/* Opens a large number of tcp connections and sends
 * messages over them. This is used for stress-testing.
 *
 * Params
 * -t	target address (default 127.0.0.1)
 * -p	target port (default 13514)
 * -n	number of target ports (targets are in range -p..(-p+-n-1)
 *      Note -c must also be set to at LEAST the number of -n!
 * -c	number of connections (default 1)
 * -m	number of messages to send (connection is random)
 * -i	initial message number (optional)
 * -P	PRI to be used for generated messages (default is 167).
 *      Specify the plain number without leading zeros
 * -d   amount of extra data to add to message. If present, the
 *      number itself will be added as third field, and the data
 *      bytes as forth. Add -r to randomize the amount of extra
 *      data included in the range 1..(value of -d).
 * -r	randomize amount of extra data added (-d must be > 0)
 * -f	support for testing dynafiles. If given, include a dynafile ID
 *      in the range 0..(f-1) as the SECOND field, shifting all field values
 *      one field to the right. Zero (default) disables this functionality.
 * -M   the message to be sent. Disables all message format options, as
 *      only that exact same message is sent.
 * -I   read specified input file, do NOT generate own test data. The test
 *      completes when eof is reached.
 * -B   The specified file (-I) is binary. No data processing is done by
 *      tcpflood. If multiple connections are specified, data is read in
 *      chunks and spread across the connections without taking any record
 *      delemiters into account.
 * -C	when input from a file is read, this file is transmitted -C times
 *      (C like cycle, running out of meaningful option switches ;))
 * -D	randomly drop and re-establish connections. Useful for stress-testing
 *      the TCP receiver.
 * -F	USASCII value for frame delimiter (in octet-stuffing mode), default LF
 *
 * Part of the testbench for rsyslog.
 *
 * Copyright 2009, 2010 Rainer Gerhards and Adiscon GmbH.
 *
 * This file is part of rsyslog.
 *
 * Rsyslog is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Rsyslog is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Rsyslog.  If not, see <http://www.gnu.org/licenses/>.
 *
 * A copy of the GPL can be found in the file "COPYING" in this distribution.
 */
#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <assert.h>
#include <unistd.h>
#include <string.h>
#include <netinet/in.h>
#include <sys/resource.h>

#define EXIT_FAILURE 1
#define INVALID_SOCKET -1
/* Name of input file, must match $IncludeConfig in test suite .conf files */
#define NETTEST_INPUT_CONF_FILE "nettest.input.conf" /* name of input file, must match $IncludeConfig in .conf files */

#define MAX_EXTRADATA_LEN 100*1024

static char *targetIP = "127.0.0.1";
static char *msgPRI = "167";
static int targetPort = 13514;
static int numTargetPorts = 1;
static int dynFileIDs = 0;
static int extraDataLen = 0; /* amount of extra data to add to message */
static int bRandomizeExtraData = 0; /* randomize amount of extra data added */
static int numMsgsToSend; /* number of messages to send */
static int numConnections = 1; /* number of connections to create */
static int *sockArray;  /* array of sockets to use */
static int msgNum = 0;	/* initial message number to start with */
static int bShowProgress = 1; /* show progress messages */
static int bRandConnDrop = 0; /* randomly drop connections? */
static char *MsgToSend = NULL; /* if non-null, this is the actual message to send */
static int bBinaryFile = 0;	/* is -I file binary */
static char *dataFile = NULL;	/* name of data file, if NULL, generate own data */
static int numFileIterations = 1;/* how often is file data to be sent? */
static char frameDelim = '\n';	/* default frame delimiter */
FILE *dataFP = NULL;		/* file pointer for data file, if used */
static long nConnDrops = 0;	/* counter: number of time connection was dropped (-D option) */


/* open a single tcp connection
 */
int openConn(int *fd)
{
	int sock;
	struct sockaddr_in addr;
	int port;
	int retries = 0;
	int rnd;

	if((sock=socket(AF_INET, SOCK_STREAM, 0))==-1) {
		perror("socket()");
		return(1);
	}

	/* randomize port if required */
	if(numTargetPorts > 1) {
		rnd = rand(); /* easier if we need value for debug messages ;) */
		port = targetPort + (rnd % numTargetPorts);
	} else {
		port = targetPort;
	}
	memset((char *) &addr, 0, sizeof(addr));
	addr.sin_family = AF_INET;
	addr.sin_port = htons(port);
	if(inet_aton(targetIP, &addr.sin_addr)==0) {
		fprintf(stderr, "inet_aton() failed\n");
		return(1);
	}
	while(1) { /* loop broken inside */
		if(connect(sock, (struct sockaddr*)&addr, sizeof(addr)) == 0) {
			break;
		} else {
			if(retries++ == 50) {
				perror("connect()");
				fprintf(stderr, "connect() failed\n");
				return(1);
			} else {
				usleep(100000); /* ms = 1000 us! */
			}
		}
	} 

	*fd = sock;
	return 0;
}


/* open all requested tcp connections
 * this includes allocating the connection array
 */
int openConnections(void)
{
	int i;
	char msgBuf[128];
	size_t lenMsg;

	if(bShowProgress)
		write(1, "      open connections", sizeof("      open connections")-1);
	sockArray = calloc(numConnections, sizeof(int));
	for(i = 0 ; i < numConnections ; ++i) {
		if(i % 10 == 0) {
			if(bShowProgress)
				printf("\r%5.5d", i);
		}
		if(openConn(&(sockArray[i])) != 0) {
			printf("error in trying to open connection i=%d\n", i);
			return 1;
		}
	}
	lenMsg = sprintf(msgBuf, "\r%5.5d open connections\n", i);
	write(1, msgBuf, lenMsg);

	return 0;
}


/* we also close all connections because otherwise we may get very bad
 * timing for the syslogd - it may not be able to process all incoming
 * messages fast enough if we immediately shut down.
 * TODO: it may be an interesting excercise to handle that situation
 * at the syslogd level, too
 * rgerhards, 2009-04-14
 */
void closeConnections(void)
{
	int i;
	size_t lenMsg;
	struct linger ling;
	char msgBuf[128];

	if(bShowProgress)
		write(1, "      close connections", sizeof("      close connections")-1);
	for(i = 0 ; i < numConnections ; ++i) {
		if(i % 10 == 0) {
			if(bShowProgress) {
				lenMsg = sprintf(msgBuf, "\r%5.5d", i);
				write(1, msgBuf, lenMsg);
			}
		}
		if(sockArray[i] != -1) {
			/* we try to not overrun the receiver by trying to flush buffers
			 * *during* close(). -- rgerhards, 2010-08-10
			 */
			ling.l_onoff = 1;
			ling.l_linger = 1;
			setsockopt(sockArray[i], SOL_SOCKET, SO_LINGER, &ling, sizeof(ling));
			close(sockArray[i]);
		}
	}
	lenMsg = sprintf(msgBuf, "\r%5.5d close connections\n", i);
	write(1, msgBuf, lenMsg);

}


/* generate the message to be sent according to program command line parameters.
 * this has been moved to its own function as we now have various different ways
 * of constructing test messages. -- rgerhards, 2010-03-31
 */
static inline void
genMsg(char *buf, size_t maxBuf, int *pLenBuf)
{
	int edLen; /* actual extra data length to use */
	char extraData[MAX_EXTRADATA_LEN + 1];
	char dynFileIDBuf[128] = "";
	static int numMsgsGen = 0;
	int done;

	if(dataFP != NULL) {
		/* get message from file */
		do {
			done = 1;
			*pLenBuf = fread(buf, 1, 1024, dataFP);
			if(feof(dataFP)) {
				if(--numFileIterations > 0)  {
					rewind(dataFP);
					done = 0; /* need new iteration */
				} else {
					*pLenBuf = 0;
					goto finalize_it;
				}
			}
		} while(!done); /* Attention: do..while()! */
	} else if(MsgToSend == NULL) {
		if(dynFileIDs > 0) {
			snprintf(dynFileIDBuf, maxBuf, "%d:", rand() % dynFileIDs);
		}
		if(extraDataLen == 0) {
			*pLenBuf = snprintf(buf, maxBuf, "<%s>Mar  1 01:00:00 172.20.245.8 tag msgnum:%s%8.8d:%c",
					       msgPRI, dynFileIDBuf, msgNum, frameDelim);
		} else {
			if(bRandomizeExtraData)
				edLen = ((long) rand() + extraDataLen) % extraDataLen + 1;
			else
				edLen = extraDataLen;
			memset(extraData, 'X', edLen);
			extraData[edLen] = '\0';
			*pLenBuf = snprintf(buf, maxBuf, "<%s>Mar  1 01:00:00 172.20.245.8 tag msgnum:%s%8.8d:%d:%s%c",
					       msgPRI, dynFileIDBuf, msgNum, edLen, extraData, frameDelim);
		}
	} else {
		/* use fixed message format from command line */
		*pLenBuf = snprintf(buf, maxBuf, "%s\n", MsgToSend);
	}

	if(numMsgsGen++ >= numMsgsToSend)
		*pLenBuf = 0; /* indicate end of run */

finalize_it: ;
}

/* send messages to the tcp connections we keep open. We use
 * a very basic format that helps identify the message
 * (via msgnum:<number>: e.g. msgnum:00000001:). This format is suitable
 * for extracton to field-based properties.
 * The first numConnection messages are sent sequentially, as are the
 * last. All messages in between are sent over random connections.
 * Note that message numbers start at 0.
 */
int sendMessages(void)
{
	int i = 0;
	int socknum;
	int lenBuf;
	int lenSend;
	char *statusText;
	char buf[MAX_EXTRADATA_LEN + 1024];

	if(dataFile == NULL) {
		printf("Sending %d messages.\n", numMsgsToSend);
		statusText = "messages";
	} else {
		printf("Sending file '%s' %d times.\n", dataFile, numFileIterations);
		statusText = "kb";
	}
	if(bShowProgress)
		printf("\r%8.8d %s sent", 0, statusText);
	while(1) { /* broken inside loop! */
		if(i < numConnections)
			socknum = i;
		else if(i >= numMsgsToSend - numConnections)
			socknum = i - (numMsgsToSend - numConnections);
		else {
			int rnd = rand();
			socknum = rnd % numConnections;
		}
		genMsg(buf, sizeof(buf), &lenBuf); /* generate the message to send according to params */
		if(lenBuf == 0)
			break; /* end of processing! */
		if(sockArray[socknum] == -1) {
			/* connection was dropped, need to re-establish */
			if(openConn(&(sockArray[socknum])) != 0) {
				printf("error in trying to re-open connection %d\n", socknum);
				exit(1);
			}
		}
		lenSend = send(sockArray[socknum], buf, lenBuf, 0);
		if(lenSend != lenBuf) {
			printf("\r%5.5d\n", i);
			fflush(stdout);
			perror("send test data");
			printf("send() failed at socket %d, index %d, msgNum %d\n",
				sockArray[socknum], i, msgNum);
			fflush(stderr);
			return(1);
		}
		if(i % 100 == 0) {
			if(bShowProgress)
				printf("\r%8.8d", i);
		}
		if(bRandConnDrop) {
			/* if we need to randomly drop connections, see if we 
			 * are a victim
			 */
			if(rand() > (int) (RAND_MAX * 0.95)) {
				++nConnDrops;
				close(sockArray[socknum]);
				sockArray[socknum] = -1;
			}
		}
		++msgNum;
		++i;
	}
	printf("\r%8.8d %s sent\n", i, statusText);

	return 0;
}


/* Run the test.
 * rgerhards, 2009-04-03
 */
int main(int argc, char *argv[])
{
	int ret = 0;
	int opt;
	struct sigaction sigAct;
	static char buf[1024];

	srand(time(NULL));	/* seed is good enough for our needs */

	/* on Solaris, we do not HAVE MSG_NOSIGNAL, so for this reason
	 * we block SIGPIPE (not an issue for this program)
	 */
	memset(&sigAct, 0, sizeof(sigAct));
	sigemptyset(&sigAct.sa_mask);
	sigAct.sa_handler = SIG_IGN;
	sigaction(SIGPIPE, &sigAct, NULL);

	setvbuf(stdout, buf, _IONBF, 48);
	
	if(!isatty(1))
		bShowProgress = 0;

	while((opt = getopt(argc, argv, "f:F:t:p:c:C:m:i:I:P:d:Dn:M:rB")) != -1) {
		switch (opt) {
		case 't':	targetIP = optarg;
				break;
		case 'p':	targetPort = atoi(optarg);
				break;
		case 'n':	numTargetPorts = atoi(optarg);
				break;
		case 'c':	numConnections = atoi(optarg);
				break;
		case 'C':	numFileIterations = atoi(optarg);
				break;
		case 'm':	numMsgsToSend = atoi(optarg);
				break;
		case 'i':	msgNum = atoi(optarg);
				break;
		case 'P':	msgPRI = optarg;
				break;
		case 'd':	extraDataLen = atoi(optarg);
				if(extraDataLen > MAX_EXTRADATA_LEN) {
					fprintf(stderr, "-d max is %d!\n",
						MAX_EXTRADATA_LEN);
					exit(1);
				}
				break;
		case 'D':	bRandConnDrop = 1;
				break;
		case 'r':	bRandomizeExtraData = 1;
				break;
		case 'f':	dynFileIDs = atoi(optarg);
				break;
		case 'F':	frameDelim = atoi(optarg);
				break;
		case 'M':	MsgToSend = optarg;
				break;
		case 'I':	dataFile = optarg;
				/* in this mode, we do not know the num messages to send, so
				 * we set a (high) number to keep the code happy.
				 */
				numMsgsToSend = 1000000;
				break;
		case 'B':	bBinaryFile = 1;
				break;
		default:	printf("invalid option '%c' or value missing - terminating...\n", opt);
				exit (1);
				break;
		}
	}

	if(numConnections > 20) {
		/* if we use many (whatever this means, 20 is randomly picked)
		 * connections, we need to make sure we have a high enough
		 * limit. -- rgerhards, 2010-03-25
		 */
		struct rlimit maxFiles;
		maxFiles.rlim_cur = numConnections + 20;
		maxFiles.rlim_max = numConnections + 20;
		if(setrlimit(RLIMIT_NOFILE, &maxFiles) < 0) {
			perror("setrlimit to increase file handles failed");
			exit(1);
		}
	}
	
	if(dataFile != NULL) {
		if((dataFP = fopen(dataFile, "r")) == NULL) {
			perror(dataFile);
			exit(1);
		}
	}

	if(openConnections() != 0) {
		printf("error opening connections\n");
		exit(1);
	}

	if(sendMessages() != 0) {
		printf("error sending messages\n");
		exit(1);
	}

	closeConnections(); /* this is important so that we do not finish too early! */

	if(nConnDrops > 0)
		printf("-D option initiated %ld connection closures\n", nConnDrops);

	printf("End of tcpflood Run\n");

	exit(ret);
}