lib: new defaults logic

Since we've been writing out "frr version" and "frr defaults" for about
a year and a half now, we can now actually use them to manage defaults.

Signed-off-by: David Lamparter <equinox@diac24.net>

6 files changed, 376 insertions, 17 deletions

diff --git a/lib/command.c b/lib/command.c
index 9238ae412..d2145d9f5 100644
--- a/lib/command.c
+++ b/lib/command.c
@@ -1575,18 +1575,6 @@ DEFUN (show_version,
 	return CMD_SUCCESS;
 }
 
-/* "Set" version ... ignore version tags */
-DEFUN (frr_version_defaults,
-       frr_version_defaults_cmd,
-       "frr <version|defaults> LINE...",
-       "FRRouting global parameters\n"
-       "version configuration was written by\n"
-       "set of configuration defaults used\n"
-       "version string\n")
-{
-	return CMD_SUCCESS;
-}
-
 /* Help display function for all node. */
 DEFUN (config_help,
        config_help_cmd,
@@ -1721,8 +1709,10 @@ static int vty_write_config(struct vty *vty)
 		vty_out(vty, "!\n");
 	}
 
+	if (strcmp(frr_defaults_version(), FRR_VER_SHORT))
+		vty_out(vty, "! loaded from %s\n", frr_defaults_version());
 	vty_out(vty, "frr version %s\n", FRR_VER_SHORT);
-	vty_out(vty, "frr defaults %s\n", DFLT_NAME);
+	vty_out(vty, "frr defaults %s\n", frr_defaults_profile());
 	vty_out(vty, "!\n");
 
 	for (i = 0; i < vector_active(cmdvec); i++)
@@ -2941,7 +2931,6 @@ void cmd_init(int terminal)
 	install_element(CONFIG_NODE, &no_hostname_cmd);
 	install_element(CONFIG_NODE, &domainname_cmd);
 	install_element(CONFIG_NODE, &no_domainname_cmd);
-	install_element(CONFIG_NODE, &frr_version_defaults_cmd);
 
 	if (terminal > 0) {
 		install_element(CONFIG_NODE, &debug_memstats_cmd);
diff --git a/lib/defaults.c b/lib/defaults.c
index cfc8fa27f..8a1cfebe1 100644
--- a/lib/defaults.c
+++ b/lib/defaults.c
@@ -18,9 +18,20 @@
 #include <zebra.h>
 
 #include "defaults.h"
-#include "libfrr.h"
 #include "version.h"
 
+static char df_version[128] = FRR_VER_SHORT, df_profile[128] = DFLT_NAME;
+static struct frr_default *dflt_first = NULL, **dflt_next = &dflt_first;
+
+/* these are global for all FRR daemons.  they have to be, since we write an
+ * integrated config with the same value for all daemons.
+ */
+const char *frr_defaults_profiles[] = {
+	"traditional",
+	"datacenter",
+	NULL,
+};
+
 static int version_value(int ch)
 {
 	/* non-ASCII shouldn't happen */
@@ -73,3 +84,142 @@ int frr_version_cmp(const char *aa, const char *bb)
 	}
 	return 0;
 }
+
+static void frr_default_apply_one(struct frr_default *dflt, bool check);
+
+void frr_default_add(struct frr_default *dflt)
+{
+	dflt->next = NULL;
+	*dflt_next = dflt;
+	dflt_next = &dflt->next;
+
+	frr_default_apply_one(dflt, true);
+}
+
+static bool frr_match_version(const char *name, const char *vspec,
+			      const char *version, bool check)
+{
+	int cmp;
+	static struct spec {
+		const char *str;
+		bool dir, eq;
+	} *s, specs[] = {
+		{"<=", -1, 1},
+		{">=", 1, 1},
+		{"==", 0, 1},
+		{"<", -1, 0},
+		{">", 1, 0},
+		{"=", 0, 1},
+		{NULL, 0, 0},
+	};
+
+	if (!vspec)
+		/* NULL = all versions */
+		return true;
+
+	for (s = specs; s->str; s++)
+		if (!strncmp(s->str, vspec, strlen(s->str)))
+			break;
+	if (!s->str) {
+		if (check)
+			fprintf(stderr, "invalid version specifier for %s: %s",
+				name, vspec);
+		/* invalid version spec, never matches */
+		return false;
+	}
+
+	vspec += strlen(s->str);
+	while (isspace((unsigned char)*vspec))
+		vspec++;
+
+	cmp = frr_version_cmp(version, vspec);
+	if (cmp == s->dir || (s->eq && cmp == 0))
+		return true;
+
+	return false;
+}
+
+static void frr_default_apply_one(struct frr_default *dflt, bool check)
+{
+	struct frr_default_entry *entry = dflt->entries;
+	struct frr_default_entry *dfltentry = NULL, *saveentry = NULL;
+
+	for (; entry->match_version || entry->match_profile; entry++) {
+		if (entry->match_profile
+			&& strcmp(entry->match_profile, df_profile))
+			continue;
+
+		if (!dfltentry && frr_match_version(dflt->name,
+				entry->match_version, df_version, check))
+			dfltentry = entry;
+		if (!saveentry && frr_match_version(dflt->name,
+				entry->match_version, FRR_VER_SHORT, check))
+			saveentry = entry;
+
+		if (dfltentry && saveentry && !check)
+			break;
+	}
+	/* found default or arrived at last entry that has NULL,NULL spec */
+
+	if (!dfltentry)
+		dfltentry = entry;
+	if (!saveentry)
+		saveentry = entry;
+
+	if (dflt->dflt_str)
+		*dflt->dflt_str = dfltentry->val_str;
+	if (dflt->dflt_long)
+		*dflt->dflt_long = dfltentry->val_long;
+	if (dflt->dflt_ulong)
+		*dflt->dflt_ulong = dfltentry->val_ulong;
+	if (dflt->dflt_float)
+		*dflt->dflt_float = dfltentry->val_float;
+	if (dflt->save_str)
+		*dflt->save_str = saveentry->val_str;
+	if (dflt->save_long)
+		*dflt->save_long = saveentry->val_long;
+	if (dflt->save_ulong)
+		*dflt->save_ulong = saveentry->val_ulong;
+	if (dflt->save_float)
+		*dflt->save_float = saveentry->val_float;
+}
+
+void frr_defaults_apply(void)
+{
+	struct frr_default *dflt;
+
+	for (dflt = dflt_first; dflt; dflt = dflt->next)
+		frr_default_apply_one(dflt, false);
+}
+
+bool frr_defaults_profile_valid(const char *profile)
+{
+	const char **p;
+
+	for (p = frr_defaults_profiles; *p; p++)
+		if (!strcmp(profile, *p))
+			return true;
+	return false;
+}
+
+const char *frr_defaults_version(void)
+{
+	return df_version;
+}
+
+const char *frr_defaults_profile(void)
+{
+	return df_profile;
+}
+
+void frr_defaults_version_set(const char *version)
+{
+	strlcpy(df_version, version, sizeof(df_version));
+	frr_defaults_apply();
+}
+
+void frr_defaults_profile_set(const char *profile)
+{
+	strlcpy(df_profile, profile, sizeof(df_profile));
+	frr_defaults_apply();
+}
diff --git a/lib/defaults.h b/lib/defaults.h
index c21534150..ad2f1ad2e 100644
--- a/lib/defaults.h
+++ b/lib/defaults.h
@@ -18,6 +18,142 @@
 #ifndef _FRR_DEFAULTS_H
 #define _FRR_DEFAULTS_H
 
+#include "config.h"
+#include "compiler.h"
+
+#ifdef HAVE_DATACENTER
+
+#define DFLT_BGP_IMPORT_CHECK			1
+#define DFLT_BGP_TIMERS_CONNECT			10
+#define DFLT_BGP_HOLDTIME			9
+#define DFLT_BGP_KEEPALIVE			3
+#define DFLT_BGP_LOG_NEIGHBOR_CHANGES		1
+#define DFLT_BGP_SHOW_HOSTNAME			1
+#define DFLT_BGP_DETERMINISTIC_MED		1
+
+#define DFLT_OSPF_LOG_ADJACENCY_CHANGES		1
+#define DFLT_OSPF6_LOG_ADJACENCY_CHANGES	1
+
+#else  /* !HAVE_DATACENTER */
+
+#define DFLT_BGP_IMPORT_CHECK			0
+#define DFLT_BGP_TIMERS_CONNECT			120
+#define DFLT_BGP_HOLDTIME			180
+#define DFLT_BGP_KEEPALIVE			60
+#define DFLT_BGP_LOG_NEIGHBOR_CHANGES		0
+#define DFLT_BGP_SHOW_HOSTNAME			0
+#define DFLT_BGP_DETERMINISTIC_MED		0
+
+#define DFLT_OSPF_LOG_ADJACENCY_CHANGES		0
+#define DFLT_OSPF6_LOG_ADJACENCY_CHANGES	0
+
+#endif /* !HAVE_DATACENTER */
+
+/* frr_default wraps information about a default that has different
+ * values depending on FRR version or default-set
+ *
+ * frr_default_entry describes one match rule and the resulting value;
+ * entries are evaluated in order and the first matching is used.
+ *
+ * If both match_version and match_profile are specified, they must both
+ * match.  A NULL value matches everything.
+ */
+struct frr_default_entry {
+	/* syntax: "(<|<=|==|>=|>) [whitespace] version", e.g.
+	 *   ">= 6.1-dev" "<6.0"
+	 */
+	const char *match_version;
+	/* exact profile string to compare against */
+	const char *match_profile;
+
+	/* value to use */
+	const char *val_str;
+	long val_long;
+	unsigned long val_ulong;
+	float val_float;
+};
+
+/* one struct frr_default exists for each malleable default value */
+struct frr_default {
+	struct frr_default *next;
+
+	/* for UI/debug use */
+	const char *name;
+
+	/* the following two sets of variables differ because the written
+	 * config always targets the *current* FRR version
+	 *
+	 * e.g. if you load a config that has "frr version 5.0" on 6.0
+	 *   *dflt_long => set to the default value in 5.0
+	 *   *save_long => set to the default value in 6.0
+	 * config save will write "frr version 6.0" with 6.0 defaults
+	 */
+
+	/* variable holding the default value for reading/use */
+	const char **dflt_str;
+	long *dflt_long;
+	unsigned long *dflt_ulong;
+	float *dflt_float;
+
+	/* variable to use when comparing for config save */
+	const char **save_str;
+	long *save_long;
+	unsigned long *save_ulong;
+	float *save_float;
+
+	struct frr_default_entry entries[];
+};
+
+#define _FRR_CFG_DEFAULT(type, typname, varname, ...) \
+	static type DFLT_##varname;                                            \
+	static type SAVE_##varname;                                            \
+	static struct frr_default _dflt_##varname = {                          \
+		.name = #varname,                                              \
+		.dflt_##typname = &DFLT_##varname,                             \
+		.save_##typname = &SAVE_##varname,                             \
+		.entries = { __VA_ARGS__ },                                    \
+	};                                                                     \
+	static void _dfltinit_##varname(void)                                  \
+		__attribute__((_CONSTRUCTOR(1000)));                           \
+	static void _dfltinit_##varname(void)                                  \
+	{                                                                      \
+		frr_default_add(&_dflt_##varname);                             \
+	}
+
+/* use:
+ *   FRR_CFG_DEFAULT_LONG(SHARP_BLUNTNESS,
+ *	{ .val_long = 2, .match_version = ">= 10.0" },
+ *	{ .val_long = 1, .match_profile = "datacenter" },
+ *	{ .val_long = 0 },
+ *   )
+ *
+ * This will create DFLT_SHARP_BLUNTNESS and SAVE_SHARP_BLUNTNESS variables.
+ *
+ * Note: preprocessor defines cannot be used as variable names because they
+ * will be expanded and blow up with a compile error.  Use an enum or add an
+ * extra _ at the beginning (e.g. _SHARP_BLUNTNESS => DFLT__SHARP_BLUNTNESS)
+ */
+#define FRR_CFG_DEFAULT_LONG(varname, ...) \
+	_FRR_CFG_DEFAULT(long, long, varname, ## __VA_ARGS__)
+#define FRR_CFG_DEFAULT_ULONG(varname, ...) \
+	_FRR_CFG_DEFAULT(unsigned long, ulong, varname, ## __VA_ARGS__)
+#define FRR_CFG_DEFAULT_FLOAT(varname, ...) \
+	_FRR_CFG_DEFAULT(float, float, varname, ## __VA_ARGS__)
+#define FRR_CFG_DEFAULT_STR(varname, ...) \
+	_FRR_CFG_DEFAULT(const char *, str, varname, ## __VA_ARGS__)
+
+
+/* daemons don't need to call any of these, libfrr handles that */
+extern void frr_default_add(struct frr_default *dflt);
+extern void frr_defaults_version_set(const char *version);
+extern void frr_defaults_profile_set(const char *profile);
+extern const char *frr_defaults_version(void);
+extern const char *frr_defaults_profile(void);
+extern void frr_defaults_apply(void);
+
+extern const char *frr_defaults_profiles[];
+extern bool frr_defaults_profile_valid(const char *profile);
+
 /* like strcmp(), but with version ordering */
 extern int frr_version_cmp(const char *aa, const char *bb);
 
diff --git a/lib/lib_vty.c b/lib/lib_vty.c
index 932b46501..787da08e2 100644
--- a/lib/lib_vty.c
+++ b/lib/lib_vty.c
@@ -35,6 +35,7 @@
 #include "log.h"
 #include "memory.h"
 #include "module.h"
+#include "defaults.h"
 #include "lib_vty.h"
 
 /* Looking up memory status from vty interface. */
@@ -177,8 +178,60 @@ DEFUN_NOSH (show_modules,
 	return CMD_SUCCESS;
 }
 
+DEFUN (frr_defaults,
+       frr_defaults_cmd,
+       "frr defaults PROFILE...",
+       "FRRouting global parameters\n"
+       "set of configuration defaults used\n"
+       "profile string\n")
+{
+	char *profile = argv_concat(argv, argc, 2);
+	int rv = CMD_SUCCESS;
+
+	if (!frr_defaults_profile_valid(profile)) {
+		vty_out(vty, "%% WARNING: profile %s is not known in this version\n",
+			profile);
+		rv = CMD_WARNING;
+	}
+	frr_defaults_profile_set(profile);
+	XFREE(MTYPE_TMP, profile);
+	return rv;
+}
+
+DEFUN (frr_version,
+       frr_version_cmd,
+       "frr version VERSION...",
+       "FRRouting global parameters\n"
+       "version configuration was written by\n"
+       "version string\n")
+{
+	char *version = argv_concat(argv, argc, 2);
+
+	frr_defaults_version_set(version);
+	XFREE(MTYPE_TMP, version);
+	return CMD_SUCCESS;
+}
+
+static void defaults_autocomplete(vector comps, struct cmd_token *token)
+{
+	const char **p;
+
+	for (p = frr_defaults_profiles; *p; p++)
+		vector_set(comps, XSTRDUP(MTYPE_COMPLETION, *p));
+}
+
+static const struct cmd_variable_handler default_var_handlers[] = {
+	{.tokenname = "PROFILE", .completions = defaults_autocomplete},
+	{.completions = NULL},
+};
+
 void lib_cmd_init(void)
 {
+	cmd_variable_handler_register(default_var_handlers);
+
+	install_element(CONFIG_NODE, &frr_defaults_cmd);
+	install_element(CONFIG_NODE, &frr_version_cmd);
+
 	install_element(VIEW_NODE, &show_memory_cmd);
 	install_element(VIEW_NODE, &show_modules_cmd);
 }
diff --git a/lib/libfrr.c b/lib/libfrr.c
index 1dd7e932c..4fb43edff 100644
--- a/lib/libfrr.c
+++ b/lib/libfrr.c
@@ -43,6 +43,7 @@
 #include "debug.h"
 #include "frrcu.h"
 #include "frr_pthread.h"
+#include "defaults.h"
 
 DEFINE_HOOK(frr_late_init, (struct thread_master * tm), (tm))
 DEFINE_KOOH(frr_early_fini, (), ())
@@ -104,6 +105,7 @@ static const struct option lo_always[] = {
 	{"version", no_argument, NULL, 'v'},
 	{"daemon", no_argument, NULL, 'd'},
 	{"module", no_argument, NULL, 'M'},
+	{"profile", required_argument, NULL, 'F'},
 	{"vty_socket", required_argument, NULL, OPTION_VTYSOCK},
 	{"moduledir", required_argument, NULL, OPTION_MODULEDIR},
 	{"log", required_argument, NULL, OPTION_LOG},
@@ -112,11 +114,12 @@ static const struct option lo_always[] = {
 	{"command-log-always", no_argument, NULL, OPTION_LOGGING},
 	{NULL}};
 static const struct optspec os_always = {
-	"hvdM:",
+	"hvdM:F:",
 	"  -h, --help         Display this help and exit\n"
 	"  -v, --version      Print program version\n"
 	"  -d, --daemon       Runs in daemon mode\n"
 	"  -M, --module       Load specified module\n"
+	"  -F, --profile      Use specified configuration profile\n"
 	"      --vty_socket   Override vty socket path\n"
 	"      --moduledir    Override modules directory\n"
 	"      --log          Set Logging to stdout, syslog, or file:<name>\n"
@@ -389,6 +392,32 @@ static int frr_opt(int opt)
 		*modnext = oc;
 		modnext = &oc->next;
 		break;
+	case 'F':
+		if (!frr_defaults_profile_valid(optarg)) {
+			const char **p;
+			FILE *ofd = stderr;
+
+			if (!strcmp(optarg, "help"))
+				ofd = stdout;
+			else
+				fprintf(stderr,
+					"The \"%s\" configuration profile is not valid for this FRR version.\n",
+					optarg);
+
+			fprintf(ofd, "Available profiles are:\n");
+			for (p = frr_defaults_profiles; *p; p++)
+				fprintf(ofd, "%s%s\n",
+					strcmp(*p, DFLT_NAME) ? "   " : " * ",
+					*p);
+
+			if (ofd == stdout)
+				exit(0);
+			fprintf(ofd, "\n");
+			errors++;
+			break;
+		}
+		frr_defaults_profile_set(optarg);
+		break;
 	case 'i':
 		if (di->flags & FRR_NO_CFG_PID_DRY)
 			return 1;
@@ -607,6 +636,7 @@ struct thread_master *frr_init(void)
 	dir = di->module_path ? di->module_path : frr_moduledir;
 
 	srandom(time(NULL));
+	frr_defaults_apply();
 
 	if (di->instance) {
 		snprintf(frr_protonameinst, sizeof(frr_protonameinst), "%s[%u]",
diff --git a/lib/northbound_cli.c b/lib/northbound_cli.c
index 009e5bd82..17dc25628 100644
--- a/lib/northbound_cli.c
+++ b/lib/northbound_cli.c
@@ -21,6 +21,7 @@
 
 #include "libfrr.h"
 #include "version.h"
+#include "defaults.h"
 #include "log.h"
 #include "lib_errors.h"
 #include "command.h"
@@ -486,7 +487,7 @@ static void nb_cli_show_config_cmds(struct vty *vty, struct nb_config *config,
 	vty_out(vty, "Configuration:\n");
 	vty_out(vty, "!\n");
 	vty_out(vty, "frr version %s\n", FRR_VER_SHORT);
-	vty_out(vty, "frr defaults %s\n", DFLT_NAME);
+	vty_out(vty, "frr defaults %s\n", frr_defaults_profile());
 
 	LY_TREE_FOR (config->dnode, root)
 		nb_cli_show_dnode_cmds(vty, root, with_defaults);