response_phrase.c

#include <unistd.h>
#include "response_phrase.h"

static const char *informational_phrases[] = {
	/* 100 */ "Continue",
	/* 101 */ "Switching Protocols"
};

static const char *success_phrases[] = {
	/* 200 */ "OK",
	/* 201 */ "Created",
	/* 202 */ "Accepted",
	/* 203 */ "Non-Authoritative Information",
	/* 204 */ "No Content",
	/* 205 */ "Reset Content",
	/* 206 */ "Partial Content"
};

static const char *redirection_phrases[] = {
	/* 300 */ "Multiple Choices",
	/* 301 */ "Moved Permanently",
	/* 302 */ "Found",
	/* 303 */ "See Other",
	/* 304 */ "Not Modified",
	/* 305 */ "Use Proxy",
	/* 307 */ "Temporary Redirect"
};

static const char *client_error_phrases[] = {
	/* 400 */ "Bad Request",
	/* 401 */ "Unauthorized",
	/* 402 */ "Payment Required",
	/* 403 */ "Forbidden",
	/* 404 */ "Not Found",
	/* 405 */ "Method Not Allowed",
	/* 406 */ "Not Acceptable",
	/* 407 */ "Proxy Authentication Required",
	/* 408 */ "Request Time-out",
	/* 409 */ "Conflict",
	/* 410 */ "Gone",
	/* 411 */ "Length Required",
	/* 412 */ "Precondition Failed",
	/* 413 */ "Request Entity Too Large",
	/* 414 */ "Request-URI Too Large",
	/* 415 */ "Unsupported Media Type",
	/* 416 */ "Requested range not satisfiable",
	/* 417 */ "Expectation Failed"
};

static const char *server_error_phrases[] = {
	/* 500 */ "Internal Server Error",
	/* 501 */ "Not Implemented",
	/* 502 */ "Bad Gateway",
	/* 503 */ "Service Unavailable",
	/* 504 */ "Gateway Time-out",
	/* 505 */ "HTTP Version not supported"
};

struct response_class {
	const char *name;
	size_t num_responses;
	const char **responses;
};

#ifndef MEMBERSOF
#define MEMBERSOF(x) (sizeof(x)/sizeof(x[0]))
#endif

static const struct response_class response_classes[] = {
	/* 1xx */ { "Informational", MEMBERSOF(informational_phrases), informational_phrases },
	/* 2xx */ { "Success", MEMBERSOF(success_phrases), success_phrases },
	/* 3xx */ { "Redirection", MEMBERSOF(redirection_phrases), redirection_phrases },
	/* 4xx */ { "Client Error", MEMBERSOF(client_error_phrases), client_error_phrases },
	/* 5xx */ { "Server Error", MEMBERSOF(server_error_phrases), server_error_phrases }
};

const char *
http_response_phrase(int code)
{
	int klass = code / 100 - 1;
	int subcode = code % 100;

	/* Unknown class - can't do any better here */
	if (klass < 0 || klass >= (int) MEMBERSOF(response_classes))
		return "Unknown Status Class";

	/* Unknown sub-code, return class name at least */
	if (subcode >= (int) response_classes[klass].num_responses)
		return response_classes[klass].name;

	return response_classes[klass].responses[subcode];
}