added if_err_ plugin

tools/munin-plugins-busybox/Makefile

@@ -1,9 +1,9 @@
 CC=gcc
 CFLAGS=-W -Wall -pedantic -Wextra -g -O2
-OBJS=main.o common.o cpu.o entropy.o forks.o fw_packets.o interrupts.o load.o \
+OBJS=main.o common.o cpu.o entropy.o forks.o fw_packets.o interrupts.o \
-     open_files.o open_inodes.o processes.o swap.o uptime.o
+     if_err_.o load.o open_files.o open_inodes.o processes.o swap.o uptime.o
-LINKS=cpu entropy forks fw_packets interrupts load open_files open_inodes \
+LINKS=cpu entropy forks fw_packets interrupts if_err_eth0 load open_files \
-      processes swap uptime
+      open_inodes processes swap uptime
 
 %.o:%.c
 	${CC} ${CFLAGS} -c $< -o $@

tools/munin-plugins-busybox/if_err_.c

@@ -0,0 +1,123 @@
+#include <ctype.h>
+#include <libgen.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#define PROC_NET_DEV "/proc/net/dev"
+
+int if_err_(int argc, char **argv) {
+	char *interface;
+	FILE *f;
+	char buff[256], *s;
+	int i;
+
+	interface = basename(argv[0]);
+	if(strncmp(interface, "if_err_", 7) != 0) {
+		fputs("if_err_ invoked with invalid basename\n", stderr);
+		return 1;
+	}
+	interface += 7;
+
+	if(argc > 1) {
+		if(!strcmp(argv[1], "autoconf")) {
+			if(access(PROC_NET_DEV, R_OK) == 0) {
+				puts("yes");
+				return 0;
+			} else {
+				puts("no (/proc/net/dev not found)");
+				return 1;
+			}
+		}
+		if(!strcmp(argv[1], "suggest")) {
+			if(NULL == (f = fopen(PROC_NET_DEV, "r")))
+				return 1;
+			while(fgets(buff, 256, f)) {
+				for(s=buff;*s == ' ';++s)
+					;
+				i = 0;
+				if(!strncmp(s, "eth", 3))
+					i = 3;
+				else if(!strncmp(s, "wlan", 4))
+					i = 4;
+				else if(!strncmp(s, "ath", 3))
+					i = 3;
+				else if(!strncmp(s, "ra", 2))
+					i = 2;
+				if(i == 0)
+					continue;
+				while(isdigit(s[i]))
+					++i;
+				if(s[i] != ':')
+					continue;
+				s[i] = '\0';
+				puts(s);
+			}
+			fclose(f);
+			return 0;
+		}
+		if(!strcmp(argv[1], "config")) {
+			puts("graph_order rcvd trans");
+			printf("graph_title %s errors\n", interface);
+			puts("graph_args --base 1000\n"
+				"graph_vlabel packets in (-) / out (+) per "
+					"${graph_period}\n"
+				"graph_category network");
+			printf("graph_info This graph shows the amount of "
+				"errors on the %s network interface.\n",
+				interface);
+			puts("rcvd.label packets\n"
+				"rcvd.type COUNTER\n"
+				"rcvd.graph no\n"
+				"rcvd.warning 1\n"
+				"trans.label packets\n"
+				"trans.type COUNTER\n"
+				"trans.negative rcvd\n"
+				"trans.warning 1");
+			return 0;
+		}
+	}
+	if(NULL == (f = fopen(PROC_NET_DEV, "r")))
+		return 1;
+	while(fgets(buff, 256, f)) {
+		for(s=buff;*s == ' ';++s)
+			;
+		if(0 != strncmp(s, interface, strlen(interface)))
+			continue;
+		s += strlen(interface);
+		if(*s != ':')
+			continue;
+		++s;
+
+		while(*s == ' ')
+			++s;
+
+		for(i=1;i<3;++i) {
+			while(isdigit(*s))
+				++s;
+			while(isspace(*s))
+				++s;
+		}
+		for(i=0;isdigit(s[i]);++i)
+			;
+		printf("rcvd.value ");
+		fwrite(s, 1, i, stdout);
+		putchar('\n');
+		s += i;
+		while(isspace(*s))
+			++s;
+
+		for(i=4;i<11;++i) {
+			while(isdigit(*s))
+				++s;
+			while(isspace(*s))
+				++s;
+		}
+		for(i=0;isdigit(s[i]);++i)
+			;
+		printf("trans.value ");
+		fwrite(s, 1, i, stdout);
+		putchar('\n');
+	}
+	return 0;
+}

tools/munin-plugins-busybox/main.c

@@ -6,6 +6,7 @@ int cpu(int argc, char **argv);
 int entropy(int argc, char **argv);
 int forks(int argc, char **argv);
 int fw_packets(int argc, char **argv);
+int if_err_(int argc, char **argv);
 int interrupts(int argc, char **argv);
 int load(int argc, char **argv);
 int open_files(int argc, char **argv);
@@ -35,6 +36,8 @@ int main(int argc, char **argv) {
 		case 'i':
 			if(!strcmp(progname+1, "nterrupts"))
 				return interrupts(argc, argv);
+			if(!strncmp(progname+1, "f_err_", 6))
+				return if_err_(argc, argv);
 			break;
 		case 'l':
 			if(!strcmp(progname+1, "oad"))