release/src/router/pptpd/configfile.c

   1 /*
   2  * configfile.c
   3  *
   4  * Methods for accessing the PPTPD config file and searching for
   5  * PPTPD keywords.
   6  *
   7  * $Id: configfile.c,v 1.2 2004/04/22 10:48:16 quozl Exp $
   8  */
   9
  10 #ifdef HAVE_CONFIG_H
  11 #include "config.h"
  12 #endif
  13
  14 #include <stdio.h>
  15 #include <string.h>
  16 #include <ctype.h>
  17
  18 #include "defaults.h"
  19 #include "configfile.h"
  20 #include "our_syslog.h"
  21
  22 /* Local function prototypes */
  23 static FILE *open_config_file(char *filename);
  24 static void close_config_file(FILE * file);
  25
  26 /*
  27  * read_config_file
  28  *
  29  * This method opens up the file specified by 'filename' and searches
  30  * through the file for 'keyword'. If 'keyword' is found any string
  31  * following it is stored in 'value'.
  32  *
  33  * args: filename (IN) - config filename
  34  *       keyword (IN) - word to search for in config file
  35  *       value (OUT) - value of keyword
  36  *
  37  * retn: -1 on error, 0 if keyword not found, 1 on value success
  38  */
  39 int read_config_file(char *filename, char *keyword, char *value)
  40 {
  41         FILE *in;
  42         int len = 0, keyword_len = 0;
  43         int foundit = 0;
  44
  45         char *buff_ptr;
  46         char buffer[MAX_CONFIG_STRING_SIZE];
  47
  48         *value = '\0';
  49         buff_ptr = buffer;
  50         keyword_len = strlen(keyword);
  51
  52         in = open_config_file(filename);
  53         if (in == NULL) {
  54                 /* Couldn't find config file, or permission denied */
  55                 return -1;
  56         }
  57         while ((fgets(buffer, MAX_CONFIG_STRING_SIZE - 1, in)) != NULL) {
  58                 /* ignore long lines */
  59                 if (buffer[(len = strlen(buffer)) - 1] != '\n') {
  60                         syslog(LOG_ERR, "Long config file line ignored.");
  61                         do
  62                                 fgets(buffer, MAX_CONFIG_STRING_SIZE - 1, in);
  63                         while (buffer[strlen(buffer) - 1] != '\n');
  64                         continue;
  65                 }
  66
  67                 len--;                  /* For the NL at the end */
  68                 while (--len >= 0)
  69                         if (buffer[len] != ' ' && buffer[len] != '\t')
  70                                 break;
  71
  72                 len++;
  73                 buffer[len] = '\0';
  74
  75                 buff_ptr = buffer;
  76
  77                 /* Short-circuit blank lines and comments */
  78                 if (!len || *buff_ptr == '#')
  79                         continue;
  80
  81                 /* Non-blank lines starting with a space are an error */
  82
  83                 if (*buff_ptr == ' ' || *buff_ptr == '\t') {
  84                         syslog(LOG_ERR, "Config file line starts with a space: %s", buff_ptr);
  85                         continue;
  86                 }
  87
  88                 /* At this point we have a line trimmed for trailing spaces. */
  89                 /* Now we need to check if the keyword matches, and if so */
  90                 /* then get the value (if any). */
  91
  92                 /* Check if it's the right keyword */
  93
  94                 do {
  95                         if (*buff_ptr == ' ' || *buff_ptr == '\t')
  96                                 break;
  97                 } while (*++buff_ptr);
  98
  99                 len = buff_ptr - buffer;
 100                 if (len == keyword_len && !strncmp(buffer, keyword, len)) {
 101                         foundit++;
 102                         break;
 103                 }
 104         }
 105
 106         close_config_file(in);
 107
 108         if (foundit) {
 109                 /* Right keyword, now get the value (if any) */
 110
 111                 do {
 112                         if (*buff_ptr != ' ' && *buff_ptr != '\t')
 113                                 break;
 114
 115                 } while (*++buff_ptr);
 116
 117                 strcpy(value, buff_ptr);
 118                 return 1;
 119         } else {
 120                 /* didn't find it - better luck next time */
 121                 return 0;
 122         }
 123 }
 124
 125 /*
 126  * open_config_file
 127  *
 128  * Opens up the PPTPD config file for reading.
 129  *
 130  * args: filename - the config filename (eg. '/etc/pptpd.conf')
 131  *
 132  * retn: NULL on error, file descriptor on success
 133  *
 134  */
 135 static FILE *open_config_file(char *filename)
 136 {
 137         FILE *in;
 138         static int first = 1;
 139
 140         if ((in = fopen(filename, "r")) == NULL) {
 141                 /* Couldn't open config file */
 142                 if (first) {
 143                         perror(filename);
 144                         first = 0;
 145                 }
 146                 return NULL;
 147         }
 148         return in;
 149 }
 150
 151 /*
 152  * close_config_file
 153  *
 154  * Closes the PPTPD config file descriptor
 155  *
 156  */
 157 static void close_config_file(FILE * in)
 158 {
 159         fclose(in);
 160 }