apportate/src/http.c

#include "headers.h"

const char REQ_HTTP[] = 
    {
    "GET %s HTTP/1.0\r\nHost: %s\r\n\r\n"
    };


int reqgen_http(const char *path, const char *fqdn, char **nbuf)
    {
    int buflen;

    buflen = (strlen(REQ_HTTP) + strlen(path) + strlen(fqdn) + 1);

    if( !(*nbuf = calloc(buflen, sizeof(char))))
	{
	return(ERRMEM);
	}

    sprintf(*nbuf, REQ_HTTP, path, fqdn);


    return(0);
    }

int resp_parse_http(char *data)
    {
    char *buf;

    if( NULL == (buf = calloc(4, sizeof(char))))
	{
	goto err;
	}

    /* there are nine characters between the start of data and the first character of the response code */
    data += 9;
    memcpy(buf, data, 3);
    return(atoi(buf));

    err:
    return(0);
    }

/* http_header_extract - return the value corresponding to a key if it exists in an http response, otherwise null */
/* key - key to extract corresponding value */
/* data - response header from which to extract key's value */
char *http_get_keyval(char *key, char *data)
    {
    char *buf;
    /* data indices */
    char *d_ind, *d_ind2;

    buf = NULL;
    d_ind = d_ind2 = data;


    /* we ensure that our key and each key we compare to are lower-case because some */
    /* servers will return mixed-case keys and others single-case. by doing this we */
    /* can use full key specifiers, which avoids false matches that would occur as a */
    /* result of using partial key specifiers e.g "location" instead of "ocation". */
    key = buftolower(key);
    

    for(;*data !=  '\0'; data++)
	{
	if(NULL != buf)
	    {
	    free(buf);
	    buf = NULL;

	    for(; '\n' != *(data - 1); data++);
	    d_ind = d_ind2 = data;
	    }

	for(; *d_ind != ':'; d_ind++);
	buf = substr_extract(data, 0, (d_ind - data));

	buf = buftolower(buf);

	if(!strcmp(key, buf))
	    {
	    free(buf);
	    for(data = d_ind+2; *(1+d_ind) != '\n'; d_ind++);

	    buf = substr_extract(data, 0, (d_ind - data));
	    return(buf);
	    }
	}
    
    return(NULL);
    }