misc/lnstat_util.c

   1 /* lnstat.c:  Unified linux network statistics
   2  *
   3  * Copyright (C) 2004 by Harald Welte <laforge@gnumonks.org>
   4  *
   5  * Development of this code was funded by Astaro AG, http://www.astaro.com/
   6  *
   7  * Based on original concept and ideas from predecessor rtstat.c:
   8  *
   9  * Copyright 2001 by Robert Olsson <robert.olsson@its.uu.se>
  10  *                                 Uppsala University, Sweden
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  */
  18
  19 #include <unistd.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <dirent.h>
  24 #include <limits.h>
  25 #include <time.h>
  26
  27 #include <sys/time.h>
  28 #include <sys/types.h>
  29
  30 #include "lnstat.h"
  31
  32 /* size of temp buffer used to read lines from procfiles */
  33 #define FGETS_BUF_SIZE 1024
  34
  35
  36 #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"
  37
  38 /* Read (and summarize for SMP) the different stats vars. */
  39 static int scan_lines(struct lnstat_file *lf, int i)
  40 {
  41         char buf[FGETS_BUF_SIZE];
  42         int j, num_lines = 0;
  43
  44         for (j = 0; j < lf->num_fields; j++)
  45                 lf->fields[j].values[i] = 0;
  46
  47         rewind(lf->fp);
  48         /* skip first line */
  49         if (!lf->compat && !fgets(buf, sizeof(buf)-1, lf->fp))
  50                 return -1;
  51
  52         while(!feof(lf->fp) && fgets(buf, sizeof(buf)-1, lf->fp)) {
  53                 char *ptr = buf;
  54
  55                 num_lines++;
  56
  57                 gettimeofday(&lf->last_read, NULL);
  58
  59                 for (j = 0; j < lf->num_fields; j++) {
  60                         unsigned long f = strtoul(ptr, &ptr, 16);
  61                         if (j == 0)
  62                                 lf->fields[j].values[i] = f;
  63                         else
  64                                 lf->fields[j].values[i] += f;
  65                 }
  66         }
  67         return num_lines;
  68 }
  69
  70 static int time_after(struct timeval *last,
  71                       struct timeval *tout,
  72                       struct timeval *now)
  73 {
  74         if (now->tv_sec > last->tv_sec + tout->tv_sec)
  75                 return 1;
  76
  77         if (now->tv_sec == last->tv_sec + tout->tv_sec) {
  78                 if (now->tv_usec > last->tv_usec + tout->tv_usec)
  79                         return 1;
  80         }
  81
  82         return 0;
  83 }
  84
  85 int lnstat_update(struct lnstat_file *lnstat_files)
  86 {
  87         struct lnstat_file *lf;
  88         struct timeval tv;
  89
  90         gettimeofday(&tv, NULL);
  91
  92         for (lf = lnstat_files; lf; lf = lf->next) {
  93                 if (time_after(&lf->last_read, &lf->interval, &tv)) {
  94                         int i;
  95                         struct lnstat_field *lfi;
  96
  97                         scan_lines(lf, 1);
  98
  99                         for (i = 0, lfi = &lf->fields[i];
 100                              i < lf->num_fields; i++, lfi = &lf->fields[i]) {
 101                                 if (i == 0)
 102                                         lfi->result = lfi->values[1];
 103                                 else
 104                                         lfi->result = (lfi->values[1]-lfi->values[0])
 105                                                         / lf->interval.tv_sec;
 106                         }
 107
 108                         scan_lines(lf, 0);
 109                 }
 110         }
 111
 112         return 0;
 113 }
 114
 115 /* scan first template line and fill in per-field data structures */
 116 static int __lnstat_scan_fields(struct lnstat_file *lf, char *buf)
 117 {
 118         char *tok;
 119         int i;
 120
 121         tok = strtok(buf, " \t\n");
 122         for (i = 0; i < LNSTAT_MAX_FIELDS_PER_LINE; i++) {
 123                 lf->fields[i].file = lf;
 124                 strncpy(lf->fields[i].name, tok, LNSTAT_MAX_FIELD_NAME_LEN);
 125                 /* has to be null-terminate since we initialize to zero
 126                  * and field size is NAME_LEN + 1 */
 127                 tok = strtok(NULL, " \t\n");
 128                 if (!tok) {
 129                         lf->num_fields = i+1;
 130                         return 0;
 131                 }
 132         }
 133         return 0;
 134 }
 135
 136 static int lnstat_scan_fields(struct lnstat_file *lf)
 137 {
 138         char buf[FGETS_BUF_SIZE];
 139
 140         rewind(lf->fp);
 141         if (!fgets(buf, sizeof(buf)-1, lf->fp))
 142                 return -1;
 143
 144         return __lnstat_scan_fields(lf, buf);
 145 }
 146
 147 /* fake function emulating lnstat_scan_fields() for old kernels */
 148 static int lnstat_scan_compat_rtstat_fields(struct lnstat_file *lf)
 149 {
 150         char buf[FGETS_BUF_SIZE];
 151
 152         strncpy(buf, RTSTAT_COMPAT_LINE, sizeof(buf)-1);
 153
 154         return __lnstat_scan_fields(lf, buf);
 155 }
 156
 157 /* find out whether string 'name; is in given string array */
 158 static int name_in_array(const int num, const char **arr, const char *name)
 159 {
 160         int i;
 161         for (i = 0; i < num; i++) {
 162                 if (!strcmp(arr[i], name))
 163                         return 1;
 164         }
 165         return 0;
 166 }
 167
 168 /* allocate lnstat_file and open given file */
 169 static struct lnstat_file *alloc_and_open(const char *path, const char *file)
 170 {
 171         struct lnstat_file *lf;
 172
 173         /* allocate */
 174         lf = malloc(sizeof(*lf));
 175         if (!lf)
 176                 return NULL;
 177
 178         /* initialize */
 179         memset(lf, 0, sizeof(*lf));
 180
 181         /* de->d_name is guaranteed to be <= NAME_MAX */
 182         strcpy(lf->basename, file);
 183         strcpy(lf->path, path);
 184         strcat(lf->path, "/");
 185         strcat(lf->path, lf->basename);
 186
 187         /* initialize to default */
 188         lf->interval.tv_sec = 1;
 189
 190         /* open */
 191         lf->fp = fopen(lf->path, "r");
 192         if (!lf->fp) {
 193                 free(lf);
 194                 return NULL;
 195         }
 196
 197         return lf;
 198 }
 199
 200
 201 /* lnstat_scan_dir - find and parse all available statistics files/fields */
 202 struct lnstat_file *lnstat_scan_dir(const char *path, const int num_req_files,
 203                                     const char **req_files)
 204 {
 205         DIR *dir;
 206         struct lnstat_file *lnstat_files = NULL;
 207         struct dirent *de;
 208
 209         if (!path)
 210                 path = PROC_NET_STAT;
 211
 212         dir = opendir(path);
 213         if (!dir) {
 214                 struct lnstat_file *lf;
 215                 /* Old kernel, before /proc/net/stat was introduced */
 216                 fprintf(stderr, "Your kernel doesn't have lnstat support. ");
 217
 218                 /* we only support rtstat, not multiple files */
 219                 if (num_req_files >= 2) {
 220                         fputc('\n', stderr);
 221                         return NULL;
 222                 }
 223
 224                 /* we really only accept rt_cache */
 225                 if (num_req_files && !name_in_array(num_req_files,
 226                                                     req_files, "rt_cache")) {
 227                         fputc('\n', stderr);
 228                         return NULL;
 229                 }
 230
 231                 fprintf(stderr, "Fallback to old rtstat-only operation\n");
 232
 233                 lf = alloc_and_open("/proc/net", "rt_cache_stat");
 234                 if (!lf)
 235                         return NULL;
 236                 lf->compat = 1;
 237                 strncpy(lf->basename, "rt_cache", sizeof(lf->basename));
 238
 239                 /* FIXME: support for old files */
 240                 if (lnstat_scan_compat_rtstat_fields(lf) < 0)
 241                         return NULL;
 242
 243                 lf->next = lnstat_files;
 244                 lnstat_files = lf;
 245                 return lnstat_files;
 246         }
 247
 248         while ((de = readdir(dir))) {
 249                 struct lnstat_file *lf;
 250
 251                 if (de->d_type != DT_REG)
 252                         continue;
 253
 254                 if (num_req_files && !name_in_array(num_req_files,
 255                                                     req_files, de->d_name))
 256                         continue;
 257
 258                 lf = alloc_and_open(path, de->d_name);
 259                 if (!lf)
 260                         return NULL;
 261
 262                 /* fill in field structure */
 263                 if (lnstat_scan_fields(lf) < 0)
 264                         return NULL;
 265
 266                 /* prepend to global list */
 267                 lf->next = lnstat_files;
 268                 lnstat_files = lf;
 269         }
 270         closedir(dir);
 271
 272         return lnstat_files;
 273 }
 274
 275 int lnstat_dump(FILE *outfd, struct lnstat_file *lnstat_files)
 276 {
 277         struct lnstat_file *lf;
 278
 279         for (lf = lnstat_files; lf; lf = lf->next) {
 280                 int i;
 281
 282                 fprintf(outfd, "%s:\n", lf->path);
 283
 284                 for (i = 0; i < lf->num_fields; i++)
 285                         fprintf(outfd, "\t%2u: %s\n", i+1, lf->fields[i].name);
 286
 287         }
 288         return 0;
 289 }
 290
 291 struct lnstat_field *lnstat_find_field(struct lnstat_file *lnstat_files,
 292                                        const char *name)
 293 {
 294         struct lnstat_file *lf;
 295         struct lnstat_field *ret = NULL;
 296         const char *colon = strchr(name, ':');
 297         char *file;
 298         const char *field;
 299
 300         if (colon) {
 301                 file = strndup(name, colon-name);
 302                 field = colon+1;
 303         } else {
 304                 file = NULL;
 305                 field = name;
 306         }
 307
 308         for (lf = lnstat_files; lf; lf = lf->next) {
 309                 int i;
 310
 311                 if (file && strcmp(file, lf->basename))
 312                         continue;
 313
 314                 for (i = 0; i < lf->num_fields; i++) {
 315                         if (!strcmp(field, lf->fields[i].name)) {
 316                                 ret = &lf->fields[i];
 317                                 goto out;
 318                         }
 319                 }
 320         }
 321 out:
 322         free(file);
 323
 324         return ret;
 325 }