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         int j, num_lines = 0;
  42
  43         for (j = 0; j < lf->num_fields; j++)
  44                 lf->fields[j].values[i] = 0;
  45
  46         while(!feof(lf->fp)) {
  47                 char buf[FGETS_BUF_SIZE];
  48                 char *ptr = buf;
  49
  50                 num_lines++;
  51
  52                 fgets(buf, sizeof(buf)-1, lf->fp);
  53                 gettimeofday(&lf->last_read, NULL);
  54
  55                 for (j = 0; j < lf->num_fields; j++) {
  56                         unsigned long f = strtoul(ptr, &ptr, 16);
  57                         if (j == 0)
  58                                 lf->fields[j].values[i] = f;
  59                         else
  60                                 lf->fields[j].values[i] += f;
  61                 }
  62         }
  63         return num_lines;
  64 }
  65
  66 static int time_after(struct timeval *last,
  67                       struct timeval *tout,
  68                       struct timeval *now)
  69 {
  70         if (now->tv_sec > last->tv_sec + tout->tv_sec)
  71                 return 1;
  72
  73         if (now->tv_sec == last->tv_sec + tout->tv_sec) {
  74                 if (now->tv_usec > last->tv_usec + tout->tv_usec)
  75                         return 1;
  76         }
  77
  78         return 0;
  79 }
  80
  81 int lnstat_update(struct lnstat_file *lnstat_files)
  82 {
  83         struct lnstat_file *lf;
  84         char buf[FGETS_BUF_SIZE];
  85         struct timeval tv;
  86
  87         gettimeofday(&tv, NULL);
  88
  89         for (lf = lnstat_files; lf; lf = lf->next) {
  90                 if (time_after(&lf->last_read, &lf->interval, &tv)) {
  91                         int i;
  92                         struct lnstat_field *lfi;
  93
  94                         rewind(lf->fp);
  95                         if (!lf->compat) {
  96                                 /* skip first line */
  97                                 fgets(buf, sizeof(buf)-1, lf->fp);
  98                         }
  99                         scan_lines(lf, 1);
 100
 101                         for (i = 0, lfi = &lf->fields[i];
 102                              i < lf->num_fields; i++, lfi = &lf->fields[i]) {
 103                                 if (i == 0)
 104                                         lfi->result = lfi->values[1];
 105                                 else
 106                                         lfi->result = (lfi->values[1]-lfi->values[0])
 107                                                         / lf->interval.tv_sec;
 108                         }
 109
 110                         rewind(lf->fp);
 111                         fgets(buf, sizeof(buf)-1, lf->fp);
 112                         scan_lines(lf, 0);
 113                 }
 114         }
 115
 116         return 0;
 117 }
 118
 119 /* scan first template line and fill in per-field data structures */
 120 static int __lnstat_scan_fields(struct lnstat_file *lf, char *buf)
 121 {
 122         char *tok;
 123         int i;
 124
 125         tok = strtok(buf, " \t\n");
 126         for (i = 0; i < LNSTAT_MAX_FIELDS_PER_LINE; i++) {
 127                 lf->fields[i].file = lf;
 128                 strncpy(lf->fields[i].name, tok, LNSTAT_MAX_FIELD_NAME_LEN);
 129                 /* has to be null-terminate since we initialize to zero
 130                  * and field size is NAME_LEN + 1 */
 131                 tok = strtok(NULL, " \t\n");
 132                 if (!tok) {
 133                         lf->num_fields = i+1;
 134                         return 0;
 135                 }
 136         }
 137         return 0;
 138 }
 139
 140 static int lnstat_scan_fields(struct lnstat_file *lf)
 141 {
 142         char buf[FGETS_BUF_SIZE];
 143
 144         rewind(lf->fp);
 145         fgets(buf, sizeof(buf)-1, lf->fp);
 146
 147         return __lnstat_scan_fields(lf, buf);
 148 }
 149
 150 /* fake function emulating lnstat_scan_fields() for old kernels */
 151 static int lnstat_scan_compat_rtstat_fields(struct lnstat_file *lf)
 152 {
 153         char buf[FGETS_BUF_SIZE];
 154
 155         strncpy(buf, RTSTAT_COMPAT_LINE, sizeof(buf)-1);
 156
 157         return __lnstat_scan_fields(lf, buf);
 158 }
 159
 160 /* find out whether string 'name; is in given string array */
 161 static int name_in_array(const int num, const char **arr, const char *name)
 162 {
 163         int i;
 164         for (i = 0; i < num; i++) {
 165                 if (!strcmp(arr[i], name))
 166                         return 1;
 167         }
 168         return 0;
 169 }
 170
 171 /* allocate lnstat_file and open given file */
 172 static struct lnstat_file *alloc_and_open(const char *path, const char *file)
 173 {
 174         struct lnstat_file *lf;
 175
 176         /* allocate */
 177         lf = malloc(sizeof(*lf));
 178         if (!lf)
 179                 return NULL;
 180
 181         /* initialize */
 182         memset(lf, 0, sizeof(*lf));
 183
 184         /* de->d_name is guaranteed to be <= NAME_MAX */
 185         strcpy(lf->basename, file);
 186         strcpy(lf->path, path);
 187         strcat(lf->path, "/");
 188         strcat(lf->path, lf->basename);
 189
 190         /* initialize to default */
 191         lf->interval.tv_sec = 1;
 192
 193         /* open */
 194         lf->fp = fopen(lf->path, "r");
 195         if (!lf->fp) {
 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                         return NULL;
 264
 265                 /* fill in field structure */
 266                 if (lnstat_scan_fields(lf) < 0)
 267                         return NULL;
 268
 269                 /* prepend to global list */
 270                 lf->next = lnstat_files;
 271                 lnstat_files = lf;
 272         }
 273         closedir(dir);
 274
 275         return lnstat_files;
 276 }
 277
 278 int lnstat_dump(FILE *outfd, struct lnstat_file *lnstat_files)
 279 {
 280         struct lnstat_file *lf;
 281
 282         for (lf = lnstat_files; lf; lf = lf->next) {
 283                 int i;
 284
 285                 fprintf(outfd, "%s:\n", lf->path);
 286
 287                 for (i = 0; i < lf->num_fields; i++)
 288                         fprintf(outfd, "\t%2u: %s\n", i+1, lf->fields[i].name);
 289
 290         }
 291         return 0;
 292 }
 293
 294 struct lnstat_field *lnstat_find_field(struct lnstat_file *lnstat_files,
 295                                        const char *name)
 296 {
 297         struct lnstat_file *lf;
 298         struct lnstat_field *ret = NULL;
 299         const char *colon = strchr(name, ':');
 300         char *file;
 301         const char *field;
 302
 303         if (colon) {
 304                 file = strndup(name, colon-name);
 305                 field = colon+1;
 306         } else {
 307                 file = NULL;
 308                 field = name;
 309         }
 310
 311         for (lf = lnstat_files; lf; lf = lf->next) {
 312                 int i;
 313
 314                 if (file && strcmp(file, lf->basename))
 315                         continue;
 316
 317                 for (i = 0; i < lf->num_fields; i++) {
 318                         if (!strcmp(field, lf->fields[i].name)) {
 319                                 ret = &lf->fields[i];
 320                                 goto out;
 321                         }
 322                 }
 323         }
 324 out:
 325         if (file)
 326                 free(file);
 327
 328         return ret;
 329 }