add const to find_field

(Logical change 1.102)

misc/lnstat.h

+#ifndef _LNSTAT_H
+#define _LNSTAT_H
+
+#include <limits.h>
+
+#define LNSTAT_VERSION "0.02 041002"
+
+#define PROC_NET_STAT	"/proc/net/stat"
+
+#define LNSTAT_MAX_FILES			32
+#define LNSTAT_MAX_FIELDS_PER_LINE		32
+#define LNSTAT_MAX_FIELD_NAME_LEN		32
+
+struct lnstat_file;
+
+struct lnstat_field {
+	struct lnstat_file *file;
+	unsigned int num;			/* field number in line */
+	char name[LNSTAT_MAX_FIELD_NAME_LEN+1];
+	unsigned long values[2];		/* two buffers for values */
+	unsigned long result;
+};
+
+struct lnstat_file {
+	struct lnstat_file *next;
+	char path[PATH_MAX+1];
+	char basename[NAME_MAX+1];
+	struct timeval last_read;		/* last time of read */
+	struct timeval interval;		/* interval */
+	int compat;				/* 1 == backwards compat mode */
+	FILE *fp;
+	unsigned int num_fields;		/* number of fields */
+	struct lnstat_field fields[LNSTAT_MAX_FIELDS_PER_LINE];
+};
+
+
+struct lnstat_file *lnstat_scan_dir(const char *path, const int num_req_files,
+				    const char **req_files);
+int lnstat_update(struct lnstat_file *lnstat_files);
+int lnstat_dump(FILE *outfd, struct lnstat_file *lnstat_files);
+struct lnstat_field *lnstat_find_field(struct lnstat_file *lnstat_files,
+				       const char *name);
+#endif /* _LNSTAT_H */

misc/lnstat_util.c

+/* lnstat.c:  Unified linux network statistics
+ *
+ * Copyright (C) 2004 by Harald Welte <laforge@gnumonks.org>
+ *
+ * Development of this code was funded by Astaro AG, http://www.astaro.com/
+ *
+ * Based on original concept and ideas from predecessor rtstat.c:
+ *
+ * Copyright 2001 by Robert Olsson <robert.olsson@its.uu.se>
+ *                                 Uppsala University, Sweden
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <dirent.h>
+#include <limits.h>
+#include <time.h>
+
+#include <sys/time.h>
+#include <sys/types.h>
+
+#include "lnstat.h"
+
+/* size of temp buffer used to read lines from procfiles */
+#define FGETS_BUF_SIZE 1024
+
+
+#define RTSTAT_COMPAT_LINE "entries  in_hit in_slow_tot in_no_route in_brd in_martian_dst in_martian_src  out_hit out_slow_tot out_slow_mc  gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n"
+
+/* Read (and summarize for SMP) the different stats vars. */
+static int scan_lines(struct lnstat_file *lf, int i)
+{
+	int j, num_lines = 0;
+
+	for (j = 0; j < lf->num_fields; j++)
+		lf->fields[j].values[i] = 0;
+
+	while(!feof(lf->fp)) {
+		char buf[FGETS_BUF_SIZE];
+		char *ptr = buf;
+
+		num_lines++;
+
+		fgets(buf, sizeof(buf)-1, lf->fp); 
+		gettimeofday(&lf->last_read, NULL);
+
+		for (j = 0; j < lf->num_fields; j++)
+			lf->fields[j].values[i] = strtoul(ptr, &ptr, 16);
+	}
+	return num_lines;
+}
+
+static int time_after(struct timeval *last, 
+		      struct timeval *tout, 
+		      struct timeval *now)
+{
+	if (now->tv_sec > last->tv_sec + tout->tv_sec)
+		return 1;
+
+	if (now->tv_sec == last->tv_sec + tout->tv_sec) {
+		if (now->tv_usec > last->tv_usec + tout->tv_usec)
+			return 1;
+	}
+
+	return 0;
+}
+
+int lnstat_update(struct lnstat_file *lnstat_files)
+{
+	struct lnstat_file *lf;
+	char buf[FGETS_BUF_SIZE];
+	struct timeval tv;
+
+	gettimeofday(&tv, NULL);
+
+	for (lf = lnstat_files; lf; lf = lf->next) {
+		if (time_after(&lf->last_read, &lf->interval, &tv)) {
+			int i;
+			struct lnstat_field *lfi;
+
+			rewind(lf->fp);
+			if (!lf->compat) {
+				/* skip first line */
+				fgets(buf, sizeof(buf)-1, lf->fp);
+			}
+			scan_lines(lf, 1);
+
+			for (i = 0, lfi = &lf->fields[i]; 
+			     i < lf->num_fields; i++, lfi = &lf->fields[i]) {
+				if (i == 0)
+					lfi->result = lfi->values[1];
+				else
+					lfi->result = (lfi->values[1]-lfi->values[0])
+				    			/ lf->interval.tv_sec;
+			}
+
+			rewind(lf->fp);
+			fgets(buf, sizeof(buf)-1, lf->fp);
+			scan_lines(lf, 0);
+		}
+	}
+
+	return 0;
+}
+
+/* scan first template line and fill in per-field data structures */
+static int __lnstat_scan_fields(struct lnstat_file *lf, char *buf)
+{
+	char *tok;
+	int i;
+
+	tok = strtok(buf, " \t\n");
+	for (i = 0; i < LNSTAT_MAX_FIELDS_PER_LINE; i++) {
+		lf->fields[i].file = lf;
+		strncpy(lf->fields[i].name, tok, LNSTAT_MAX_FIELD_NAME_LEN);
+		/* has to be null-terminate since we initialize to zero
+		 * and field size is NAME_LEN + 1 */
+		tok = strtok(NULL, " \t\n");
+		if (!tok) {
+			lf->num_fields = i+1;
+			return 0;
+		}
+	}
+	return 0;
+}
+
+static int lnstat_scan_fields(struct lnstat_file *lf)
+{
+	char buf[FGETS_BUF_SIZE];
+
+	rewind(lf->fp);
+	fgets(buf, sizeof(buf)-1, lf->fp);
+
+	return __lnstat_scan_fields(lf, buf);
+}
+
+/* fake function emulating lnstat_scan_fields() for old kernels */
+static int lnstat_scan_compat_rtstat_fields(struct lnstat_file *lf)
+{
+	char buf[FGETS_BUF_SIZE];
+
+	strncpy(buf, RTSTAT_COMPAT_LINE, sizeof(buf)-1);
+
+	return __lnstat_scan_fields(lf, buf);
+}
+
+/* find out whether string 'name; is in given string array */
+static int name_in_array(const int num, const char **arr, const char *name)
+{
+	int i;
+	for (i = 0; i < num; i++) {
+		if (!strcmp(arr[i], name))
+			return 1;
+	}
+	return 0;
+}
+
+/* allocate lnstat_file and open given file */
+static struct lnstat_file *alloc_and_open(const char *path, const char *file)
+{
+	struct lnstat_file *lf;
+
+	/* allocate */
+	lf = malloc(sizeof(*lf));
+	if (!lf)
+		return NULL;
+
+	/* initialize */
+	memset(lf, 0, sizeof(*lf));
+
+	/* de->d_name is guaranteed to be <= NAME_MAX */
+	strcpy(lf->basename, file);
+	strcpy(lf->path, path);
+	strcat(lf->path, "/");
+	strcat(lf->path, lf->basename);
+
+	/* initialize to default */
+	lf->interval.tv_sec = 1;
+
+	/* open */
+	lf->fp = fopen(lf->path, "r");
+	if (!lf->fp) {
+		free(lf);
+		return NULL;
+	}
+
+	return lf;
+}
+
+
+/* lnstat_scan_dir - find and parse all available statistics files/fields */
+struct lnstat_file *lnstat_scan_dir(const char *path, const int num_req_files,
+				    const char **req_files)
+{
+	DIR *dir;
+	struct lnstat_file *lnstat_files = NULL;
+	struct dirent *de;
+
+	if (!path)
+		path = PROC_NET_STAT;
+	
+	dir = opendir(path);
+	if (!dir) {
+		struct lnstat_file *lf;
+		/* Old kernel, before /proc/net/stat was introduced */
+		fprintf(stderr, "Your kernel doesn't have lnstat support. ");
+
+		/* we only support rtstat, not multiple files */
+		if (num_req_files >= 2) {
+			fputc('\n', stderr);
+			return NULL;
+		}
+
+		/* we really only accept rt_cache */
+		if (num_req_files && !name_in_array(num_req_files,
+						    req_files, "rt_cache")) {
+			fputc('\n', stderr);
+			return NULL;
+		}
+
+		fprintf(stderr, "Fallback to old rtstat-only operation\n");
+
+		lf = alloc_and_open("/proc/net", "rt_cache_stat");
+		if (!lf)
+			return NULL;
+		lf->compat = 1;
+		strncpy(lf->basename, "rt_cache", sizeof(lf->basename));
+
+		/* FIXME: support for old files */
+		if (lnstat_scan_compat_rtstat_fields(lf) < 0)
+			return NULL;
+
+		lf->next = lnstat_files;
+		lnstat_files = lf;
+		return lnstat_files;
+	}
+
+	while ((de = readdir(dir))) {
+		struct lnstat_file *lf;
+
+		if (de->d_type != DT_REG)
+			continue;
+
+		if (num_req_files && !name_in_array(num_req_files,
+						    req_files, de->d_name))
+			continue;
+
+		lf = alloc_and_open(path, de->d_name);
+		if (!lf)
+			return NULL;
+
+		/* fill in field structure */
+		if (lnstat_scan_fields(lf) < 0)
+			return NULL;
+
+		/* prepend to global list */
+		lf->next = lnstat_files;
+		lnstat_files = lf;
+	}
+	closedir(dir);
+
+	return lnstat_files;
+}
+
+int lnstat_dump(FILE *outfd, struct lnstat_file *lnstat_files)
+{
+	struct lnstat_file *lf;
+
+	for (lf = lnstat_files; lf; lf = lf->next) {
+		int i;
+
+		fprintf(outfd, "%s:\n", lf->path);
+
+		for (i = 0; i < lf->num_fields; i++)
+			fprintf(outfd, "\t%2u: %s\n", i+1, lf->fields[i].name);
+
+	}
+	return 0;
+}
+
+struct lnstat_field *lnstat_find_field(struct lnstat_file *lnstat_files,
+				       const char *name)
+{
+	struct lnstat_file *lf;
+	struct lnstat_field *ret = NULL;
+	const char *colon = strchr(name, ':');
+	char *file;
+	const char *field;
+
+	if (colon) {
+		file = strndup(name, colon-name);
+		field = colon+1;
+	} else {
+		file = NULL;
+		field = name;
+	}
+		
+	for (lf = lnstat_files; lf; lf = lf->next) {
+		int i;
+
+		if (file && strcmp(file, lf->basename))
+			continue;
+
+		for (i = 0; i < lf->num_fields; i++) {
+			if (!strcmp(field, lf->fields[i].name)) {
+				ret = &lf->fields[i];
+				goto out;
+			}
+		}
+	}
+out:
+	if (file)
+		free(file);
+
+	return ret;
+}