tools lib traceevent: Add support for IP address formats

Add helpers for the following kernel formats:
  %pi4 print an IPv4 address with leading zeros
  %pI4 print an IPv4 address without leading zeros
  %pi6 print an IPv6 address without colons
  %pI6 print an IPv6 address with colons
  %pI6c print an IPv6 address in compressed form with colons
  %pISpc print an IP address from a sockaddr

Allows these formats to be used in tracepoints.

Quite a bit of this is adapted from code in lib/vsprintf.c.

v4:
- fixed pI6c description in git commit message per Valdis' comment

v3:
- use of 'c' and 'p' requires 'I'

v2:
- pass ptr+1 to print_ip_arg per Namhyung's comments
- added field length checks to sockaddr function

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1418955071-36241-1-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/traceevent/event-parse.c

@@ -32,6 +32,7 @@
 #include <stdint.h>
 #include <limits.h>
 
+#include <netinet/ip6.h>
 #include "event-parse.h"
 #include "event-utils.h"
 
@@ -4149,6 +4150,324 @@ static void print_mac_arg(struct trace_seq *s, int mac, void *data, int size,
 	trace_seq_printf(s, fmt, buf[0], buf[1], buf[2], buf[3], buf[4], buf[5]);
 }
 
+static void print_ip4_addr(struct trace_seq *s, char i, unsigned char *buf)
+{
+	const char *fmt;
+
+	if (i == 'i')
+		fmt = "%03d.%03d.%03d.%03d";
+	else
+		fmt = "%d.%d.%d.%d";
+
+	trace_seq_printf(s, fmt, buf[0], buf[1], buf[2], buf[3]);
+}
+
+static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
+{
+	return ((unsigned long)(a->s6_addr32[0] | a->s6_addr32[1]) |
+		(unsigned long)(a->s6_addr32[2] ^ htonl(0x0000ffff))) == 0UL;
+}
+
+static inline bool ipv6_addr_is_isatap(const struct in6_addr *addr)
+{
+	return (addr->s6_addr32[2] | htonl(0x02000000)) == htonl(0x02005EFE);
+}
+
+static void print_ip6c_addr(struct trace_seq *s, unsigned char *addr)
+{
+	int i, j, range;
+	unsigned char zerolength[8];
+	int longest = 1;
+	int colonpos = -1;
+	uint16_t word;
+	uint8_t hi, lo;
+	bool needcolon = false;
+	bool useIPv4;
+	struct in6_addr in6;
+
+	memcpy(&in6, addr, sizeof(struct in6_addr));
+
+	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
+
+	memset(zerolength, 0, sizeof(zerolength));
+
+	if (useIPv4)
+		range = 6;
+	else
+		range = 8;
+
+	/* find position of longest 0 run */
+	for (i = 0; i < range; i++) {
+		for (j = i; j < range; j++) {
+			if (in6.s6_addr16[j] != 0)
+				break;
+			zerolength[i]++;
+		}
+	}
+	for (i = 0; i < range; i++) {
+		if (zerolength[i] > longest) {
+			longest = zerolength[i];
+			colonpos = i;
+		}
+	}
+	if (longest == 1)		/* don't compress a single 0 */
+		colonpos = -1;
+
+	/* emit address */
+	for (i = 0; i < range; i++) {
+		if (i == colonpos) {
+			if (needcolon || i == 0)
+				trace_seq_printf(s, ":");
+			trace_seq_printf(s, ":");
+			needcolon = false;
+			i += longest - 1;
+			continue;
+		}
+		if (needcolon) {
+			trace_seq_printf(s, ":");
+			needcolon = false;
+		}
+		/* hex u16 without leading 0s */
+		word = ntohs(in6.s6_addr16[i]);
+		hi = word >> 8;
+		lo = word & 0xff;
+		if (hi)
+			trace_seq_printf(s, "%x%02x", hi, lo);
+		else
+			trace_seq_printf(s, "%x", lo);
+
+		needcolon = true;
+	}
+
+	if (useIPv4) {
+		if (needcolon)
+			trace_seq_printf(s, ":");
+		print_ip4_addr(s, 'I', &in6.s6_addr[12]);
+	}
+
+	return;
+}
+
+static void print_ip6_addr(struct trace_seq *s, char i, unsigned char *buf)
+{
+	int j;
+
+	for (j = 0; j < 16; j += 2) {
+		trace_seq_printf(s, "%02x%02x", buf[j], buf[j+1]);
+		if (i == 'I' && j < 14)
+			trace_seq_printf(s, ":");
+	}
+}
+
+/*
+ * %pi4   print an IPv4 address with leading zeros
+ * %pI4   print an IPv4 address without leading zeros
+ * %pi6   print an IPv6 address without colons
+ * %pI6   print an IPv6 address with colons
+ * %pI6c  print an IPv6 address in compressed form with colons
+ * %pISpc print an IP address based on sockaddr; p adds port.
+ */
+static int print_ipv4_arg(struct trace_seq *s, const char *ptr, char i,
+			  void *data, int size, struct event_format *event,
+			  struct print_arg *arg)
+{
+	unsigned char *buf;
+
+	if (arg->type == PRINT_FUNC) {
+		process_defined_func(s, data, size, event, arg);
+		return 0;
+	}
+
+	if (arg->type != PRINT_FIELD) {
+		trace_seq_printf(s, "ARG TYPE NOT FIELD BUT %d", arg->type);
+		return 0;
+	}
+
+	if (!arg->field.field) {
+		arg->field.field =
+			pevent_find_any_field(event, arg->field.name);
+		if (!arg->field.field) {
+			do_warning("%s: field %s not found",
+				   __func__, arg->field.name);
+			return 0;
+		}
+	}
+
+	buf = data + arg->field.field->offset;
+
+	if (arg->field.field->size != 4) {
+		trace_seq_printf(s, "INVALIDIPv4");
+		return 0;
+	}
+	print_ip4_addr(s, i, buf);
+
+	return 0;
+}
+
+static int print_ipv6_arg(struct trace_seq *s, const char *ptr, char i,
+			  void *data, int size, struct event_format *event,
+			  struct print_arg *arg)
+{
+	char have_c = 0;
+	unsigned char *buf;
+	int rc = 0;
+
+	/* pI6c */
+	if (i == 'I' && *ptr == 'c') {
+		have_c = 1;
+		ptr++;
+		rc++;
+	}
+
+	if (arg->type == PRINT_FUNC) {
+		process_defined_func(s, data, size, event, arg);
+		return rc;
+	}
+
+	if (arg->type != PRINT_FIELD) {
+		trace_seq_printf(s, "ARG TYPE NOT FIELD BUT %d", arg->type);
+		return rc;
+	}
+
+	if (!arg->field.field) {
+		arg->field.field =
+			pevent_find_any_field(event, arg->field.name);
+		if (!arg->field.field) {
+			do_warning("%s: field %s not found",
+				   __func__, arg->field.name);
+			return rc;
+		}
+	}
+
+	buf = data + arg->field.field->offset;
+
+	if (arg->field.field->size != 16) {
+		trace_seq_printf(s, "INVALIDIPv6");
+		return rc;
+	}
+
+	if (have_c)
+		print_ip6c_addr(s, buf);
+	else
+		print_ip6_addr(s, i, buf);
+
+	return rc;
+}
+
+static int print_ipsa_arg(struct trace_seq *s, const char *ptr, char i,
+			  void *data, int size, struct event_format *event,
+			  struct print_arg *arg)
+{
+	char have_c = 0, have_p = 0;
+	unsigned char *buf;
+	struct sockaddr_storage *sa;
+	int rc = 0;
+
+	/* pISpc */
+	if (i == 'I') {
+		if (*ptr == 'p') {
+			have_p = 1;
+			ptr++;
+			rc++;
+		}
+		if (*ptr == 'c') {
+			have_c = 1;
+			ptr++;
+			rc++;
+		}
+	}
+
+	if (arg->type == PRINT_FUNC) {
+		process_defined_func(s, data, size, event, arg);
+		return rc;
+	}
+
+	if (arg->type != PRINT_FIELD) {
+		trace_seq_printf(s, "ARG TYPE NOT FIELD BUT %d", arg->type);
+		return rc;
+	}
+
+	if (!arg->field.field) {
+		arg->field.field =
+			pevent_find_any_field(event, arg->field.name);
+		if (!arg->field.field) {
+			do_warning("%s: field %s not found",
+				   __func__, arg->field.name);
+			return rc;
+		}
+	}
+
+	sa = (struct sockaddr_storage *) (data + arg->field.field->offset);
+
+	if (sa->ss_family == AF_INET) {
+		struct sockaddr_in *sa4 = (struct sockaddr_in *) sa;
+
+		if (arg->field.field->size < sizeof(struct sockaddr_in)) {
+			trace_seq_printf(s, "INVALIDIPv4");
+			return rc;
+		}
+
+		print_ip4_addr(s, i, (unsigned char *) &sa4->sin_addr);
+		if (have_p)
+			trace_seq_printf(s, ":%d", ntohs(sa4->sin_port));
+
+
+	} else if (sa->ss_family == AF_INET6) {
+		struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *) sa;
+
+		if (arg->field.field->size < sizeof(struct sockaddr_in6)) {
+			trace_seq_printf(s, "INVALIDIPv6");
+			return rc;
+		}
+
+		if (have_p)
+			trace_seq_printf(s, "[");
+
+		buf = (unsigned char *) &sa6->sin6_addr;
+		if (have_c)
+			print_ip6c_addr(s, buf);
+		else
+			print_ip6_addr(s, i, buf);
+
+		if (have_p)
+			trace_seq_printf(s, "]:%d", ntohs(sa6->sin6_port));
+	}
+
+	return rc;
+}
+
+static int print_ip_arg(struct trace_seq *s, const char *ptr,
+			void *data, int size, struct event_format *event,
+			struct print_arg *arg)
+{
+	char i = *ptr;  /* 'i' or 'I' */
+	char ver;
+	int rc = 0;
+
+	ptr++;
+	rc++;
+
+	ver = *ptr;
+	ptr++;
+	rc++;
+
+	switch (ver) {
+	case '4':
+		rc += print_ipv4_arg(s, ptr, i, data, size, event, arg);
+		break;
+	case '6':
+		rc += print_ipv6_arg(s, ptr, i, data, size, event, arg);
+		break;
+	case 'S':
+		rc += print_ipsa_arg(s, ptr, i, data, size, event, arg);
+		break;
+	default:
+		return 0;
+	}
+
+	return rc;
+}
+
 static int is_printable_array(char *p, unsigned int len)
 {
 	unsigned int i;
@@ -4337,6 +4656,15 @@ static void pretty_print(struct trace_seq *s, void *data, int size, struct event
 					ptr++;
 					arg = arg->next;
 					break;
+				} else if (*(ptr+1) == 'I' || *(ptr+1) == 'i') {
+					int n;
+
+					n = print_ip_arg(s, ptr+1, data, size, event, arg);
+					if (n > 0) {
+						ptr += n;
+						arg = arg->next;
+						break;
+					}
 				}
 
 				/* fall through */