path: root/plugins/check_curl.c

/*****************************************************************************
*
* Monitoring check_curl plugin
*
* License: GPL
* Copyright (c) 1999-2017 Monitoring Plugins Development Team
*
* Description:
*
* This file contains the check_curl plugin
*
* This plugin tests the HTTP service on the specified host. It can test
* normal (http) and secure (https) servers, follow redirects, search for
* strings and regular expressions, check connection times, and report on
* certificate expiration times.
* 
* This plugin uses functions from the curl library, see
* http://curl.haxx.se
*
* This program 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.
*
* This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
*
*
*****************************************************************************/

const char *progname = "check_curl";
const char *copyright = "2006-2017";
const char *email = "devel@monitoring-plugins.org";

#include "common.h"
#include "utils.h"

#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#else
#define unsigned int size_t
#endif

#ifdef HAVE_STRING_H
#include <string.h>
#endif

#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif

#ifndef LIBCURL_PROTOCOL_HTTP
#error libcurl compiled without HTTP support, compiling check_curl plugin makes not much sense
#endif

#include "curl/curl.h"
#include "curl/easy.h"

#define DEFAULT_BUFFER_SIZE 2048
#define DEFAULT_SERVER_URL "/"
#define DEFAULT_HTTP_PORT 80
#define DEFAULT_HTTPS_PORT 443
#define MAX_PORT 65535

/* for buffers for header and body */
typedef struct {
	char *buf;
	size_t buflen;
	size_t bufsize;
} curlhelp_curlbuf;

/* for parsing the HTTP status line */
typedef struct {
	int http_major;   /* major version of the protocol, always 1 (HTTP/0.9
	                   * never reached the big internet most likely) */
	int http_minor;   /* minor version of the protocol, usually 0 or 1 */
	int http_code;    /* HTTP return code as in RFC 2145 */
	int http_subcode; /* Microsoft IIS extension, HTTP subcodes, see
	                   * http://support.microsoft.com/kb/318380/en-us */
	char *msg;        /* the human readable message */
	char *first_line; /* a copy of the first line */
} curlhelp_statusline;

char *server_address;
char *host_name;
char *server_url = DEFAULT_SERVER_URL;
unsigned short server_port = DEFAULT_HTTP_PORT;
char output_string_search[30] = "";
char *warning_thresholds = NULL;
char *critical_thresholds = NULL;
thresholds *thlds;
char user_agent[DEFAULT_BUFFER_SIZE];
int verbose = 0;
CURL *curl;
struct curl_slist *header_list = NULL;
curlhelp_curlbuf body_buf;
curlhelp_curlbuf header_buf;
curlhelp_statusline status_line;
char http_header[DEFAULT_BUFFER_SIZE];
long code;
long socket_timeout = DEFAULT_SOCKET_TIMEOUT;
double total_time;
char errbuf[CURL_ERROR_SIZE+1];
CURLcode res;
char url[DEFAULT_BUFFER_SIZE];
char msg[DEFAULT_BUFFER_SIZE];
char perfstring[DEFAULT_BUFFER_SIZE];
char string_expect[MAX_INPUT_BUFFER] = "";
char user_auth[MAX_INPUT_BUFFER] = "";
int onredirect = STATE_OK;
int use_ssl = FALSE;
int use_sni = TRUE;
int check_cert = FALSE;
int ssl_version = CURL_SSLVERSION_DEFAULT;
char *client_cert = NULL;
char *client_privkey = NULL;

int process_arguments (int, char**);
void print_help (void);
void print_usage (void);
void print_curl_version (void);
int curlhelp_initbuffer (curlhelp_curlbuf*);
int curlhelp_buffer_callback (void*, size_t , size_t , void*);
void curlhelp_freebuffer (curlhelp_curlbuf*);

int curlhelp_parse_statusline (char*, curlhelp_statusline *);
void curlhelp_free_statusline (curlhelp_statusline *);

void remove_newlines (char *);
void test_file (char *);

int
main (int argc, char **argv)
{
	int result = STATE_OK;

	setlocale (LC_ALL, "");
	bindtextdomain (PACKAGE, LOCALEDIR);
	textdomain (PACKAGE);

	/* Parse extra opts if any */
	argv = np_extra_opts (&argc, argv, progname);
	
	/* set defaults */
	snprintf( user_agent, DEFAULT_BUFFER_SIZE, "%s/v%s (monitoring-plugins %s)",
		progname, NP_VERSION, VERSION);

	/* parse arguments */
	if (process_arguments (argc, argv) == ERROR)
		usage4 (_("Could not parse arguments"));

	/* initialize curl */
	if (curl_global_init (CURL_GLOBAL_DEFAULT) != CURLE_OK)
		die (STATE_UNKNOWN, "HTTP UNKNOWN - curl_global_init failed\n");
		
	if ((curl = curl_easy_init()) == NULL)
		die (STATE_UNKNOWN, "HTTP UNKNOWN - curl_easy_init failed\n");

	if (verbose >= 3)
		curl_easy_setopt (curl, CURLOPT_VERBOSE, TRUE);

	/* initialize buffer for body of the answer */
	if (curlhelp_initbuffer(&body_buf) < 0)
		die (STATE_UNKNOWN, "HTTP CRITICAL - out of memory allocating buffer for body\n");
	curl_easy_setopt (curl, CURLOPT_WRITEFUNCTION, curlhelp_buffer_callback);
	curl_easy_setopt (curl, CURLOPT_WRITEDATA, (void *)&body_buf);

	/* initialize buffer for header of the answer */
	if (curlhelp_initbuffer( &header_buf ) < 0)
		die (STATE_UNKNOWN, "HTTP CRITICAL - out of memory allocating buffer for header\n" );
	curl_easy_setopt (curl, CURLOPT_HEADERFUNCTION, curlhelp_buffer_callback);
	curl_easy_setopt (curl, CURLOPT_WRITEHEADER, (void *)&header_buf);

	/* set the error buffer */
	curl_easy_setopt (curl, CURLOPT_ERRORBUFFER, errbuf);

	/* set timeouts */
	curl_easy_setopt (curl, CURLOPT_CONNECTTIMEOUT, socket_timeout);
	curl_easy_setopt (curl, CURLOPT_TIMEOUT, socket_timeout);
	
	/* compose URL */
	snprintf (url, DEFAULT_BUFFER_SIZE, "%s://%s%s", use_ssl ? "https" : "http",
		server_address, server_url);
	curl_easy_setopt (curl, CURLOPT_URL, url);

	/* set port */
	curl_easy_setopt (curl, CURLOPT_PORT, server_port);
	
	/* compose HTTP headers */
	snprintf (http_header, DEFAULT_BUFFER_SIZE, "Host: %s", host_name);
	header_list = curl_slist_append (header_list, http_header);
	curl_easy_setopt( curl, CURLOPT_HTTPHEADER, header_list );

	/* set SSL version, warn about unsecure or unsupported versions */
	if (use_ssl) {
		curl_easy_setopt (curl, CURLOPT_SSLVERSION, ssl_version);
	}

	/* client certificate and key to present to server (SSL) */
	if (client_cert)
		curl_easy_setopt (curl, CURLOPT_SSLCERT, client_cert);
	if (client_privkey)
		curl_easy_setopt (curl, CURLOPT_SSLKEY, client_privkey);
	
	/* per default if we have a CA verify both the peer and the
	 * hostname in the certificate, can be switched off later */
	curl_easy_setopt( curl, CURLOPT_SSL_VERIFYPEER, 2);
	curl_easy_setopt( curl, CURLOPT_SSL_VERIFYHOST, 2);

	/* backward-compatible behaviour, be tolerant in checks */
	if (!check_cert) {
		//TODO: depending on more options have aspects we want
		//to be tolerant about
		//curl_easy_setopt( curl, CURLOPT_SSL_VERIFYPEER, 1 );
		curl_easy_setopt (curl, CURLOPT_SSL_VERIFYPEER, 0);
		curl_easy_setopt (curl, CURLOPT_SSL_VERIFYHOST, 0);
	}

	/* set default or user-given user agent identification */
	curl_easy_setopt (curl, CURLOPT_USERAGENT, user_agent);

	/* authentication */
	if (strcmp(user_auth, ""))
		curl_easy_setopt (curl, CURLOPT_USERPWD, user_auth);

	/* TODO: parameter auth method, bitfield of following methods:
	 * CURLAUTH_BASIC (default)
	 * CURLAUTH_DIGEST 
	 * CURLAUTH_DIGEST_IE 
	 * CURLAUTH_NEGOTIATE 
	 * CURLAUTH_NTLM 
	 * CURLAUTH_NTLM_WB 
	 * 
	 * convenience tokens for typical sets of methods:
	 * CURLAUTH_ANYSAFE: most secure, without BASIC
	 * or CURLAUTH_ANY: most secure, even BASIC if necessary
	 * 
	 * curl_easy_setopt( curl, CURLOPT_HTTPAUTH, (long)CURLAUTH_DIGEST );
	 */
	 			
	/* TODO: --cacert: CA certificate file to verify SSL connection against (SSL) */
	//~ if( args_info.cacert_given ) {
		//~ curl_easy_setopt( curl, CURLOPT_CAINFO, args_info.cacert_arg );
	//~ }

	/* handle redirections */
	if (onredirect == STATE_DEPENDENT) {
		curl_easy_setopt (curl, CURLOPT_FOLLOWLOCATION, 1);
		/* TODO: handle the following aspects of redirection
			CURLOPT_POSTREDIR: method switch
			CURLINFO_REDIRECT_URL: custom redirect option
			CURLOPT_REDIRECT_PROTOCOLS
			CURLINFO_REDIRECT_COUNT
		*/
	}
		
	/* do the request */
	res = curl_easy_perform(curl);

	/* free header list, we don't need it anymore */
	curl_slist_free_all (header_list);

	/* Curl errors, result in critical Nagios state */
	if (res != CURLE_OK) {
		remove_newlines (errbuf);
		snprintf (msg, DEFAULT_BUFFER_SIZE, _("Invalid HTTP response received from host on port %d: %s\n"),
			server_port, status_line.msg, status_line.msg);
		die (STATE_CRITICAL, "HTTP CRITICAL - %s\n", msg);
	}

	/* we got the data and we executed the request in a given time, so we can append
	 * performance data to the answer always
	 */
	curl_easy_getinfo (curl, CURLINFO_TOTAL_TIME, &total_time);
	snprintf (perfstring, DEFAULT_BUFFER_SIZE, "time=%.6gs;%.6g;%.6g;%.6g size=%dB;;;0",
		total_time,
		0.0, 0.0,
		//~ args_info.warning_given ? args_info.warning_arg : 0.0,
		//~ args_info.critical_given ? args_info.critical_arg : 0.0,
		0.0,
		(int)body_buf.buflen);

	/* return a CRITICAL status if we couldn't read any data */
	if (strlen(header_buf.buf) == 0 && strlen(body_buf.buf) == 0) 
		die (STATE_CRITICAL, _("HTTP CRITICAL - No header received from host\n"));

	/* get status line of answer, check sanity of HTTP code */
	if (curlhelp_parse_statusline (header_buf.buf, &status_line) < 0) {
		snprintf (msg, DEFAULT_BUFFER_SIZE, "Unparseable status line in %.3g seconds response time|%s\n",
			code, total_time, perfstring);
		die (STATE_CRITICAL, "HTTP CRITICAL HTTP/1.x %d unknown - %s", code, msg);
	}

	/* get result code from cURL */
	curl_easy_getinfo (curl, CURLINFO_RESPONSE_CODE, &code);
	if (verbose>=2)
		printf ("* curl CURLINFO_RESPONSE_CODE is %d\n", code);

	/* print status line, header, body if verbose */
	if (verbose >= 2) {
		puts ("--- HEADER ---");
		puts (header_buf.buf);	
		puts ("--- BODY ---");
		puts (body_buf.buf);
	}
		
	/* illegal return codes result in a critical state */
	if (code >= 600 || code < 100) {
		die (STATE_CRITICAL, _("HTTP CRITICAL: Invalid Status (%d, %.40s)\n"), status_line.http_code, status_line.msg);
	/* server errors result in a critical state */
    	} else if (code >= 500) {
		result = STATE_CRITICAL;
    	/* client errors result in a warning state */
	} else if (code >= 400) {
		result = STATE_WARNING;
	/* check redirected page if specified */
	} else if (code >= 300) {
		if (onredirect == STATE_DEPENDENT) {
			code = status_line.http_code;
		}
		result = max_state_alt (onredirect, result);
		/* TODO: make sure the last status line has been
		   parsed into the status_line structure
		 */
	/* all other codes are considered ok */
	} else {
		result = STATE_OK;
	}

	/* check status codes, set exit status accordingly */
	if( status_line.http_code != code ) {
		die (STATE_CRITICAL, _("HTTP CRITICAL HTTP/%d.%d %d %s - different HTTP codes (cUrl has %ld)\n"),
			status_line.http_major, status_line.http_minor,
			status_line.http_code, status_line.msg, code);
	}

	/* Page and Header content checks go here */
	if (strlen (string_expect)) {
		if (!strstr (body_buf.buf, string_expect)) {
			strncpy(&output_string_search[0],string_expect,sizeof(output_string_search));
			if(output_string_search[sizeof(output_string_search)-1]!='\0') {
				bcopy("...",&output_string_search[sizeof(output_string_search)-4],4);
			}
			snprintf (msg, DEFAULT_BUFFER_SIZE, _("%sstring '%s' not found on '%s://%s:%d%s', "), msg, output_string_search, use_ssl ? "https" : "http", host_name ? host_name : server_address, server_port, server_url);
			result = STATE_CRITICAL;
		}
	}

	/* -w, -c: check warning and critical level */
	result = max_state_alt(get_status(total_time, thlds), result);

	//~ die (result, "HTTP %s: %s\n", state_text(result), msg);
	die (result, "HTTP %s HTTP/%d.%d %d %s - %s - %.3g seconds response time|%s\n",
		state_text(result), status_line.http_major, status_line.http_minor,
		status_line.http_code, status_line.msg, msg,
		total_time, perfstring);

	/* proper cleanup after die? */
	curlhelp_free_statusline(&status_line);
	curl_easy_cleanup (curl);
	curl_global_cleanup ();
	curlhelp_freebuffer(&body_buf);
	curlhelp_freebuffer(&header_buf);

	return result;
}

/* check whether a file exists */
void
test_file (char *path)
{
	if (access(path, R_OK) == 0)
		return;
	usage2 (_("file does not exist or is not readable"), path);
}

int
process_arguments (int argc, char **argv)
{
	int c;
	
	enum {
		SNI_OPTION
	};
	
	int option=0;
	static struct option longopts[] = {
		{"ssl", optional_argument, 0, 'S'},
		{"sni", no_argument, 0, SNI_OPTION},
		{"IP-address", required_argument, 0, 'I'},
		{"url", required_argument, 0, 'u'},
		{"port", required_argument, 0, 'p'},
		{"authorization", required_argument, 0, 'a'},
		{"string", required_argument, 0, 's'},
		{"onredirect", required_argument, 0, 'f'},
		{"client-cert", required_argument, 0, 'J'},
		{"private-key", required_argument, 0, 'K'},
		{"useragent", required_argument, 0, 'A'},
		{"certificate", required_argument, 0, 'C'},
		{0, 0, 0, 0}
	};

	if (argc < 2)
		usage ("\n");

	while (1) {
		c = getopt_long (argc, argv, "Vvht:c:w:A:H:I:a:p:s:u:f:C:J:K:S::", longopts, &option);
		if (c == -1 || c == EOF || c == 1)
			break;

		switch (c) {
		case 'h':
			print_help();
			exit(STATE_UNKNOWN);
			break;
		case 'V':
			print_revision(progname, NP_VERSION);
			print_curl_version();
			exit(STATE_UNKNOWN);
			break;
		case 'v':
			verbose++;
			break;
		case 't': /* timeout period */
			if (!is_intnonneg (optarg))
				usage2 (_("Timeout interval must be a positive integer"), optarg);
			else
				socket_timeout = (int)strtol (optarg, NULL, 10);
			break;
		case 'c': /* critical time threshold */
			critical_thresholds = optarg;
			break;
		case 'w': /* warning time threshold */
			warning_thresholds = optarg;
			break;
		case 'H': /* virtual host */
			host_name = strdup (optarg);
			break;
		case 'I': /* internet address */
			server_address = strdup (optarg);
			break;
		case 'u': /* URL path */
			server_url = strdup (optarg);
			break;
		case 'p': /* Server port */
			if (!is_intnonneg (optarg))
				usage2 (_("Invalid port number, expecting a non-negative number"), optarg);
			else {
				if( strtol(optarg, NULL, 10) > MAX_PORT)
					usage2 (_("Invalid port number, supplied port number is too big"), optarg);
				server_port = (unsigned short)strtol(optarg, NULL, 10);
			}
			break;
		case 'a': /* authorization info */
			strncpy (user_auth, optarg, MAX_INPUT_BUFFER - 1);
			user_auth[MAX_INPUT_BUFFER - 1] = 0;
			break;
		case 'A': /* useragent */
			snprintf (user_agent, DEFAULT_BUFFER_SIZE, optarg);
			break;
		case 'C': /* Check SSL cert validity */
#ifdef LIBCURL_FEATURE_SSL
			/* TODO: C:, check age of certificate for backward compatible
			 * behaviour, but we would later add more check conditions */
			check_cert = TRUE;
			goto enable_ssl;
#endif
		case 'J': /* use client certificate */
#ifdef LIBCURL_FEATURE_SSL
			test_file(optarg);
			client_cert = optarg;
			goto enable_ssl;
#endif
		case 'K': /* use client private key */
#ifdef LIBCURL_FEATURE_SSL
			test_file(optarg);
			client_privkey = optarg;
			goto enable_ssl;
#endif
		case 'S': /* use SSL */
#ifdef LIBCURL_FEATURE_SSL
		enable_ssl:
			use_ssl = TRUE;
			/* ssl_version initialized to CURL_SSLVERSION_TLSv1_0 as a default. Only set if it's non-zero.  This helps when we include multiple
			   parameters, like -S and -C combinations */
			ssl_version = CURL_SSLVERSION_TLSv1_0;
			if (c=='S' && optarg != NULL) {
				int got_plus = strchr(optarg, '+') != NULL;

				if (!strncmp (optarg, "1.2", 3))
					ssl_version = CURL_SSLVERSION_TLSv1_2;
				else if (!strncmp (optarg, "1.1", 3))
					ssl_version = CURL_SSLVERSION_TLSv1_1;
				else if (optarg[0] == '1')
					ssl_version = CURL_SSLVERSION_TLSv1_0;
				else if (optarg[0] == '3')
					ssl_version = CURL_SSLVERSION_SSLv3;
				else if (optarg[0] == '2')
					ssl_version = CURL_SSLVERSION_SSLv2;
				else
					usage4 (_("Invalid option - Valid SSL/TLS versions: 2, 3, 1, 1.1, 1.2 (with optional '+' suffix)"));
			}
			if (server_port == DEFAULT_HTTP_PORT)
				server_port = DEFAULT_HTTPS_PORT;
#else
			/* -C -J and -K fall through to here without SSL */
			usage4 (_("Invalid option - SSL is not available"));
#endif
			break;
		case SNI_OPTION: /* --sni is parsed, but ignored, the default is TRUE with libcurl */
			use_sni = TRUE;
			break;
		case 'f': /* onredirect */
			if (!strcmp (optarg, "ok"))
				onredirect = STATE_OK;
			else if (!strcmp (optarg, "warning"))
				onredirect = STATE_WARNING;
			else if (!strcmp (optarg, "critical"))
				onredirect = STATE_CRITICAL;
			else if (!strcmp (optarg, "unknown"))
				onredirect = STATE_UNKNOWN;
			else if (!strcmp (optarg, "follow"))
				onredirect = STATE_DEPENDENT;
			else usage2 (_("Invalid onredirect option"), optarg);
			//~ if (!strcmp (optarg, "stickyport"))
			//~ onredirect = STATE_DEPENDENT, followsticky = STICKY_HOST|STICKY_PORT;
		  //~ else if (!strcmp (optarg, "sticky"))
			//~ onredirect = STATE_DEPENDENT, followsticky = STICKY_HOST;
		  //~ else if (!strcmp (optarg, "follow"))
			//~ onredirect = STATE_DEPENDENT, followsticky = STICKY_NONE;
			if (verbose >= 2)
				printf(_("* Following redirects set to %s\n"), state_text(onredirect));
			break;
		case 's': /* string or substring */
			strncpy (string_expect, optarg, MAX_INPUT_BUFFER - 1);
			string_expect[MAX_INPUT_BUFFER - 1] = 0;
			break;
		case '?':
			/* print short usage statement if args not parsable */
			usage5 ();
			break;
		}
	}
	
	c = optind;

	if (server_address == NULL && c < argc)
		server_address = strdup (argv[c++]);

	if (host_name == NULL && c < argc)
		host_name = strdup (argv[c++]);

	if (server_address == NULL) {
		if (host_name == NULL)
			usage4 (_("You must specify a server address or host name"));
		else
			server_address = strdup (host_name);
	}

	set_thresholds(&thlds, warning_thresholds, critical_thresholds);

	if (critical_thresholds && thlds->critical->end>(double)socket_timeout)
		socket_timeout = (int)thlds->critical->end + 1;
	if (verbose >= 2)
		printf ("* Socket timeout set to %d seconds\n", socket_timeout);

  //~ if (http_method == NULL)
    //~ http_method = strdup ("GET");

	if (client_cert && !client_privkey)
		usage4 (_("If you use a client certificate you must also specify a private key file"));

  //~ if (virtual_port == 0)
    //~ virtual_port = server_port;

	return TRUE;
}

void
print_help (void)
{
	print_revision(progname, NP_VERSION);

	printf ("Copyright (c) 1999 Ethan Galstad <nagios@nagios.org>\n");
	printf ("Copyright (c) 2017 Andreas Baumann <abaumann@yahoo.com>\n");
	printf (COPYRIGHT, copyright, email);

	printf ("%s\n", _("This plugin tests the HTTP service on the specified host. It can test"));
	printf ("%s\n", _("normal (http) and secure (https) servers, follow redirects, search for"));
	printf ("%s\n", _("strings and regular expressions, check connection times, and report on"));
	printf ("%s\n", _("certificate expiration times."));
	printf ("\n");
	printf ("%s\n", _("It makes use of libcurl to do so. It tries to be as compatible to check_http"));
	printf ("%s\n", _("as possible."));

	printf ("\n\n");

	print_usage();
	
	printf (_("NOTE: One or both of -H and -I must be specified"));

	printf ("\n");

	printf (UT_HELP_VRSN);
	printf (UT_EXTRA_OPTS);

	printf (" %s\n", "-H, --hostname=ADDRESS");
	printf ("    %s\n", _("Host name argument for servers using host headers (virtual host)"));
	printf ("    %s\n", _("Append a port to include it in the header (eg: example.com:5000)"));
	printf (" %s\n", "-I, --IP-address=ADDRESS");
	printf ("    %s\n", _("IP address or name (use numeric address if possible to bypass DNS lookup)."));
	printf (" %s\n", "-p, --port=INTEGER");
	printf ("    %s", _("Port number (default: "));
	printf ("%d)\n", DEFAULT_HTTP_PORT);

#ifdef LIBCURL_FEATURE_SSL
	printf (" %s\n", "-S, --ssl=VERSION[+]");
	printf ("    %s\n", _("Connect via SSL. Port defaults to 443. VERSION is optional, and prevents"));
	printf ("    %s\n", _("auto-negotiation (2 = SSLv2, 3 = SSLv3, 1 = TLSv1, 1.1 = TLSv1.1,"));
	printf ("    %s\n", _("1.2 = TLSv1.2). With a '+' suffix, newer versions are also accepted."));
	printf ("    %s\n", _("Note: SSLv2 and SSLv3 are deprecated and are usually disabled in libcurl"));
	printf (" %s\n", "--sni");
	printf ("    %s\n", _("Enable SSL/TLS hostname extension support (SNI)"));
#if LIBCURL_VERSION_NUM >= 0x071801
	printf ("    %s\n", _("Note: --sni is the default in libcurl as SSLv2 and SSLV3 are deprecated and"));
	printf ("    %s\n", _("      SNI only really works since TLSv1.0"));
#else
	printf ("    %s\n", _("Note: SNI is not supported in libcurl before 7.18.1"));	
#endif
	printf (" %s\n", "-C, --certificate");
	printf ("    %s\n", _("Check validity of certificate"));
	printf (" %s\n", "-J, --client-cert=FILE");
	printf ("   %s\n", _("Name of file that contains the client certificate (PEM format)"));
	printf ("   %s\n", _("to be used in establishing the SSL session"));
	printf (" %s\n", "-K, --private-key=FILE");
	printf ("   %s\n", _("Name of file containing the private key (PEM format)"));
	printf ("   %s\n", _("matching the client certificate"));
#endif

	printf (" %s\n", "-s, --string=STRING");
	printf ("    %s\n", _("String to expect in the content"));
	printf (" %s\n", "-u, --url=PATH");
	printf ("    %s\n", _("URL to GET or POST (default: /)"));

	printf (" %s\n", "-a, --authorization=AUTH_PAIR");
	printf ("    %s\n", _("Username:password on sites with basic authentication"));
	printf (" %s\n", "-A, --useragent=STRING");
	printf ("    %s\n", _("String to be sent in http header as \"User Agent\""));
	printf (" %s\n", "-f, --onredirect=<ok|warning|critical|follow|sticky|stickyport>");
	printf ("    %s\n", _("How to handle redirected pages. sticky is like follow but stick to the"));
	printf ("    %s\n", _("specified IP address. stickyport also ensures port stays the same."));

	printf (UT_WARN_CRIT);

	printf (UT_CONN_TIMEOUT, DEFAULT_SOCKET_TIMEOUT);

	printf (UT_VERBOSE);

	printf (UT_SUPPORT);
}

void
print_usage (void)
{
	printf ("%s\n", _("Usage:"));
	printf (" %s -H <vhost> | -I <IP-address> [-u <uri>] [-p <port>]\n",progname);
	printf ("       [-J <client certificate file>] [-K <private key>]\n");
	printf ("       [-w <warn time>] [-c <critical time>] [-t <timeout>] [-a auth]\n");
	printf ("       [-f <ok|warning|critcal|follow>]\n");
	printf ("       [-A string] [-S <version>] [-C]\n");
	printf ("       [-v verbose]\n", progname);
	printf ("\n");
	printf ("%s\n", _("WARNING: check_curl is experimental. Please use"));
	printf ("%s\n\n", _("check_http if you need a stable version."));
}

void
print_curl_version (void)
{
	printf( "%s\n", curl_version());
}

int
curlhelp_initbuffer (curlhelp_curlbuf *buf)
{
	buf->bufsize = DEFAULT_BUFFER_SIZE;
	buf->buflen = 0;
	buf->buf = (char *)malloc ((size_t)buf->bufsize); 
	if (buf->buf == NULL) return -1;
	return 0;
}

int
curlhelp_buffer_callback (void *buffer, size_t size, size_t nmemb, void *stream)
{
	curlhelp_curlbuf *buf = (curlhelp_curlbuf *)stream;

	while (buf->bufsize < buf->buflen + size * nmemb + 1) {
		buf->bufsize *= buf->bufsize * 2;
		buf->buf = (char *)realloc (buf->buf, buf->bufsize);
		if (buf->buf == NULL) return -1;
	}

	memcpy (buf->buf + buf->buflen, buffer, size * nmemb);
	buf->buflen += size * nmemb;
	buf->buf[buf->buflen] = '\0';

	return (int)(size * nmemb);
}

void
curlhelp_freebuffer (curlhelp_curlbuf *buf)
{
	free (buf->buf);
	buf->buf = NULL;
}

/* TODO: when redirecting we get more than one HTTP header, make sure
 * we parse the last one
 */
int
curlhelp_parse_statusline (char *buf, curlhelp_statusline *status_line)
{
	char *first_line_end;
	char *p;
	size_t first_line_len;
	char *pp;

	first_line_end = strstr(buf, "\r\n");
	if (first_line_end == NULL) return -1;

	first_line_len = (size_t)(first_line_end - buf);
	status_line->first_line = (char *)malloc (first_line_len + 1);
	if (status_line->first_line == NULL) return -1;
	memcpy (status_line->first_line, buf, first_line_len);
	status_line->first_line[first_line_len] = '\0';

	/* protocol and version: "HTTP/x.x" SP */

	p = strtok(status_line->first_line, "/");
	if( p == NULL ) { free( status_line->first_line ); return -1; }
	if( strcmp( p, "HTTP" ) != 0 ) { free( status_line->first_line ); return -1; }

	p = strtok( NULL, "." );
	if( p == NULL ) { free( status_line->first_line ); return -1; }
	status_line->http_major = (int)strtol( p, &pp, 10 );
	if( *pp != '\0' ) { free( status_line->first_line ); return -1; }

	p = strtok( NULL, " " );
	if( p == NULL ) { free( status_line->first_line ); return -1; }
	status_line->http_minor = (int)strtol( p, &pp, 10 );
	if( *pp != '\0' ) { free( status_line->first_line ); return -1; }

	/* status code: "404" or "404.1", then SP */

	p = strtok( NULL, " ." );
	if( p == NULL ) { free( status_line->first_line ); return -1; }
	if( strchr( p, '.' ) != NULL ) {
		char *ppp;
		ppp = strtok( p, "." );
		status_line->http_code = (int)strtol( ppp, &pp, 10 );
		if( *pp != '\0' ) { free( status_line->first_line ); return -1; }

		ppp = strtok( NULL, "" );
		status_line->http_subcode = (int)strtol( ppp, &pp, 10 );
		if( *pp != '\0' ) { free( status_line->first_line ); return -1; }
	} else {
		status_line->http_code = (int)strtol( p, &pp, 10 );
		status_line->http_subcode = -1;
		if( *pp != '\0' ) { free( status_line->first_line ); return -1; }
	}

	/* Human readable message: "Not Found" CRLF */

	p = strtok( NULL, "" );
	if( p == NULL ) { free( status_line->first_line ); return -1; }
	status_line->msg = p;

	return 0;
}

void
curlhelp_free_statusline (curlhelp_statusline *status_line)
{
	free (status_line->first_line);
}

void
remove_newlines (char *s)
{
	char *p;

	for (p = s; *p != '\0'; p++)
		if (*p == '\r' || *p == '\n')
			*p = ' ';
}