Merge branch '2022-12-05-add-IPv6-support'

To quote the author:
This patch set adds basic IPv6 support to U-boot.
It is based on Chris's Packham patches
(https://lists.denx.de/pipermail/u-boot/2017-January/279366.html)
Chris's patches were taken as base. There were efforts to launch it on
HiFive SiFive Unmatched board but the board didn't work well. The code was
refactored, fixed some bugs as CRC for little-endian, some parts were implemented in
our own way, something was taken from Linux. Finally we did manual tests and the
board worked well.

Testing was done on HiFive SiFive Unmatched board (RISC-V)

2 files changed, 110 insertions, 6 deletions

diff --git a/lib/net_utils.c b/lib/net_utils.c
index 72a3b098a70..4283c13a31d 100644
--- a/lib/net_utils.c
+++ b/lib/net_utils.c
@@ -11,6 +11,7 @@
 
 #include <common.h>
 #include <net.h>
+#include <net6.h>
 
 struct in_addr string_to_ip(const char *s)
 {
@@ -43,6 +44,114 @@ struct in_addr string_to_ip(const char *s)
 	return addr;
 }
 
+#if IS_ENABLED(CONFIG_IPV6)
+int string_to_ip6(const char *str, size_t len, struct in6_addr *addr)
+{
+	int colon_count = 0;
+	int found_double_colon = 0;
+	int xstart = 0;		/* first zero (double colon) */
+	int section_num = 7;	/* num words the double colon represents */
+	int i;
+	const char *s = str;
+	const char *const e = s + len;
+	struct in_addr zero_ip = {.s_addr = 0};
+
+	if (!str)
+		return -1;
+
+	/* First pass, verify the syntax and locate the double colon */
+	while (s < e) {
+		while (s < e && isxdigit((int)*s))
+			s++;
+		if (*s == '\0')
+			break;
+		if (*s != ':') {
+			if (*s == '.' && section_num >= 2) {
+				struct in_addr v4;
+
+				while (s != str && *(s - 1) != ':')
+					--s;
+				v4 = string_to_ip(s);
+				if (memcmp(&zero_ip, &v4,
+					   sizeof(struct in_addr)) != 0) {
+					section_num -= 2;
+					break;
+				}
+			}
+			/* This could be a valid address */
+			break;
+		}
+		if (s == str) {
+			/* The address begins with a colon */
+			if (*++s != ':')
+				/* Must start with a double colon or a number */
+				goto out_err;
+		} else {
+			s++;
+			if (found_double_colon)
+				section_num--;
+			else
+				xstart++;
+		}
+
+		if (*s == ':') {
+			if (found_double_colon)
+				/* Two double colons are not allowed */
+				goto out_err;
+			found_double_colon = 1;
+			section_num -= xstart;
+			s++;
+		}
+
+		if (++colon_count == 7)
+			/* Found all colons */
+			break;
+		++s;
+	}
+
+	if (colon_count == 0)
+		goto out_err;
+	if (*--s == ':')
+		section_num++;
+
+	/* Second pass, read the address */
+	s = str;
+	for (i = 0; i < 8; i++) {
+		int val = 0;
+		char *end;
+
+		if (found_double_colon &&
+		    i >= xstart && i < xstart + section_num) {
+			addr->s6_addr16[i] = 0;
+			continue;
+		}
+		while (*s == ':')
+			s++;
+
+		if (i == 6 && isdigit((int)*s)) {
+			struct in_addr v4 = string_to_ip(s);
+
+			if (memcmp(&zero_ip, &v4,
+				   sizeof(struct in_addr)) != 0) {
+				/* Ending with :IPv4-address */
+				addr->s6_addr32[3] = v4.s_addr;
+				break;
+			}
+		}
+
+		val = simple_strtoul(s, &end, 16);
+		if (end != e && *end != '\0' && *end != ':')
+			goto out_err;
+		addr->s6_addr16[i] = htons(val);
+		s = end;
+	}
+	return 0;
+
+out_err:
+	return -1;
+}
+#endif
+
 void string_to_enetaddr(const char *addr, uint8_t *enetaddr)
 {
 	char *end;
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index fe06aa2d711..530d8088c7f 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -450,10 +450,6 @@ static char *uuid_string(char *buf, char *end, u8 *addr, int field_width,
  *       decimal for v4 and colon separated network-order 16 bit hex for v6)
  * - 'i' [46] for 'raw' IPv4/IPv6 addresses, IPv6 omits the colons, IPv4 is
  *       currently the same
- *
- * Note: IPv6 support is currently if(0)'ed out. If you ever need
- * %pI6, please add an IPV6 Kconfig knob, make your code select or
- * depend on that, and change the 0 below to CONFIG_IS_ENABLED(IPV6).
  */
 static char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 		int field_width, int precision, int flags)
@@ -498,8 +494,7 @@ static char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 		flags |= SPECIAL;
 		/* Fallthrough */
 	case 'I':
-		/* %pI6 currently unused */
-		if (0 && fmt[1] == '6')
+		if (IS_ENABLED(CONFIG_IPV6) && fmt[1] == '6')
 			return ip6_addr_string(buf, end, ptr, field_width,
 					       precision, flags);
 		if (fmt[1] == '4')