addconfigfile.c

Linux下对防火墙log的parsing。Linux下调试通过。附带有makefile可供编译。

#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <firewall.h>

/* adds one configuration to the list of already present configurations */
struct FirewallConfig *addEntry (struct ConfigEntry *entry, struct FirewallConfig *config) {
  
  struct FirewallConfig *newElement;

  newElement = malloc (sizeof (struct FirewallConfig));
  if (!newElement) {
    fprintf (stderr, "Out of memory!\n");
    exit (1);
  }
  
  newElement->entry = entry;
  newElement->next = config;
  return newElement;
}

/* copies lists and allocates memory in the process */
struct ElementList *elementListCopy (struct ElementList *list) {
     struct ElementList *head, *previous, *newElement;
     
     head = NULL;
     previous = NULL;


     while (list) {
       newElement = malloc (sizeof (struct ElementList));
       if (!newElement) {
	 fprintf (stderr, "Out of memory!\n");
	 exit (1);
       }

       newElement->element = strdup (list->element);
       newElement->next = NULL;
       
       if (head == NULL) {
	 head = newElement;
       }
       else {
	 if (previous) {
	   previous->next = newElement;
	 }
	 previous = newElement;
       }
       list = list->next;
     }
     
     return head;
}
	   
       

/* adds configurations arising from one line of the configuration file to the list of configurations. *line contains the data corresponding to one line. Returns NULL if parsing error occurred. */
struct FirewallConfig *addLine (struct ConfigLine *line, struct FirewallConfig *config, int *errno) {
  
  *errno = 0;
  char *tmp;
  int portno;
  struct ElementList *uids, *programs, *IPAddresses, *ports;
  struct ConfigEntry *entry;

  /* extract all configurations from the one line */
  uids = line->uids;
  programs = line->programs;
  IPAddresses = line->IPAddresses;
  ports = line->ports;
  while (ports) {
    if (strcmp (ports->element, "*") == 0) {
      portno = 0;
    }
    else {
      /* check whether we have valid port number */
      portno = strtol(ports->element, &tmp, 10);
    }
    if ((tmp  && strcmp (tmp, ""))|| (portno == 0)) {
      *errno = ILLEGAL_PORT;
      return NULL;
    }

    entry  = malloc (sizeof (struct ConfigEntry));
    if (!entry) {
      fprintf (stderr, "Out of memory!\n");
      exit (1);
    }
    
    entry->uids = elementListCopy (uids);
    entry->programs = elementListCopy (programs);
    entry->IPAddresses = elementListCopy (IPAddresses);
    entry->port = portno;
	  
    config = addEntry (entry, config);
	  
    ports = ports->next;
  }
  return config;
}

/* prints a list of uids etc */
void printStringList ( char *initialString, struct ElementList *list) {

  printf (initialString);
  while (list) {
    printf("%s", list->element);
    list = list->next;
  }
  printf ("\n");
}
    
/* sorts the list of configurations */
struct FirewallConfig *firewallTableSort (struct FirewallConfig *firewallTable) {
  int noOfElem;
  int i;
  struct FirewallConfig *tmp;

  /* how long is the list? */
  tmp = firewallTable;
  noOfElem = 0;
  while (tmp) {
    noOfElem++;
    tmp = tmp->next;
  }

  if (noOfElem <= 1) {
    /* nothing to be sorted */
    return firewallTable;
  }

  /* now create an araray of pointers for quicksort */
  struct FirewallConfig *sortingArray[noOfElem];
  tmp = firewallTable;  
  for (i = 0; i < noOfElem; i++) {
    sortingArray[i] = tmp;
    tmp = tmp->next;
  }

  /* sort this array */
  qsort (&sortingArray[0], noOfElem, sizeof (struct FirewallConfig *), compareEntry);

  /* now create a sorted list from the array */
  tmp = sortingArray[0];
  for (i = 1; i < noOfElem; i++) {
    tmp->next = sortingArray[i];
    tmp = tmp->next;
  }
  tmp->next = NULL;

  return (sortingArray[0]);
}

/* print out the list of configurations */
void printTable (struct FirewallConfig *firewallTable) {
  

  while (firewallTable) {
    
    printStringList ("uids = ", firewallTable->entry->uids);
    printStringList ("programs = ", firewallTable->entry->programs);
    printStringList ("IPAddress = ", firewallTable->entry->IPAddresses);
    printf ("port = %d\n\n", firewallTable->entry->port);
    
    firewallTable = firewallTable->next;
  }
}

int main (int argc, char **argv) {

  size_t len;
  char *line = NULL;
  int errno;

  struct ConfigLine *configLine;
  struct FirewallConfig *firewallTable = NULL;
  FILE *fp;

  if (argc !=2) {
    fprintf (stderr, "Exactly one argument required!\n");
    exit (1);
  }

  fp = fopen (argv[1], "r");
  if (!fp) {
    fprintf (stderr, "%s: Could not open %s!\n", argv[0], argv[1]);
    exit (1);
  }
  
  while (getline (&line, &len, fp) != -1) {
    configLine = parseLine (line, &errno);
    if (!configLine) {
      fprintf (stderr, "Parsing error in line %s; errno = %c !\n", line, errno); 
      exit (1);
    }
    
    firewallTable = addLine (configLine, firewallTable, &errno);
    if (!firewallTable) {
      fprintf (stderr, "Parsing error in line %s; errno = %c !\n", line, errno); 
      exit (1);
    }
    free (line);
    line = NULL;
  }
  firewallTable = firewallTableSort (firewallTable);
  
  printf ("Table after sorting\n");
    
  printTable (firewallTable);

  exit (0);
}