Merge branch 'netpoll-untangle-netconsole-and-netpoll'

Breno Leitao says:

====================
netpoll: Untangle netconsole and netpoll

Initially netpoll and netconsole were created together, and some
functions are in the wrong file. Seperate netconsole-only functions
in netconsole, avoiding exports.

1. Expose netpoll logging macros in the public header to enable consistent
   log formatting across netpoll consumers.

2. Relocate netconsole-specific functions from netpoll to the netconsole
   module where they are actually used, reducing unnecessary coupling.

3. Remove unnecessary function exports

4. Rename netpoll parsing functions in netconsole to better reflect their
   specific usage.

5. Create a test to check that cmdline works fine. This was in my todo
   list since [1], this was a good time to add it here to make sure this
   patchset doesn't regress.

PS: The code was split in a way that it is easy to review. When copying
the functions from netpoll to netconsole, I do not change than other
than adding `static`. This will make checkpatch unhappy, but, further
patches will address the issues. It is done this way to make it easy for
reviewers.

Link: https://lore.kernel.org/netdev/Z36TlACdNMwFD7wv@dev-ushankar.dev.purestorage.com/ [1]

v2: https://lore.kernel.org/20250611-rework-v2-0-ab1d92b458ca@debian.org
v1: https://lore.kernel.org/20250610-rework-v1-0-7cfde283f246@debian.org
====================

Link: https://patch.msgid.link/20250613-rework-v3-0-0752bf2e6912@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 134 insertions, 3 deletions

diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index 1eb678e07dd0..89afe127b46c 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -278,6 +278,23 @@ static void netconsole_process_cleanups_core(void)
 	mutex_unlock(&target_cleanup_list_lock);
 }
 
+static void netconsole_print_banner(struct netpoll *np)
+{
+	np_info(np, "local port %d\n", np->local_port);
+	if (np->ipv6)
+		np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6);
+	else
+		np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
+	np_info(np, "interface name '%s'\n", np->dev_name);
+	np_info(np, "local ethernet address '%pM'\n", np->dev_mac);
+	np_info(np, "remote port %d\n", np->remote_port);
+	if (np->ipv6)
+		np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6);
+	else
+		np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
+	np_info(np, "remote ethernet address %pM\n", np->remote_mac);
+}
+
 #ifdef	CONFIG_NETCONSOLE_DYNAMIC
 
 /*
@@ -534,10 +551,10 @@ static ssize_t enabled_store(struct config_item *item,
 		}
 
 		/*
-		 * Skip netpoll_parse_options() -- all the attributes are
+		 * Skip netconsole_parser_cmdline() -- all the attributes are
 		 * already configured via configfs. Just print them out.
 		 */
-		netpoll_print_options(&nt->np);
+		netconsole_print_banner(&nt->np);
 
 		ret = netpoll_setup(&nt->np);
 		if (ret)
@@ -1659,6 +1676,120 @@ static void write_msg(struct console *con, const char *msg, unsigned int len)
 	spin_unlock_irqrestore(&target_list_lock, flags);
 }
 
+static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
+{
+	const char *end;
+
+	if (!strchr(str, ':') &&
+	    in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
+		if (!*end)
+			return 0;
+	}
+	if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
+#if IS_ENABLED(CONFIG_IPV6)
+		if (!*end)
+			return 1;
+#else
+		return -1;
+#endif
+	}
+	return -1;
+}
+
+static int netconsole_parser_cmdline(struct netpoll *np, char *opt)
+{
+	bool ipversion_set = false;
+	char *cur = opt;
+	char *delim;
+	int ipv6;
+
+	if (*cur != '@') {
+		delim = strchr(cur, '@');
+		if (!delim)
+			goto parse_failed;
+		*delim = 0;
+		if (kstrtou16(cur, 10, &np->local_port))
+			goto parse_failed;
+		cur = delim;
+	}
+	cur++;
+
+	if (*cur != '/') {
+		ipversion_set = true;
+		delim = strchr(cur, '/');
+		if (!delim)
+			goto parse_failed;
+		*delim = 0;
+		ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
+		if (ipv6 < 0)
+			goto parse_failed;
+		else
+			np->ipv6 = (bool)ipv6;
+		cur = delim;
+	}
+	cur++;
+
+	if (*cur != ',') {
+		/* parse out dev_name or dev_mac */
+		delim = strchr(cur, ',');
+		if (!delim)
+			goto parse_failed;
+		*delim = 0;
+
+		np->dev_name[0] = '\0';
+		eth_broadcast_addr(np->dev_mac);
+		if (!strchr(cur, ':'))
+			strscpy(np->dev_name, cur, sizeof(np->dev_name));
+		else if (!mac_pton(cur, np->dev_mac))
+			goto parse_failed;
+
+		cur = delim;
+	}
+	cur++;
+
+	if (*cur != '@') {
+		/* dst port */
+		delim = strchr(cur, '@');
+		if (!delim)
+			goto parse_failed;
+		*delim = 0;
+		if (*cur == ' ' || *cur == '\t')
+			np_info(np, "warning: whitespace is not allowed\n");
+		if (kstrtou16(cur, 10, &np->remote_port))
+			goto parse_failed;
+		cur = delim;
+	}
+	cur++;
+
+	/* dst ip */
+	delim = strchr(cur, '/');
+	if (!delim)
+		goto parse_failed;
+	*delim = 0;
+	ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
+	if (ipv6 < 0)
+		goto parse_failed;
+	else if (ipversion_set && np->ipv6 != (bool)ipv6)
+		goto parse_failed;
+	else
+		np->ipv6 = (bool)ipv6;
+	cur = delim + 1;
+
+	if (*cur != 0) {
+		/* MAC address */
+		if (!mac_pton(cur, np->remote_mac))
+			goto parse_failed;
+	}
+
+	netconsole_print_banner(np);
+
+	return 0;
+
+ parse_failed:
+	np_info(np, "couldn't parse config at '%s'!\n", cur);
+	return -1;
+}
+
 /* Allocate new target (from boot/module param) and setup netpoll for it */
 static struct netconsole_target *alloc_param_target(char *target_config,
 						    int cmdline_count)
@@ -1688,7 +1819,7 @@ static struct netconsole_target *alloc_param_target(char *target_config,
 	}
 
 	/* Parse parameters and setup netpoll */
-	err = netpoll_parse_options(&nt->np, target_config);
+	err = netconsole_parser_cmdline(&nt->np, target_config);
 	if (err)
 		goto fail;