 		case '7':  /* High-performance or regular file */
@@ -153,6 +224,19 @@ _opkg_opk_ustar_next(struct opkg_opk_ustar *ustar)
 			ustar->data_size_remaining = 0;
 			break;
 		case '1':  /* Link */
+			return OPKG_OPK_ERROR;  /* Unsupported */
+		case 'L':  /* GNU long name */
+			if (_opkg_opk_ustar_read_gnu_long_records(ustar,
+						name) != OPKG_OPK_OK) {
+				return OPKG_OPK_ERROR;
+			}
+			goto again;
+		case 'K':  /* GNU long link */
+			if (_opkg_opk_ustar_read_gnu_long_records(ustar,
+						linkname) != OPKG_OPK_OK) {
+				return OPKG_OPK_ERROR;
+			}
+			goto again;
 		default:   /* Reserved */
 			return OPKG_OPK_ERROR;  /* Unsupported */
 	}
@@ -167,42 +251,35 @@ opkg_opk_ustar_list(struct opkg_opk_ustar *ustar,
 	int   ret;
 	char *end;
 
-	/* Get next header record, if any. */
-	if ((ret = _opkg_opk_ustar_next(ustar)) != OPKG_OPK_OK) {
-		return ret;  /* Error or end of archive */
-	}
-
 	/* Allocate outward-facing member information structure. */
 	*member = malloc(sizeof(**member));
 	if (*member == NULL) {
 		return OPKG_OPK_ERROR;
 	}
 
-	/* Set name, mode, size, mtime, type, linkname, uname, gname, devmajor,
-	 * and devminor. */
-	if (ustar->header.prefix[0] != '\0') {
-		sprintf((*member)->name, "%s/%s",
-				ustar->header.prefix, ustar->header.name);
-	} else {
-		/* Use memcpy() because ustar->header.name may not be
-		 * NUL-terminated. */
-		memcpy((*member)->name, ustar->header.name,
-				sizeof(ustar->header.name));
-		(*member)->name[sizeof(ustar->header.name)] = '\0';
+	/* Get next header record, if any. */
+	if ((ret = _opkg_opk_ustar_next(ustar, &((*member)->name),
+					&((*member)->linkname))) != OPKG_OPK_OK)
+	{
+		free(*member);
+		return ret;  /* Error or end of archive */
 	}
-	/* Assumes mode and mtime are NUL-terminated.  Not required by POSIX,
+
+	/* Set mode, size, mtime, type, uname, gname, devmajor, and devminor.
+	 * Name and linkname are already set by _opkg_opk_ustar_next().
+	 * Assumes mode and mtime are NUL-terminated.  Not required by POSIX,
 	 * but done by GNU and BB tar and opkg_opk_ustar_write_header(). */
 	(*member)->mode = strtol(ustar->header.mode, &end,
 			OPKG_OPK_USTAR_NUM_BASE_);
 	if (*end != '\0') {
-		free(*member);
+		opkg_opk_ustar_member_free(*member);
 		return OPKG_OPK_ERROR;
 	}
 	(*member)->size = ustar->data_size_remaining;
 	(*member)->mtime = strtol(ustar->header.mtime, &end,
 			OPKG_OPK_USTAR_NUM_BASE_);
 	if (*end != '\0') {
-		free(*member);
+		opkg_opk_ustar_member_free(*member);
 		return OPKG_OPK_ERROR;
 	}
 	switch (*ustar->header.typeflag) {
@@ -212,10 +289,6 @@ opkg_opk_ustar_list(struct opkg_opk_ustar *ustar,
 			break;
 		case '2':  /* Symbolic link */
 			(*member)->type = 'l';
-			strncpy((*member)->linkname, ustar->header.linkname,
-					sizeof(ustar->header.linkname));
-			(*member)->linkname[sizeof((*member)->linkname) - 1] =
-				'\0';
 			break;
 		case '3':  /* Character special file */
 			(*member)->type = 'c';
@@ -231,7 +304,7 @@ opkg_opk_ustar_list(struct opkg_opk_ustar *ustar,
 			break;
 		case '1':  /* Link */
 		default:   /* Reserved */
-			free(*member);
+			opkg_opk_ustar_member_free(*member);
 			return OPKG_OPK_ERROR;  /* Unsupported */
 	}
 	strncpy((*member)->uname, ustar->header.uname,
@@ -241,13 +314,13 @@ opkg_opk_ustar_list(struct opkg_opk_ustar *ustar,
 	(*member)->devmajor = strtol(ustar->header.devmajor, &end,
 			OPKG_OPK_USTAR_NUM_BASE_);
 	if (*end != '\0') {
-		free(*member);
+		opkg_opk_ustar_member_free(*member);
 		return OPKG_OPK_ERROR;
 	}
 	(*member)->devminor = strtol(ustar->header.devminor, &end,
 			OPKG_OPK_USTAR_NUM_BASE_);
 	if (*end != '\0') {
-		free(*member);
+		opkg_opk_ustar_member_free(*member);
 		return OPKG_OPK_ERROR;
 	}
 
@@ -442,6 +515,8 @@ opkg_opk_ustar_write_trailer(struct opkg_opk_ustar *ustar)
 void
 opkg_opk_ustar_member_free(struct opkg_opk_ustar_member *member)
 {
+	free(member->name);
+	free(member->linkname);
 	free(member);
 }
 
diff --git a/opkg-opk/ustar.h b/opkg-opk/ustar.h
index 234964c..9dd5194 100644
--- a/opkg-opk/ustar.h
+++ b/opkg-opk/ustar.h
@@ -32,12 +32,12 @@
 struct opkg_opk_ustar;
 
 struct opkg_opk_ustar_member {
-	char                          name    [OPKG_OPK_USTAR_NAME_SIZE];
+	char                         *name;
 	uint16_t                      mode;
 	uint64_t                      size;
 	uint64_t                      mtime;
 	char                          type;
-	char                          linkname[OPKG_OPK_USTAR_LINKNAME_SIZE];
+	char                         *linkname;
 	char                          uname   [32];
 	char                          gname   [32];
 	uint32_t                      devmajor;