Packet location updates

This patch includes various bugfixes in the packet location parser.
Namely it removes two memory leaks if parsing fails. The parser is
correctly quit if an allocation error occurs and it is no longer
possible to add duplicates.

It removes the possibility to differ between net and host byteorder.
This is better done in the actual classifiers as it makes more sense
to specify this together with the value to compare against.

The patch also extends the API to add new packet locations via
rtnl_pktloc_add().

It introduces reference counting, therefore you now have to give
back packet locations with rtnl_pktloc_put() after looking them up
with rtnl_pktloc_lookup(). But you are allowed to keep using them
if the packet location file has been reread.

The packet location file now also understands "eth", "ip", and
"tcp" for "link", "net", and "transport".

A --list option has been added to nl-pktloc-lookup to list all
packet location definitions

A --u32=VALUE option has been added to let nl-pktloc-lookup print
the definition in iproute2's u32 selector style.

A manual page has been written for nl-pktloc-lookup.

Finally, nl-pktloc-lookup has been made installable.

1 files changed, 105 insertions, 6 deletions

diff --git a/src/nl-pktloc-lookup.c b/src/nl-pktloc-lookup.c
index 09b04b2..dc6154f 100644
--- a/src/nl-pktloc-lookup.c
+++ b/src/nl-pktloc-lookup.c
@@ -14,24 +14,123 @@
 
 static void print_usage(void)
 {
-	printf("Usage: nl-pktloc-lookup <name>\n");
+printf(
+"Usage: nl-pktloc-lookup [OPTIONS] <name>\n"
+"\n"
+"OPTIONS\n"
+" -h, --help                Show this help text.\n"
+" -v, --version             Show versioning information.\n"
+" -l, --list                List all packet location definitions.\n"
+"     --u32=VALUE	    Print in iproute2's u32 selector style\n"
+"\n"
+"\n"
+"EXAMPLE\n"
+"   $ nl-pktloc-lookup ip.dst\n"
+"   $ nl-pktloc-lookup --list\n"
+"\n"
+);
 	exit(0);
 }
 
+static const char *align_txt[] = {
+	[TCF_EM_ALIGN_U8] = "u8",
+	[TCF_EM_ALIGN_U16] = "u16",
+	[TCF_EM_ALIGN_U32] = "u32"
+};
+
+static uint32_t align_mask[] = {
+	[TCF_EM_ALIGN_U8] = 0xff,
+	[TCF_EM_ALIGN_U16] = 0xffff,
+	[TCF_EM_ALIGN_U32] = 0xffffffff,
+};
+
+static const char *layer_txt[] = {
+	[TCF_LAYER_LINK] = "eth",
+	[TCF_LAYER_NETWORK] = "ip",
+	[TCF_LAYER_TRANSPORT] = "tcp"
+};
+
+static void dump_u32_style(struct rtnl_pktloc *loc, uint32_t value)
+{
+	if (loc->layer == TCF_LAYER_LINK)
+		nl_cli_fatal(EINVAL, "u32 does not support link "
+				"layer locations.");
+
+	printf("%s %x %x at %s%u\n",
+		align_txt[loc->align],
+		value, loc->mask ? loc->mask : align_mask[loc->align],
+		loc->layer == TCF_LAYER_TRANSPORT ? "nexthdr+" : "",
+		loc->offset);
+}
+
+static void dump_loc(struct rtnl_pktloc *loc)
+{
+	printf("%s = %s at %s+%u %#x\n",
+		loc->name, align_txt[loc->align],
+		layer_txt[loc->layer], loc->offset, loc->mask);
+}
+
+static void list_cb(struct rtnl_pktloc *loc, void *arg)
+{
+	printf("%-26s %-5s %3s+%-4u %#-10x %u\n",
+		loc->name, align_txt[loc->align],
+		layer_txt[loc->layer], loc->offset,
+		loc->mask, loc->refcnt);
+}
+
+static void do_list(void)
+{
+	printf("name                      align  offset  mask     refcnt\n");
+	printf("---------------------------------------------------------\n");
+
+	rtnl_pktloc_foreach(&list_cb, NULL);
+}
+
 int main(int argc, char *argv[])
 {
 	struct rtnl_pktloc *loc;
-	int err;
+	int err, ustyle = 0;
+	uint32_t uvalue = 0;
+
+	for (;;) {
+		int c, optidx = 0;
+		enum {
+			ARG_U32 = 257,
+		};
+		static struct option long_opts[] = {
+			{ "help", 0, 0, 'h' },
+			{ "version", 0, 0, 'v' },
+			{ "list", 0, 0, 'l' },
+			{ "u32", 1, 0, ARG_U32 },
+			{ 0, 0, 0, 0 }
+		};
+	
+		c = getopt_long(argc, argv, "hvl", long_opts, &optidx);
+		if (c == -1)
+			break;
+
+		switch (c) {
+		case 'h': print_usage(); break;
+		case 'v': nl_cli_print_version(); break;
+		case 'l': do_list(); exit(0);
+		case ARG_U32:
+			ustyle = 1;
+			uvalue = nl_cli_parse_u32(optarg);
+			break;
+		}
+ 	}
 
-	if (argc < 2)
+	if (optind >= argc)
 		print_usage();
 
-	if ((err = rtnl_pktloc_lookup(argv[1], &loc)) < 0)
+	if ((err = rtnl_pktloc_lookup(argv[optind++], &loc)) < 0)
 		nl_cli_fatal(err, "Unable to lookup packet location: %s",
 			nl_geterror(err));
 
-	printf("%s: %u %u+%u 0x%x %u\n", loc->name, loc->align,
-		loc->layer, loc->offset, loc->mask, loc->flags);
+	if (ustyle)
+		dump_u32_style(loc, uvalue);
+	else
+		dump_loc(loc);
 
 	return 0;
 }