Merge pull request #20 from ifupdown-ng/ifctrstat

Add ifctrstat applet

.gitignore

@@ -12,4 +12,5 @@ ifupdown
 ifquery
 ifup
 ifdown
+ifctrstat
 *.lock

Makefile

@@ -62,6 +62,13 @@ MULTICALL_${CONFIG_IFQUERY}_OBJ += ${IFQUERY_SRC:.c=.o}
 CMDS_${CONFIG_IFQUERY} += ifquery
 CPPFLAGS_${CONFIG_IFQUERY} += -DCONFIG_IFQUERY
 
+# enable ifctrstat applet (+1 KB)
+CONFIG_IFCTRSTAT ?= Y
+IFCTRSTAT_SRC = cmd/ifctrstat.c cmd/ifctrstat-${LAYOUT}.c
+MULTICALL_${CONFIG_IFCTRSTAT}_OBJ += ${IFCTRSTAT_SRC:.c=.o}
+CMDS_${CONFIG_IFCTRSTAT} += ifctrstat
+CPPFLAGS_${CONFIG_IFCTRSTAT} += -DCONFIG_IFCTRSTAT
+
 MULTICALL_OBJ += ${MULTICALL_Y_OBJ}
 CMDS += ${CMDS_Y}
 CPPFLAGS += ${CPPFLAGS_Y}

cmd/ifctrstat-linux.c

@@ -0,0 +1,96 @@
+/*
+ * cmd/ifctrstat-linux.c
+ * Purpose: Implement ifctrstat system-specific routines for Linux
+ *
+ * Copyright (c) 2020 Adélie Software in the Public Benefit, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
+#include "multicall.h"
+
+struct counter_desc {
+	const char *name;
+	const void *data;
+} avail_counters[] = {
+	{"rx.discard", "rx_dropped"},
+	{"rx.errors", "rx_errors"},
+	{"rx.octets", "rx_bytes"},
+	{"rx.packets", "rx_packets"},
+	{"tx.discard", "tx_dropped"},
+	{"tx.errors", "tx_errors"},
+	{"tx.octets", "tx_bytes"},
+	{"tx.packets", "tx_packets"}
+};
+
+size_t avail_counters_count = ARRAY_SIZE(avail_counters);
+
+static int
+counter_compare(const void *key, const void *candidate)
+{
+	return strcasecmp((const char *)key, ((struct counter_desc *)candidate)->name);
+}
+
+char *
+read_counter(const char *interface, const char *counter)
+{
+	FILE *fp;
+	const char *path;
+	char full_path[PATH_MAX];
+	char buffer[1024];
+	size_t in_count;
+	struct counter_desc *ctrdata;
+
+	errno = 0;
+
+	ctrdata = bsearch(counter, avail_counters, avail_counters_count, sizeof(struct counter_desc), counter_compare);
+	if (ctrdata) {
+		path = (const char *)ctrdata->data;
+	} else {
+		errno = ENOSYS;
+		return NULL;
+	}
+
+	if (snprintf(full_path, PATH_MAX, "/sys/class/net/%s/statistics/%s", interface, path) > PATH_MAX)
+	{
+		errno = ENOMEM;
+		return NULL;
+	}
+
+	fp = fopen(full_path, "r");
+	if (!fp)
+	{
+		return NULL;
+	}
+
+	in_count = fread(buffer, 1, sizeof(buffer), fp);
+
+	if (in_count == sizeof(buffer))
+	{
+		errno = ENOMEM;
+		fclose(fp);
+		return NULL;
+	}
+
+	if (ferror(fp))
+	{
+		return NULL;
+	}
+
+	fclose(fp);
+
+	/* take away the \n, we add our own */
+	buffer[in_count - 1] = '\0';
+
+	return strdup(buffer);
+}

cmd/ifctrstat.c

@@ -0,0 +1,161 @@
+/*
+ * cmd/ifctrstat.c
+ * Purpose: Display statistics about interfaces on the system
+ *
+ * Copyright (c) 2020 Adélie Software in the Public Benefit, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#include <errno.h>
+#include <getopt.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include "libifupdown/libifupdown.h"
+#include "cmd/multicall.h"
+
+extern struct counter_desc { const char *name; const void *data; } avail_counters[];
+extern int avail_counters_count;
+
+extern const char *read_counter(const char *interface, const char *counter);
+
+static bool show_label = true;
+
+static bool
+counter_is_valid(const char *candidate)
+{
+	for (int i = 0; i < avail_counters_count; i++)
+	{
+		if (strcasecmp(avail_counters[i].name, candidate) == 0)
+			return true;
+	}
+
+	return false;
+}
+
+static void
+print_counter(const char *iface, const char *name, const char *value)
+{
+	if (show_label)
+		fprintf(stdout, "%s: %s\n", name, value);
+	else
+		fprintf(stdout, "%s\n", value);
+}
+
+static int
+print_all_counters(const char *iface)
+{
+	int code = EXIT_SUCCESS;
+	const char *res;
+
+	for (int i = 0; i < avail_counters_count; i++) {
+		const char *ctr = avail_counters[i].name;
+
+		res = read_counter(iface, ctr);
+		if (!res)
+		{
+			fprintf(stderr, "%s: could not determine value of %s for interface %s: %s\n", argv0, ctr, iface, strerror(errno));
+			code = EXIT_FAILURE;
+		} else {
+			print_counter(iface, ctr, res);
+		}
+	}
+
+	return code;
+}
+
+void
+ifctrstat_list_counters(int short_opt, const struct if_option *opt, const char *opt_arg, const struct if_applet *applet)
+{
+	(void) short_opt;
+	(void) opt;
+	(void) opt_arg;
+	(void) applet;
+
+	for (int i = 0; i < avail_counters_count; i++)
+	{
+		fprintf(stdout, "%s\n", avail_counters[i].name);
+	}
+
+	exit(EXIT_SUCCESS);
+}
+
+void
+ifctrstat_set_nolabel(int short_opt, const struct if_option *opt, const char *opt_arg, const struct if_applet *applet)
+{
+	(void) short_opt;
+	(void) opt;
+	(void) opt_arg;
+	(void) applet;
+
+	show_label = false;
+}
+
+int
+ifctrstat_main(int argc, char *argv[])
+{
+	if (optind >= argc)
+		generic_usage(self_applet, EXIT_FAILURE);
+
+	int idx = optind;
+	if (argc - idx == 0)
+	{
+		fprintf(stderr, "%s: interface required\n",
+			argv0);
+		return EXIT_FAILURE;
+	}
+
+	const char *iface = argv[idx++];
+
+	if (argc - idx == 0)
+	{
+		return print_all_counters(iface);
+	}
+
+	for (; idx < argc; idx++)
+	{
+		if (!counter_is_valid(argv[idx]))
+		{
+			fprintf(stderr, "%s: counter %s is not valid or not available\n", argv0, argv[idx]);
+			return EXIT_FAILURE;
+		}
+
+		errno = 0;
+		const char *res = read_counter(iface, argv[idx]);
+		if (!res)
+		{
+			fprintf(stderr, "%s: could not determine value of %s for interface %s: %s\n", argv0, argv[idx], iface, strerror(errno));
+			return EXIT_FAILURE;
+		}
+
+		print_counter(iface, argv[idx], res);
+	}
+
+	return EXIT_SUCCESS;
+}
+
+static struct if_option local_options[] = {
+	{'L', "list", NULL, "List available counters", false, ifctrstat_list_counters},
+	{'n', "no-label", NULL, "Print value without counter label", false, ifctrstat_set_nolabel}
+};
+
+static struct if_option_group local_option_group = {
+	.desc = "Program-specific options",
+	.group_size = ARRAY_SIZE(local_options),
+	.group = local_options
+};
+
+struct if_applet ifctrstat_applet = {
+	.name = "ifctrstat",
+	.desc = "Display statistics about an interface",
+	.main = ifctrstat_main,
+	.usage = "ifctrstat [options] <interface> <counter>\n  ifctrstat [options] --list\n",
+	.groups = { &global_option_group, &local_option_group, NULL }
+};

cmd/multicall.c

@@ -32,10 +32,17 @@ extern struct if_applet ifup_applet;
 extern struct if_applet ifdown_applet;
 #endif
 
+#ifdef CONFIG_IFCTRSTAT
+extern struct if_applet ifctrstat_applet;
+#endif
+
 struct if_applet ifupdown_applet;
 const struct if_applet *self_applet = NULL;
 
 struct if_applet *applet_table[] = {
+#ifdef CONFIG_IFCTRSTAT
+	&ifctrstat_applet,
+#endif
 #ifdef CONFIG_IFUPDOWN
 	&ifdown_applet,
 #endif