apportate/src/main.c

#include "headers.h"


enum 
    {
    /* display a status bar */
    /* currently not implemented */
    B,
    /* put the file somewhere other than the current directory */
    O,
    /* silence all output -- the default */
    /* note that if -q is passed explicitly, it will irrevocably override -v and -b */
    Q,
    /* increase the verbosity level. higher levels imply you want the content lower levels would provide */
    /* all verbose output 
       is sent to stderr for ease of capture                                          */
    /* 0:  no informational, statistical or debug output                                                 */
    /* 1:  informational output (Sending request FOO to host BAR, Received response header BAZ, etc)     */
    /* 2:  statistical. informational+size of header and body in bytes, round-trip time, etc             */
    /* 3+: debug. statistical+all internal state changes                                                 */
    /* currently we only implement 1 */
    V
    };


char param[4] = {0};
/* below is to accompany param[O] */
char *outpath; 

int main(int argc, char **argv)
    {
    int i, translen, gotheader;
    int sockd;
    char *recvbuf;
    char *sendbufp, *offsetp, *errstr;
    FILE *filed;
    struct tls *tlsc;
    uri uristruct;

    i = translen = sockd = 0;
    sendbufp = offsetp = 0;
    if( (recvbuf = malloc(BUFSIZ+1)) == NULL)
	{
	errstr = "failed to init";
	goto err;
	}

    filed = 0;
    tlsc = NULL;


    for(i = 0; (i = getopt(argc, argv, "bo:qv")) != -1; i = 0)
	{
	switch(i)
	    {
	    case 'b':
		param[B] = 1;
		break;

	    case 'o':
		param[O] = 1;
		outpath = optarg;
		break;

	    case 'q':
		param[Q] = 1;
		param[B] = 0;
		param[V] = 0;
		break;

	    case 'v':
		/* we handle v differently because we want to support different levels of verbosity */
		if(!param[Q])
		    {
		    param[V]++;
		    }
		break;

	    default:
		errstr = "[-vb] [-q] [-o <file>] uri";
		goto usage;
	    }
	}


    /* we should probably modify uri_parse to return a zero value on failure... */
    if(uri_parse(argv[optind], &uristruct))
	{
	errstr = "[-q|[-v -b]] [-o <file>] uri";
	goto usage;
	}

    /* if outpath isn't set because we haven't received a -o param, */
    /* then we should set the outpath to the final component of the */
    /* URI.                                                         */
    /* If we can't do that, we should just set it to 'default'.     */
    if(NULL == outpath && !strlen((outpath = (1 + strrchr(uristruct.path, '/')))))
	{
	outpath = "default";
	}

    /* generate our request */
    if( !(sendbufp = reqgen(&uristruct)))
	{
	errstr = "Unknown protocol.";
	goto err;
	}

    if(param[V])
	{
	fprintf(stderr, "request: %s\n", sendbufp);
	}

    /* having a routine or a global variable to track whether we need TLS would be */
    /* nice to add in the future */
    /* could probably store whether tls is necessary in a char within uristruct... */
    /* Note: at the moment, if the TLS pointer passed is non-NULL, */
    /* dial's return code can only be treated as an indicator of success. */

    if(!strcmp("https", uristruct.proto))
	{
	sockd = dial(uristruct.fqdn, uristruct.proto, &tlsc);
	}
    else
	{
	sockd = dial(uristruct.fqdn, uristruct.proto, NULL);
	}
    
    if(!sockd)
	{
	errstr = "Couldn't connect to the host using the specified protocol.";
	goto err;
	}

    if(tlsc)
	{
	translen = tls_write(tlsc, sendbufp, strlen(sendbufp));
	}
    else
	{
	translen = send(sockd, sendbufp, strlen(sendbufp), 0);
	}

    if(translen)
	{
	if(param[V])
	    {
	    printf("send: %d bytes\n", translen);
	    }
	}
    else
	{
	errstr = "Couldn't transmit data.";
	goto err;
	}

    /* now for a slightly more complex version of the same routine: until we've encountered the    */
    /* delimiter, "\r\n\r\n", don't write to disk. Once we have, calculate the size of the body,   */
    /* then write that number of bytes to disk starting from the offset. Then, write everything    */
    /* until end of transmission.                                                                  */
    for(gotheader = 0, offsetp = NULL,  translen = 1; translen > 0; memset(recvbuf, 0, BUFSIZ+1))
	{
	if( NULL == tlsc)
	    {
	    printf("recv: %d bytes\n", translen = recv(sockd, recvbuf, BUFSIZ, 0));
	    }
	else
	    {
	    printf("recv: %d bytes\n", translen = tls_read(tlsc, recvbuf, BUFSIZ));
	    }

	/* if we haven't gotten the header and our delimiter isn't in the */
	/* received string, we're getting a multipart header and need to */
	/* skip over it. */
	/* right now we assume HTTP/S -- this is undesirable... */
	if( strcmp("gopher", uristruct.proto) && !gotheader)
	    {
	    if( NULL == (offsetp = strstr(recvbuf, "\r\n\r\n")))
		{
		printf("continuing...\n");
		continue;
		}
	    else
		{
		gotheader = 1;
		offsetp += 4;
		printf("got the header\n");
		}
	    }
	
	if( !filed && !(filed = fopen(outpath, "w")))
	    {
	    errstr = "couldn't open file";
	    goto err;
	    }

	fwrite(offsetp, sizeof(char), (translen - (offsetp - recvbuf)), filed);
	offsetp = recvbuf;
	}
    free(recvbuf);
    close(sockd);
    fclose(filed);
    
    
    exit(EXIT_SUCCESS);


    err:
    fprintf(stderr, "%s: %s\n", argv[0], errstr);
    exit(EXIT_FAILURE);

    usage:
    fprintf(stderr, "usage: %s: %s\n", argv[0], errstr);
    exit(EXIT_FAILURE);

    }