pingu: implement new config format

New format allows users to define interfaces and ping hosts separately.
This means we can run pingu in routing-only mode to set up and manage
route tables for multi-isp.

We allow the user config a preferred alternate route table for each
interface. If not configured, pingu will pick one.

Example interface definition looks like:

interface eth0 {
	route-table 10
}

Example host definition looks like:

host 192.168.0.1 {
	bind-interface eth0
}

1 files changed, 208 insertions, 0 deletions

diff --git a/pingu_conf.c b/pingu_conf.c
new file mode 100644
index 0000000..be92483
--- /dev/null
+++ b/pingu_conf.c
@@ -0,0 +1,208 @@
+
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "log.h"
+#include "pingu_iface.h"
+#include "pingu_host.h"
+#include "xlib.h"
+
+static float default_burst_interval = 30.0;
+static float default_timeout = 1.0;
+static int default_max_retries = 5;
+static int default_required_replies = 3;
+static char *default_up_action = NULL;
+static char *default_down_action = NULL;
+
+/* note: this overwrite the line buffer */
+static void parse_line(char *line, char **key, char **value)
+{
+	char *p;
+
+	(*value) = NULL;
+	(*key) = NULL;
+
+	/* strip comments and trailng \n */
+	p = strpbrk(line, "#\n");
+	if (p)
+		*p = '\0';
+
+	/* skip leading whitespace */
+	while (isspace(*line))
+		line++;
+	if (*line == '\0')
+		return;
+		
+	(*key) = line;
+
+	/* find space between keyword and value */
+	p = line;
+	while (!isspace(*p)) {
+		if (*p == '\0')
+			return;
+		p++;
+	}
+	*p++ = '\0';
+
+	/* find value */
+	while (isspace(*p))
+		p++;
+	if (*p == '\0')
+		return;
+
+	(*value) = p;
+}
+
+static FILE *pingu_conf_open(const char *filename)
+{
+	FILE *f = fopen(filename, "r");
+	if (f == NULL)
+		log_perror(filename);
+	return f;
+}
+
+static char *chomp_bracket(char *str)
+{
+	char *p = str;
+	/* chomp */
+	while (!isspace(*p))
+		p++;
+	*p = '\0';
+	return str;
+}
+
+static char *pingu_conf_get_key_value(FILE *f, char **key, char **value, int *lineno)
+{
+	static char line[1024];
+	char *k = NULL, *v = NULL;
+	while (k == NULL || *k == '\0') {
+		if (fgets(line, sizeof(line), f) == NULL)
+			return NULL;
+		(*lineno)++;
+		parse_line(line, &k, &v);
+	}
+	*key = k;
+	*value = v;
+	return line;
+}
+	
+		
+
+static int pingu_conf_read_iface(FILE *f, char *ifname, int *lineno)
+{
+	struct pingu_iface *iface;
+	char *key, *value;
+	
+	iface = pingu_iface_get_by_name(value);
+	if (iface != NULL) {
+		log_error("Interface %s already declared");
+		return -1;
+	}
+
+	iface = pingu_iface_get_by_name_or_new(ifname);
+	if (iface == NULL)
+		return -1;
+
+	while (pingu_conf_get_key_value(f, &key, &value, lineno)) {
+		if (key == NULL || key[0] == '}')
+			break;
+		if (strcmp(key, "route-table") == 0) {
+			pingu_iface_set_route_table(iface, atoi(value));
+		} else {
+			log_error("Unknown keyword '%s' on line %i", key,
+				  lineno);
+		}
+	}
+	return 0;
+}
+
+static int pingu_conf_read_host(FILE *f, char *hoststr, int *lineno)
+{
+	char *key, *value;
+	struct pingu_host *host;
+	
+	host = pingu_host_new(xstrdup(hoststr), default_burst_interval,
+			      default_max_retries, default_required_replies,
+			      default_timeout, default_up_action,
+			      default_down_action);
+	while (pingu_conf_get_key_value(f, &key, &value, lineno)) {
+		if (key == NULL || key[0] == '}')
+			break;
+		if (strcmp(key, "bind-interface") == 0) {
+			host->iface = pingu_iface_get_by_name_or_new(value);
+			if (host->iface == NULL) {
+				log_error("Undefined interface %s on line %i",
+					   value, lineno);
+				return -1;
+			}
+		} else if (strcmp(key, "label") == 0) {
+			host->label = xstrdup(value);
+		} else if (strcmp(key, "up-action") == 0) {
+			host->up_action = xstrdup(value);
+		} else if (strcmp(key, "down-action") == 0) {
+			host->down_action = xstrdup(value);
+		} else if (strcmp(key, "retry") == 0) {
+			host->max_retries = atoi(value);
+		} else if (strcmp(key, "required") == 0) {
+			host->required_replies = atoi(value);
+		} else if (strcmp(key, "timeout") == 0) {
+			host->timeout = atof(value);
+		} else if (strcmp(key, "interval") == 0) {
+			host->burst_interval = atof(value);
+		} else {
+			log_error("Unknown keyword '%s' on line %i", key,
+				  lineno);
+		}
+	}
+	if (host->iface == NULL)
+		host->iface = pingu_iface_get_by_name_or_new(NULL);
+	return 0;
+}
+
+int pingu_conf_read(const char *filename)
+{
+	int lineno = 0;
+	char line[256];
+	int r = 0;
+	FILE *f = pingu_conf_open(filename);
+	
+	if (f == NULL)
+		return -1;
+
+	while (fgets(line, sizeof(line), f)) {
+		char *key, *value;
+		lineno++;
+		parse_line(line, &key, &value);
+		if (key == NULL)
+			continue;
+		if (strcmp(key, "interface") == 0) {
+			r = pingu_conf_read_iface(f, chomp_bracket(value), &lineno);
+			if (r < 0)
+				break;
+		} else if (strcmp(key, "host") == 0) {
+			r = pingu_conf_read_host(f, chomp_bracket(value), &lineno);
+			if (r < 0)
+				break;
+		} else if (strcmp(key, "interval") == 0) {
+			default_burst_interval = atof(value);
+		} else if (strcmp(key, "retry") == 0) {
+			default_max_retries = atoi(value);
+		} else if (strcmp(key, "required") == 0) {
+			default_required_replies = atoi(value);
+		} else if (strcmp(key, "timeout") == 0) {
+			default_timeout = atof(value);
+		} else if (strcmp(key, "up-action") == 0) {
+			default_up_action = xstrdup(value);
+		} else if (strcmp(key, "down-action") == 0) {
+			default_down_action = xstrdup(value);
+		} else {
+			log_error("Unknown keyword '%s' on line %i", key,
+				  lineno);
+			r = -1;
+			break;
+		}
+	}
+	return r;
+}