testing at sparc

Hi there!

I've been testing nftables at sparc, looking for endianess issues. Unfortunately, weird things happened.

Adding some rule:

% nft add table filter
% nft add chain filter input
% nft add rule filter input tcp dport 22 counter
% nft list table filter
table ip filter {

  chain input {
    payload @th,16,16 0x0 [invalid type] counter packets 0 bytes 0

}
}

However, matching happened when I generated some traffic.

Also, compiling the nft cli tool:

% make

-e   SUBDIR src/
-e   LEX src/scanner.l
-e   DEP src/scanner.c
-e   YACC src/parser.y
-e   DEP src/parser.c
-e   DEP src/mnl.c
-e   DEP src/erec.c
-e   DEP src/utils.c
-e   DEP src/gmputil.c
-e   DEP src/rbtree.c
-e   DEP src/segtree.c
-e   DEP src/netlink_delinearize.c
-e   DEP src/netlink_linearize.c
-e   DEP src/netlink.c
-e   DEP src/ct.c
-e   DEP src/meta.c
-e   DEP src/exthdr.c
-e   DEP src/payload.c
-e   DEP src/proto.c
-e   DEP src/evaluate.c
-e   DEP src/expression.c
-e   DEP src/datatype.c
-e   DEP src/statement.c
-e   DEP src/rule.c
-e   DEP src/cli.c
-e   DEP src/main.c
-e   LEX src/scanner.l
-e   DEP src/scanner.c
-e   YACC src/parser.y
-e   DEP src/parser.c
-e   DEP src/scanner.c
-e   CC src/main.c

src/main.c: In function 'nft_netlink':
src/main.c:176:2: warning: cast increases required alignment of target type [-Wcast-align]
src/main.c:176:2: warning: cast increases required alignment of target type [-Wcast-align]
src/main.c:194:2: warning: cast increases required alignment of target type [-Wcast-align]
src/main.c:194:2: warning: cast increases required alignment of target type [-Wcast-align]
src/main.c:194:2: warning: cast increases required alignment of target type [-Wcast-align]
src/main.c:195:3: warning: cast increases required alignment of target type [-Wcast-align]
src/main.c:195:3: warning: cast increases required alignment of target type [-Wcast-align]
src/main.c:209:2: warning: cast increases required alignment of target type [-Wcast-align]
src/main.c:209:2: warning: cast increases required alignment of target type [-Wcast-align]
src/main.c:209:2: warning: cast increases required alignment of target type [-Wcast-align]
-e CC src/cli.c
-e CC src/rule.c
src/rule.c: In function 'set_lookup':
src/rule.c:89:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:89:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c: In function 'rule_print':
src/rule.c:154:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:154:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c: In function 'scope_release':
src/rule.c:172:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:172:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:172:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c: In function 'symbol_lookup':
src/rule.c:196:3: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:196:3: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c: In function 'chain_free':
src/rule.c:261:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:261:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:261:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c: In function 'chain_lookup':
src/rule.c:277:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:277:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c: In function 'chain_print':
src/rule.c:353:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:353:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c: In function 'table_free':
src/rule.c:379:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:379:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:379:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c: In function 'table_lookup':
src/rule.c:397:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:397:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c: In function 'table_print':
src/rule.c:413:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:413:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:420:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:420:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c: In function 'do_add_table':
src/rule.c:520:3: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:520:3: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:525:3: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:525:3: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c: In function 'do_list_sets':
src/rule.c:595:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:595:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:595:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c: In function 'do_command_list':
src/rule.c:645:4: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:645:4: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:671:3: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:671:3: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:681:3: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:681:3: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:692:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:692:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:692:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:705:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:705:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:705:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:710:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:710:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:710:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c: In function 'payload_try_merge':
src/rule.c:843:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:843:2: warning: cast increases required alignment of target type [-Wcast-align]
src/rule.c:843:2: warning: cast increases required alignment of target type [-Wcast-align]
-e CC src/statement.c
src/statement.c: In function 'stmt_list_free':
src/statement.c:45:2: warning: cast increases required alignment of target type [-Wcast-align]
src/statement.c:45:2: warning: cast increases required alignment of target type [-Wcast-align]
src/statement.c:45:2: warning: cast increases required alignment of target type [-Wcast-align]
-e CC src/datatype.c
src/datatype.c: In function 'ipaddr_type_parse':
src/datatype.c:385:11: warning: cast increases required alignment of target type [-Wcast-align]
src/datatype.c: In function 'ip6addr_type_parse':
src/datatype.c:443:11: warning: cast increases required alignment of target type [-Wcast-align]
src/datatype.c: In function 'inet_service_type_parse':
src/datatype.c:555:11: warning: cast increases required alignment of target type [-Wcast-align]
src/datatype.c: In function 'concat_type_alloc':
src/datatype.c:858:2: warning: cast increases required alignment of target type [-Wcast-align]
src/datatype.c:858:2: warning: cast increases required alignment of target type [-Wcast-align]
-e CC src/expression.c
src/expression.c: In function 'compound_expr_clone':
src/expression.c:647:2: warning: cast increases required alignment of target type [-Wcast-align]
src/expression.c:647:2: warning: cast increases required alignment of target type [-Wcast-align]
src/expression.c: In function 'compound_expr_destroy':
src/expression.c:655:2: warning: cast increases required alignment of target type [-Wcast-align]
src/expression.c:655:2: warning: cast increases required alignment of target type [-Wcast-align]
src/expression.c:655:2: warning: cast increases required alignment of target type [-Wcast-align]
src/expression.c: In function 'compound_expr_print':
src/expression.c:664:2: warning: cast increases required alignment of target type [-Wcast-align]
src/expression.c:664:2: warning: cast increases required alignment of target type [-Wcast-align]
src/expression.c: In function 'set_expr_set_type':
src/expression.c:738:2: warning: cast increases required alignment of target type [-Wcast-align]
src/expression.c:738:2: warning: cast increases required alignment of target type [-Wcast-align]
-e CC src/evaluate.c
src/evaluate.c: In function 'get_set':
src/evaluate.c:134:9: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c: In function 'list_member_evaluate':
src/evaluate.c:592:22: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c: In function 'expr_evaluate_concat':
src/evaluate.c:612:2: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c:612:2: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c:612:2: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c: In function 'expr_evaluate_list':
src/evaluate.c:648:2: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c:648:2: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c:648:2: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c: In function 'expr_evaluate_set':
src/evaluate.c:676:2: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c:676:2: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c:676:2: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c: In function 'binop_transfer':
src/evaluate.c:846:3: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c:846:3: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c:851:3: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c:851:3: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c:851:3: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c: In function 'rule_evaluate':
src/evaluate.c:1276:2: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c:1276:2: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c: In function 'chain_evaluate':
src/evaluate.c:1342:2: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c:1342:2: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c: In function 'table_evaluate':
src/evaluate.c:1356:2: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c:1356:2: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c:1361:2: warning: cast increases required alignment of target type [-Wcast-align]
src/evaluate.c:1361:2: warning: cast increases required alignment of target type [-Wcast-align]

-e   CC src/proto.c
-e   CC src/payload.c
-e   CC src/exthdr.c
-e   CC src/meta.c
-e   CC src/ct.c
-e   CC src/netlink.c

src/netlink.c: In function 'netlink_gen_concat_data':
src/netlink.c:218:2: warning: cast increases required alignment of target type [-Wcast-align]
src/netlink.c:218:2: warning: cast increases required alignment of target type [-Wcast-align]
src/netlink.c:225:3: warning: cast increases required alignment of target type [-Wcast-align]
src/netlink.c:225:3: warning: cast increases required alignment of target type [-Wcast-align]
src/netlink.c: In function 'netlink_add_rule_list':
src/netlink.c:336:2: warning: cast increases required alignment of target type [-Wcast-align]
src/netlink.c:336:2: warning: cast increases required alignment of target type [-Wcast-align]
src/netlink.c: In function 'netlink_list_chains':
src/netlink.c:562:2: warning: cast increases required alignment of target type [-Wcast-align]
src/netlink.c:562:2: warning: cast increases required alignment of target type [-Wcast-align]
src/netlink.c: In function 'alloc_setelem_cache':
src/netlink.c:913:2: warning: cast increases required alignment of target type [-Wcast-align]
src/netlink.c:913:2: warning: cast increases required alignment of target type [-Wcast-align]
-e CC src/netlink_linearize.c
src/netlink_linearize.c: In function 'netlink_gen_concat':
src/netlink_linearize.c:49:2: warning: cast increases required alignment of target type [-Wcast-align] src/netlink_linearize.c:49:2: warning: cast increases required alignment of target type [-Wcast-align] src/netlink_linearize.c: In function 'netlink_linearize_rule':
src/netlink_linearize.c:720:2: warning: cast increases required alignment of target type [-Wcast-align] src/netlink_linearize.c:720:2: warning: cast increases required alignment of target type [-Wcast-align]
-e CC src/netlink_delinearize.c
src/netlink_delinearize.c: In function 'payload_match_postprocess':
src/netlink_delinearize.c:639:3: warning: cast increases required alignment of target type [-Wcast-align] src/netlink_delinearize.c:639:3: warning: cast increases required alignment of target type [-Wcast-align] src/netlink_delinearize.c: In function 'expr_postprocess':
src/netlink_delinearize.c:783:3: warning: cast increases required alignment of target type [-Wcast-align] src/netlink_delinearize.c:783:3: warning: cast increases required alignment of target type [-Wcast-align] src/netlink_delinearize.c: In function 'rule_parse_postprocess':
src/netlink_delinearize.c:880:2: warning: cast increases required alignment of target type [-Wcast-align] src/netlink_delinearize.c:880:2: warning: cast increases required alignment of target type [-Wcast-align] src/netlink_delinearize.c:880:2: warning: cast increases required alignment of target type [-Wcast-align]
-e CC src/segtree.c
src/segtree.c: In function 'seg_tree_init':
src/segtree.c:71:10: warning: cast increases required alignment of target type [-Wcast-align]
src/segtree.c: In function 'ei_lookup':
src/segtree.c:119:8: warning: cast increases required alignment of target type [-Wcast-align]
src/segtree.c: In function '__ei_insert':
src/segtree.c:145:8: warning: cast increases required alignment of target type [-Wcast-align]
src/segtree.c: In function 'set_to_segtree':
src/segtree.c:355:2: warning: cast increases required alignment of target type [-Wcast-align]
src/segtree.c:355:2: warning: cast increases required alignment of target type [-Wcast-align]
src/segtree.c:355:2: warning: cast increases required alignment of target type [-Wcast-align]
src/segtree.c: In function 'segtree_linearize':
src/segtree.c:397:2: warning: cast increases required alignment of target type [-Wcast-align]
src/segtree.c: In function 'set_to_intervals':
src/segtree.c:482:2: warning: cast increases required alignment of target type [-Wcast-align]
src/segtree.c:482:2: warning: cast increases required alignment of target type [-Wcast-align]
src/segtree.c:482:2: warning: cast increases required alignment of target type [-Wcast-align]
src/segtree.c: In function 'interval_map_decompose':
src/segtree.c:540:2: warning: cast increases required alignment of target type [-Wcast-align]
src/segtree.c:540:2: warning: cast increases required alignment of target type [-Wcast-align]
src/segtree.c:540:2: warning: cast increases required alignment of target type [-Wcast-align]

-e   CC src/rbtree.c
-e   CC src/gmputil.c
-e   CC src/utils.c
-e   CC src/erec.c

src/erec.c: In function 'erec_print_list':
src/erec.c:158:2: warning: cast increases required alignment of target type [-Wcast-align]
src/erec.c:158:2: warning: cast increases required alignment of target type [-Wcast-align]
src/erec.c:158:2: warning: cast increases required alignment of target type [-Wcast-align]
-e CC src/mnl.c
src/mnl.c: In function 'mnl_nft_socket_sendmsg':
src/mnl.c:217:2: warning: cast increases required alignment of target type [-Wcast-align]
src/mnl.c:217:2: warning: cast increases required alignment of target type [-Wcast-align]
src/mnl.c:217:2: warning: cast increases required alignment of target type [-Wcast-align]
src/mnl.c: In function 'mnl_batch_talk':
src/mnl.c:264:26: warning: cast increases required alignment of target type [-Wcast-align]
-e CC src/parser.c
src/parser.y: In function 'nft_parse':
src/parser.y:1045:5: warning: cast increases required alignment of target type [-Wcast-align]
src/parser.y:1045:5: warning: cast increases required alignment of target type [-Wcast-align]

-e   CC src/scanner.c
-e   LD src/nft
-e   SUBDIR files/
-e   SUBDIR doc/
-e   MAN doc/nftables.8

Arturo Borrero González
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Great, I meant to do this for a long time.

So it appears we only have a problem in userspace? That's at least partially good news. Could you provide access to that machine for debugging?

It appears all of these originate from the list iterator macros. I guess its container_of() and the cast to (type *)(char *)ptr ...

Ok here's a patch to partially fix the problem. We have a similar case in the kernel when calculating the mask for the cmp_fast expression, as well as some problems in data import/export in userspace. I'll take care of those next.

I'm not entirely happy with the naming in this patch, better suggestions are welcome.

From: Patrick McHardy <[email protected]>
Date: Fri, 11 Apr 2014 17:09:15 +0200
Subject: [PATCH] expression: fix constant expression allocation on big endian

When allocating a constant expression, a pointer to the data is passed to the allocation function. When the variable used to store the data is larger than the size of the data type, this fails on big endian since the most significant bytes (being zero) come first.

Add a helper function to calculate the proper address for the cases where this is needed.

This currently affects symbolic tables for values < u64 and payload dependency generation for protocol values < u32.

---
 include/utils.h | 13 +++++++++++++
 src/datatype.c  |  3 ++-
 src/payload.c   |  4 +++-
 3 files changed, 18 insertions(+), 2 deletions(-)

index 88ee0c9..93f9f06 100644
@@ -46,6 +46,19 @@
 	typeof( ((type *)0)->member ) *__mptr = (ptr);		\
 	(type *)( (void *)__mptr - offsetof(type,member) );})
 
+/**
+ * Return a pointer to a constant variable of a size smaller than the variable.
+ */
+#ifdef __BIG_ENDIAN
+#define constant_data_ptr(val, len) \
+	((void *)&val + sizeof(val) - (len) / BITS_PER_BYTE)
+#elif __LITTLE_ENDIAN
+#define constant_data_ptr(val, len) \
+	((void *)&val)
+#else
+error "byteorder undefined"
+#endif
+
 #define field_sizeof(t, f)	(sizeof(((t *)NULL)->f))
 #define array_size(arr)		(sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
 #define div_round_up(n, d)	(((n) + (d) - 1) / (d))

index ac42faa..367c3ea 100644
@@ -15,6 +15,7 @@
 #include <errno.h>
 #include <netdb.h>
 #include <arpa/inet.h>
+#include <asm/byteorder.h>
 #include <linux/types.h>
 #include <linux/netfilter.h>
 

@@ -124,7 +125,7 @@ struct error_record *symbolic_constant_parse(const struct expr *sym,
 
 	*res = constant_expr_alloc(&sym->location, dtype,
 				   dtype->byteorder, dtype->size,
-				   &s->value);
+				   constant_data_ptr(s->value, dtype->size));
 	return NULL;
 }
 

index 427080c..e2a9407 100644
@@ -17,6 +17,7 @@
 #include <string.h>
 #include <net/if_arp.h>
 #include <arpa/inet.h>
+#include <asm/byteorder.h>
 #include <linux/netfilter.h>
 
 #include <rule.h>

@@ -209,7 +210,8 @@ int payload_gen_dependency(struct eval_ctx *ctx, const struct expr *expr,
 
 	right = constant_expr_alloc(&expr->location, tmpl->dtype,
 				    BYTEORDER_HOST_ENDIAN,
-				    tmpl->len, &protocol);
+				    tmpl->len,
+				    constant_data_ptr(protocol, tmpl->len));
 
 	dep = relational_expr_alloc(&expr->location, OP_EQ, left, right);
 	left->ops->pctx_update(&ctx->pctx, dep);

1.9.0