c programming optimize packet forwarder - c

Question

I have written UDP packet forwarder which opens UDP port and it continuously listen on perticolar socket and when data comes to it, it forwards data to another end point.
Problem I am facing is while running process for longer duration its process eats up almost 50% of system memory and other process suffers from it.
I have use PCRE library for some regex checking but it seems like main cause of problem how can i optimize my code that can run for infinite without any memory issue.
below is my code i have use of PCRE regex and socket forwarder.
int parse(char *str){
pcre *reCompiled;
pcre_extra *pcreExtra;
int pcreExecRet;
int subStrVec[30];
const char *pcreErrorStr;
int pcreErrorOffset;
int returnval;
char *aStrRegex;
char **aLineToMatch;
const char *psubStrMatchStr;
int j;
//*aLineToMatch = str;
aStrRegex = "(.*)(\"ABC\":)(\\d+)+";
//printf("Regex to use: %s\n", aStrRegex);
// First, the regex string must be compiled.
reCompiled = pcre_compile(aStrRegex, 0, &pcreErrorStr, &pcreErrorOffset, NULL);
/* OPTIONS (second argument) (||'ed together) can be:
PCRE_ANCHORED -- Like adding ^ at start of pattern.
PCRE_CASELESS -- Like m//i
PCRE_DOLLAR_ENDONLY -- Make $ match end of string regardless of \n's
No Perl equivalent.
PCRE_DOTALL -- Makes . match newlins too. Like m//s
PCRE_EXTENDED -- Like m//x
PCRE_EXTRA --
PCRE_MULTILINE -- Like m//m
PCRE_UNGREEDY -- Set quantifiers to be ungreedy. Individual quantifiers
may be set to be greedy if they are followed by "?".
PCRE_UTF8 -- Work with UTF8 strings.
*/
// pcre_compile returns NULL on error, and sets pcreErrorOffset & pcreErrorStr
if(reCompiled == NULL) {
printf("ERROR: Could not compile '%s': %s\n", aStrRegex, pcreErrorStr);
exit(1);
} /* end if */
// Optimize the regex
pcreExtra = pcre_study(reCompiled, 0, &pcreErrorStr);
/* pcre_study() returns NULL for both errors and when it can not optimize the regex. The last argument is how one checks for
errors (it is NULL if everything works, and points to an error string otherwise. */
if(pcreErrorStr != NULL) {
printf("ERROR: Could not study '%s': %s\n", aStrRegex, pcreErrorStr);
exit(1);
}
/* Try to find the regex in aLineToMatch, and report results. */
pcreExecRet = pcre_exec(reCompiled,
pcreExtra,
str,
strlen(str), // length of string
0, // Start looking at this point
0, // OPTIONS
subStrVec,
30); // Length of subStrVec
/* pcre_exec OPTIONS (||'ed together) can be:
PCRE_ANCHORED -- can be turned on at this time.
PCRE_NOTBOL
PCRE_NOTEOL
PCRE_NOTEMPTY */
// Report what happened in the pcre_exec call..
//printf("pcre_exec return: %d\n", pcreExecRet);
if(pcreExecRet < 0) { // Something bad happened..
returnval = -1;
switch(pcreExecRet) {
case PCRE_ERROR_NOMATCH : log_message("String did not match the pattern"); break;
case PCRE_ERROR_NULL : log_message("Something was null"); break;
case PCRE_ERROR_BADOPTION : log_message("A bad option was passed"); break;
case PCRE_ERROR_BADMAGIC : log_message("Magic number bad (compiled re corrupt?)"); break;
case PCRE_ERROR_UNKNOWN_NODE : log_message("Something kooky in the compiled re"); break;
case PCRE_ERROR_NOMEMORY : log_message("Ran out of memory"); break;
default : log_message("Unknown error"); break;
} /* end switch */
} else {
//printf("Result: We have a match!\n");
// At this point, rc contains the number of substring matches found...
if(pcreExecRet == 0) {
pcreExecRet = 30 / 3;
} /* end if */
// PCRE contains a handy function to do the above for you:
for(j=0; j<pcreExecRet; j++) {
pcre_get_substring(str, subStrVec, pcreExecRet, j, &(psubStrMatchStr));
} /* end for */
returnval = atoi(psubStrMatchStr);
// Free up the substring
pcre_free_substring(psubStrMatchStr);
} /* end if/else */
// Free up the regular expression.
pcre_free(reCompiled);
// Free up the EXTRA PCRE value (may be NULL at this point)
if(pcreExtra != NULL) {
#ifdef PCRE_CONFIG_JIT
pcre_free_study(pcreExtra);
#else
pcre_free(pcreExtra);
#endif
}
return returnval;
}
-------------------Udp Listener---------------
while (1) {
n = recvfrom(sock_receiver,buf,2048,0,(struct sockaddr *)&from,&sender_length);
if (n < 0) error("recvfrom");
//write(1,"Received a datagram: ",21);
// printf("n = %d\n", n);
// printf("length of buffer = %lu\n", strlen(buf));
// write(1,buf,n);
strncpy(str, buf, n);
str[n] = '\0'; // IMPORTANT!
value = parse(str);
if(curTime != get_hour()){
//sprintf(temp_str,"Counter",minute,get_minute());
log_message("Counter reset");
reset_component_hits(components);
//reset_component_hits(dropped_msg);
curTime = get_hour();
}
if(value >=0 && components[value] < component_limit && value < max_component){
n = sendto(sock_forwarder,buf,n,0,(const struct sockaddr *)&sender,sender_length);
if (n < 0){
error("sendto");
}
components[value] = components[value]+1;
}else{
if(value < 0 ) {
error_msg = "Unable to parse component";
}else if(value >= max_component){
error_msg = "value not found in valid component list";
}else if(components[value] >= component_limit) {
error_msg = "Rate limit exceeded";
}else {
error_msg = "Message dropped for Unknown reason";
}
sprintf(temp_str,"[Component:%d] %s",value,error_msg);
log_message(temp_str);
bzero(temp_str,100);
bzero(error_msg,100);
}
// print_array(components);
// print_array(dropped_msg);
bzero(buf,2048);
bzero(str,2048);
}