confd: migrate infix-system:motd -> infix-system:motd-banner

Inspired by openconfig-system[1], except the infix-system type is binary
to allow encoding an entire file, with optional control characters.

The openconfig-system model also carries login-banner, which is displayed
before login.  This could be added later to infix-system to let the user
set an OpenSSH login Banner.

[1]:  https://openconfig.net/projects/models/schemadocs/yangdoc/openconfig-system.html

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

src/confd/bin/bootstrap

@@ -225,7 +225,7 @@ sysrepoctl -s $SEARCH							\
 	   -i infix-lldp@2023-08-23.yang	-g wheel -p 0660	\
 	   -i infix-dhcp-client@2024-01-30.yang -g wheel -p 0660	\
 	   -i infix-shell-type@2023-08-21.yang	-g wheel -p 0660	\
-	   -i infix-system@2023-10-19.yang	-g wheel -p 0660	\
+	   -i infix-system@2024-02-29.yang	-g wheel -p 0660	\
 	   -i infix-services@2023-10-16.yang	-g wheel -p 0660	\
 	   -i ieee802-ethernet-interface@2019-06-21.yang -g wheel -p 0660 \
 	   -i infix-ethernet-interface@2024-02-27.yang -g wheel -p 0660 \

src/confd/bin/gen-motd

@@ -6,7 +6,7 @@ if [ -f /etc/motd ]; then
     cat <<EOF
 {
   "ietf-system:system": {
-    "infix-system:motd": "$(sed ':a;N;$!ba;s/\n/\\n/g;s/\t/\\t/g' /etc/motd)"
+    "infix-system:motd-banner": "$(base64 -w0 /etc/motd)"
   }
 }
 EOF

src/confd/src/ietf-system.c

@@ -13,6 +13,7 @@
 #include <srx/srx_module.h>
 #include <srx/srx_val.h>
 
+#include "base64.h"
 #include "core.h"
 
 #define XPATH_BASE_    "/ietf-system:system"
@@ -1028,12 +1029,63 @@ static int change_motd(sr_session_ctx_t *session, uint32_t sub_id, const char *m
 	if (message) {
 		rc = writesf(message, "w", "%s", fn);
 		free(message);
+	}
+
+	if (rc) {
+		ERRNO("failed saving %s", fn);
+		return SR_ERR_SYS;
+	}
+
+	return SR_ERR_OK;
+}
+
+static int change_motd_banner(sr_session_ctx_t *session, uint32_t sub_id, const char *module,
+		       const char *xpath, sr_event_t event, unsigned request_id, void *priv)
+{
+	const char *fn = "/etc/motd";
+	unsigned char *raw, *txt;
+	size_t txt_len;
+	char *legacy;
+	int rc = 0;
+
+	/* Ignore all events except SR_EV_DONE */
+	if (event != SR_EV_DONE)
+		return SR_ERR_OK;
+
+	legacy = srx_get_str(session, "/ietf-system:system/infix-sys:motd");
+	if (legacy) {
+		NOTE("Legacy /system/motd exists, skipping %s", xpath);
+		free(legacy);
+		return SR_ERR_OK;
+	}
+
+	raw = (unsigned char *)srx_get_str(session, "%s", xpath);
+	if (raw) {
+		txt = base64_decode(raw, strlen((char *)raw), &txt_len);
+		if (!txt) {
+			ERRNO("failed base64 decoding of %s", xpath);
+			rc = -1;
+		} else {
+			FILE *fp = fopen(fn, "w");
+
+			if (!fp) {
+				rc = -1;
+			} else {
+				if (fwrite(txt, txt_len, sizeof(txt[0]), fp) != txt_len)
+					rc = -1;
+				fclose(fp);
+			}
+
+			free(txt);
+		}
+
+		free(raw);
 	} else {
 		(void)remove(fn);
 	}
 
 	if (rc) {
-		ERROR("failed writing /etc/motd: %s", strerror(errno));
+		ERRNO("failed saving %s", fn);
 		return SR_ERR_SYS;
 	}
 
@@ -1137,6 +1189,7 @@ int ietf_system_init(struct confd *confd)
 	REGISTER_CHANGE(confd->session, "ietf-system", XPATH_AUTH_, 0, change_auth, confd, &confd->sub);
 	REGISTER_CHANGE(confd->session, "ietf-system", XPATH_BASE_"/hostname", 0, change_hostname, confd, &confd->sub);
 	REGISTER_CHANGE(confd->session, "ietf-system", XPATH_BASE_"/infix-system:motd", 0, change_motd, confd, &confd->sub);
+	REGISTER_CHANGE(confd->session, "ietf-system", XPATH_BASE_"/infix-system:motd-banner", 0, change_motd_banner, confd, &confd->sub);
 	REGISTER_CHANGE(confd->session, "ietf-system", XPATH_BASE_"/clock", 0, change_clock, confd, &confd->sub);
 	REGISTER_CHANGE(confd->session, "ietf-system", XPATH_BASE_"/ntp", 0, change_ntp, confd, &confd->sub);
 	REGISTER_CHANGE(confd->session, "ietf-system", XPATH_BASE_"/dns-resolver", 0, change_dns, confd, &confd->sub);

src/confd/yang/infix-system@2024-02-29.yang

@@ -19,6 +19,11 @@ module infix-system {
   contact      "kernelkit@googlegroups.com";
   description  "Infix augments and deviations to ietf-system.";
 
+  revision 2024-02-29 {
+    description "Mark infix-sys:motd as deprecated, to be replaced with type binary.";
+    reference "internal";
+  }
+
   revision 2023-10-19 {
     description "Change deviation for timezone-utc-offset from unsupported to Etc+/-HOUR
                 - Unit is set to hours (tzdata compatibility)
@@ -26,6 +31,7 @@ module infix-system {
 
     reference "internal";
   }
+
   revision 2023-08-15 {
     description "Add support for user login shell.
 
@@ -60,9 +66,31 @@ module infix-system {
 
   augment "/sys:system" {
     description "Augment of ietf-system for modifying /etc/motd.";
+
     leaf motd {
+      description "Legacy MotD (Message of the Day), shown after login.
+
+                   Please note, this is obsolete!  When set it overrides the
+                   'motd-banner' setting for backwards compatibility.
+
+                   Instead, use 'motd-banner', which takes a base64 encoded
+                   text file as an argument.  For CLI users, edit with the
+                   'text-editor motd-banner' command.";
+      status obsolete;      // Replaced with motd-banner (binary)
       type string;
-      description "Set the MotD (Message of the Day), shown after login";
+    }
+
+    // From openconfig-system, which also has login-banner (TODO)
+    leaf motd-banner {
+      description "Message of the Day (MotD), shown after SSH/console login.
+
+                   Base64 encoded (binary) file contents for the system file
+                   /etc/motd, displayed after SSH/console login.
+
+                   They system may append additional standard information such
+                   as the current system date and time, uptime, last login
+                   timestamp, etc.";
+      type binary;
     }
   }