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Labs/Lab4/echod.c

+/*
+ * CSCI 315 Operating Systems Design
+ * Author: L. Felipe Perrone
+ * Date: 2010-02-16
+ * Copyright (c) 2011 Bucknell University
+ *
+ * Permission is hereby granted, free of charge, to any individual
+ * or institution obtaining a copy of this software and associated
+ * documentation files (the "Software"), to use, copy, modify, and
+ * distribute without restriction, provided that this copyright
+ * and permission notice is maintained, intact, in all copies and
+ * supporting documentation.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL BUCKNELL UNIVERSITY BE LIABLE FOR ANY CLAIM, DAMAGES
+ * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
+ * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/uio.h>
+#include <unistd.h>
+#include <netinet/in.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define BUFFER_SIZE 512 // length of message buffer    
+#define	QLEN 6   // length of request queue
+
+#define FOREVER 1
+#define TRUE 1
+#define FALSE 0
+
+int	num_requests = 0;  // tally of client requests
+
+/*------------------------------------------------------------------------
+ * Program:   echod - a server for echo requests
+ *
+ * Purpose:   repeatedly execute the following:
+ *    (0) wait for a connection request from client
+ *		(1) wait for a null-terminated string from client
+ *		(2) send back the same string to client 
+ *		(3) close the connection
+ *		(4) go back to step (0)
+ *
+ * Usage:    echod [ port ]
+ *
+ *		 port  - a port number in user space
+ *
+ *------------------------------------------------------------------------
+ */
+
+int 
+main (int argc, char* argv[]) {
+
+	struct sockaddr_in sad;  // structure to hold server's address	
+	struct sockaddr_in cad;  // structure to hold client's address	
+	int sd, sd2;	           // socket descriptors			
+	int port;		             // protocol port number		
+	socklen_t alen;	         // length of address			
+	char in_msg[BUFFER_SIZE];  // buffer for incoming message
+
+	// prepare address data structure
+
+	// The memset call is ESSENTIAL!
+	// if you don't do this every time you create a sockaddr struct, you will 
+	// see some pretty strange behaviour
+	memset((char *)&sad,0,sizeof(sad)); // zero out sockaddr structure
+
+	sad.sin_family = AF_INET;	          // set family to Internet	        
+	sad.sin_addr.s_addr = INADDR_ANY;   // set the local IP address	
+
+	// verify usage
+
+	if (argc > 1) {			
+		port = atoi(argv[1]);	        
+	}
+	else {
+		printf("Usage: %s [ port ]\n", argv[0]);
+		exit(-1);
+	}
+
+	if (port > 0)	
+		// test for illegal value	
+		sad.sin_port = htons((u_short)port);
+	else {				
+		// print error message and exit	
+		fprintf(stderr,"ECHOD: bad port number %s\n", argv[1]);
+		exit(-1);
+	}
+
+	// create socket 
+
+	sd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
+	if (sd < 0) {
+		perror("ECHOD: socket creation failed");
+		exit(-1);
+	}
+
+	// assign IP/port number to socket where connections come in 
+
+	if (bind(sd, (struct sockaddr *)&sad, sizeof(sad)) < 0) {
+		perror("ECHOD: bind failed");
+		exit(-1);
+	}
+
+	// set up socket to receive incomming connections 
+
+	if (listen(sd, QLEN) < 0) {
+		perror("ECHOD: listen failed");
+		exit(-1);
+	}
+
+	// main server loop - accept and handle requests 
+
+	while (FOREVER) {
+		alen = sizeof(cad);
+
+		if ( (sd2 = accept(sd, (struct sockaddr *)&cad, &alen)) < 0) {
+			perror("ECHOD: accept failed\n");
+			exit(-1);
+		}
+
+		num_requests++;
+
+		// receive the string sent by client
+		strcpy(in_msg, "");
+		recv(sd2, in_msg, BUFFER_SIZE, 0);
+	 	printf("done");	
+
+		
+		// send the received string back to client
+		//send(sd, buf, len flags);
+		send(sd2, in_msg, BUFFER_SIZE, 0); 
+
+		close(sd2);
+}
+}

Labs/Lab4/echoreq.c

+/*CSCI 315 Operating Systems Design
+ * Author: L. Felipe Perrone
+ * Date: 2014-09-21
+ * Copyright (c) 2014 Bucknell University
+ *
+ * Permission is hereby granted, free of charge, to any individual
+ * or institution obtaining a copy of this software and associated
+ * documentation files (the "Software"), to use, copy, modify, and
+ * distribute without restriction, provided that this copyright
+ * and permission notice is maintained, intact, in all copies and
+ * supporting documentation.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL BUCKNELL UNIVERSITY BE LIABLE FOR ANY CLAIM, DAMAGES
+ * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
+ * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#define BUFFER_SIZE 512
+#define TRUE 1
+#define FALSE 0
+
+/*------------------------------------------------------------------------
+ * Program:   echoreq
+ *
+ * Purpose:  allocate a socket, connect to a server, transfer requested
+ *            file to local host, and print file contents to stdout
+ *
+ * Usage:    echoreq [ host ] [ port ] [ string ] 
+ *
+ *               host  - name of a computer on which server is executing
+ *               port  - protocol port number server is using
+ *     string - a string in double quotes
+ *     
+ *------------------------------------------------------------------------
+ */
+
+int
+main(int argc, char* argv[]) {
+
+        struct  hostent  *ptrh;  // pointer to a host table entry       
+        struct  sockaddr_in sad; // structure to hold an IP address     
+
+        int     sd;                              // socket descriptor                   
+        int     port;                          // protocol port number          
+        char *host;                // pointer to host name              
+        char  in_msg[BUFFER_SIZE]; // buffer for incoming message
+
+        int ret_val;
+  	sad.sin_family = AF_INET;                 // set family to Internet     
+
+        // verify usage
+
+        if (argc < 4) {
+                printf("Usage: %s [ host ] [ port ] [ string ]\n", argv[0]);
+                exit(-1);
+        }
+
+        host = argv[1];
+        port = atoi(argv[2]);
+
+        if (port > 0)
+                // test for legal value         
+                sad.sin_port = htons((u_short)port);
+        else {
+                // print error message and exit 
+                printf("ECHOREQ: bad port number %s\n", argv[2]);
+                exit(-1);
+        }
+
+        // convert host name to equivalent IP address and copy to sad 
+
+        ptrh = gethostbyname(host);
+
+        if ( ((char *)ptrh) == NULL ) {
+                printf("ECHOREQ: invalid host: %s\n", host);
+                exit(-1);
+        }
+
+        memcpy(&sad.sin_addr, ptrh->h_addr, ptrh->h_length);
+
+        // create socket 
+
+        sd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
+        if (sd < 0) {
+                printf("ECHOREQ: socket creation failed\n");
+                exit(-1);
+        }
+
+        // connect the socket to the specified server 
+
+        if (connect(sd, (struct sockaddr *)&sad, sizeof(sad)) < 0) {
+                perror("ECHOREQ: connect failed");
+                exit(-1);
+        }
+
+        // send message to server
+        send(sd, in_msg, BUFFER_SIZE, 0);
+	printf("sent");
+           // send the received string back to client
+			printf("\n"); 
+                //                 //send(sd, buf, len flags);
+        strcpy(in_msg, "");
+	recv(sd, in_msg, BUFFER_SIZE, 0);
+
+                //
+        // receive message echoed back by server
+
+        printf("ECHOREQ: from server= %s\n", in_msg);
+
+        // close the socket   
+        close(sd);
+
+        // terminate the client program gracefully 
+        return(0);
+}
+