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
  62                         if (j == 0)
  63                                 lf->fields[j].values[i] = f;
  64                         else
  65                                 lf->fields[j].values[i] += f;
  66                 }
  67         }
  68         return num_lines;
  69 }
  70
  71 static int time_after(struct timeval *last,
  72                       struct timeval *tout,
  73                       struct timeval *now)
  74 {
  75         if (now->tv_sec > last->tv_sec + tout->tv_sec)
  76                 return 1;
  77
  78         if (now->tv_sec == last->tv_sec + tout->tv_sec) {
  79                 if (now->tv_usec > last->tv_usec + tout->tv_usec)
  80                         return 1;
  81         }
  82
  83         return 0;
  84 }
  85
  86 int lnstat_update(struct lnstat_file *lnstat_files)
  87 {
  88         struct lnstat_file *lf;
  89         struct timeval tv;
  90
  91         gettimeofday(&tv, NULL);
  92
  93         for (lf = lnstat_files; lf; lf = lf->next) {
  94                 if (time_after(&lf->last_read, &lf->interval, &tv)) {
  95                         int i;
  96                         struct lnstat_field *lfi;
  97
  98                         scan_lines(lf, 1);
  99
 100                         for (i = 0, lfi = &lf->fields[i];
 101                              i < lf->num_fields; i++, lfi = &lf->fields[i]) {
 102                                 if (i == 0)
 103                                         lfi->result = lfi->values[1];
 104                                 else
 105                                         lfi->result = (lfi->values[1]-lfi->values[0])
 106                                                         / lf->interval.tv_sec;
 107                         }
 108
 109                         scan_lines(lf, 0);
 110                 }
 111         }
 112
 113         return 0;
 114 }
 115
 116 /* scan first template line and fill in per-field data structures */
 117 static int __lnstat_scan_fields(struct lnstat_file *lf, char *buf)
 118 {
 119         char *tok;
 120         int i;
 121
 122         tok = strtok(buf, " \t\n");
 123         for (i = 0; i < LNSTAT_MAX_FIELDS_PER_LINE; i++) {
 124                 lf->fields[i].file = lf;
 125                 strncpy(lf->fields[i].name, tok, LNSTAT_MAX_FIELD_NAME_LEN);
 126                 /* has to be null-terminate since we initialize to zero
 127                  * and field size is NAME_LEN + 1 */
 128                 tok = strtok(NULL, " \t\n");
 129                 if (!tok) {
 130                         lf->num_fields = i+1;
 131                         return 0;
 132                 }
 133         }
 134         return 0;
 135 }
 136
 137 static int lnstat_scan_fields(struct lnstat_file *lf)
 138 {
 139         char buf[FGETS_BUF_SIZE];
 140
 141         rewind(lf->fp);
 142         if (!fgets(buf, sizeof(buf)-1, lf->fp))
 143                 return -1;
 144
 145         return __lnstat_scan_fields(lf, buf);
 146 }
 147
 148 /* fake function emulating lnstat_scan_fields() for old kernels */
 149 static int lnstat_scan_compat_rtstat_fields(struct lnstat_file *lf)
 150 {
 151         char buf[FGETS_BUF_SIZE];
 152
 153         strncpy(buf, RTSTAT_COMPAT_LINE, sizeof(buf)-1);
 154
 155         return __lnstat_scan_fields(lf, buf);
 156 }
 157
 158 /* find out whether string 'name; is in given string array */
 159 static int name_in_array(const int num, const char **arr, const char *name)
 160 {
 161         int i;
 162
 163         for (i = 0; i < num; i++) {
 164                 if (!strcmp(arr[i], name))
 165                         return 1;
 166         }
 167         return 0;
 168 }
 169
 170 /* allocate lnstat_file and open given file */
 171 static struct lnstat_file *alloc_and_open(const char *path, const char *file)
 172 {
 173         struct lnstat_file *lf;
 174
 175         /* allocate */
 176         lf = calloc(1, sizeof(*lf));
 177         if (!lf) {
 178                 fprintf(stderr, "out of memory\n");
 179                 return NULL;
 180         }
 181
 182         /* initialize */
 183         /* de->d_name is guaranteed to be <= NAME_MAX */
 184         strcpy(lf->basename, file);
 185         strcpy(lf->path, path);
 186         strcat(lf->path, "/");
 187         strcat(lf->path, lf->basename);
 188
 189         /* initialize to default */
 190         lf->interval.tv_sec = 1;
 191
 192         /* open */
 193         lf->fp = fopen(lf->path, "r");
 194         if (!lf->fp) {
 195                 perror(lf->path);
 196                 free(lf);
 197                 return NULL;
 198         }
 199
 200         return lf;
 201 }
 202
 203
 204 /* lnstat_scan_dir - find and parse all available statistics files/fields */
 205 struct lnstat_file *lnstat_scan_dir(const char *path, const int num_req_files,
 206                                     const char **req_files)
 207 {
 208         DIR *dir;
 209         struct lnstat_file *lnstat_files = NULL;
 210         struct dirent *de;
 211
 212         if (!path)
 213                 path = PROC_NET_STAT;
 214
 215         dir = opendir(path);
 216         if (!dir) {
 217                 struct lnstat_file *lf;
 218                 /* Old kernel, before /proc/net/stat was introduced */
 219                 fprintf(stderr, "Your kernel doesn't have lnstat support. ");
 220
 221                 /* we only support rtstat, not multiple files */
 222                 if (num_req_files >= 2) {
 223                         fputc('\n', stderr);
 224                         return NULL;
 225                 }
 226
 227                 /* we really only accept rt_cache */
 228                 if (num_req_files && !name_in_array(num_req_files,
 229                                                     req_files, "rt_cache")) {
 230                         fputc('\n', stderr);
 231                         return NULL;
 232                 }
 233
 234                 fprintf(stderr, "Fallback to old rtstat-only operation\n");
 235
 236                 lf = alloc_and_open("/proc/net", "rt_cache_stat");
 237                 if (!lf)
 238                         return NULL;
 239                 lf->compat = 1;
 240                 strncpy(lf->basename, "rt_cache", sizeof(lf->basename));
 241
 242                 /* FIXME: support for old files */
 243                 if (lnstat_scan_compat_rtstat_fields(lf) < 0)
 244                         return NULL;
 245
 246                 lf->next = lnstat_files;
 247                 lnstat_files = lf;
 248                 return lnstat_files;
 249         }
 250
 251         while ((de = readdir(dir))) {
 252                 struct lnstat_file *lf;
 253
 254                 if (de->d_type != DT_REG)
 255                         continue;
 256
 257                 if (num_req_files && !name_in_array(num_req_files,
 258                                                     req_files, de->d_name))
 259                         continue;
 260
 261                 lf = alloc_and_open(path, de->d_name);
 262                 if (!lf) {
 263                         closedir(dir);
 264                         return NULL;
 265                 }
 266
 267                 /* fill in field structure */
 268                 if (lnstat_scan_fields(lf) < 0) {
 269                         closedir(dir);
 270                         return NULL;
 271                 }
 272
 273                 /* prepend to global list */
 274                 lf->next = lnstat_files;
 275                 lnstat_files = lf;
 276         }
 277         closedir(dir);
 278
 279         return lnstat_files;
 280 }
 281
 282 int lnstat_dump(FILE *outfd, struct lnstat_file *lnstat_files)
 283 {
 284         struct lnstat_file *lf;
 285
 286         for (lf = lnstat_files; lf; lf = lf->next) {
 287                 int i;
 288
 289                 fprintf(outfd, "%s:\n", lf->path);
 290
 291                 for (i = 0; i < lf->num_fields; i++)
 292                         fprintf(outfd, "\t%2u: %s\n", i+1, lf->fields[i].name);
 293
 294         }
 295         return 0;
 296 }
 297
 298 struct lnstat_field *lnstat_find_field(struct lnstat_file *lnstat_files,
 299                                        const char *name)
 300 {
 301         struct lnstat_file *lf;
 302         struct lnstat_field *ret = NULL;
 303         const char *colon = strchr(name, ':');
 304         char *file;
 305         const char *field;
 306
 307         if (colon) {
 308                 file = strndup(name, colon-name);
 309                 field = colon+1;
 310         } else {
 311                 file = NULL;
 312                 field = name;
 313         }
 314
 315         for (lf = lnstat_files; lf; lf = lf->next) {
 316                 int i;
 317
 318                 if (file && strcmp(file, lf->basename))
 319                         continue;
 320
 321                 for (i = 0; i < lf->num_fields; i++) {
 322                         if (!strcmp(field, lf->fields[i].name)) {
 323                                 ret = &lf->fields[i];
 324                                 goto out;
 325                         }
 326                 }
 327         }
 328 out:
 329         free(file);
 330
 331         return ret;
 332 }