/*************************************************************************
* (C) 2010 AITNET ltd - Sofia/Bulgaria - <misho@aitbg.com>
*  by Michael Pounov <misho@openbsd-bg.org>
*
* $Author: misho $
* $Id: srv.c,v 1.1 2010/06/18 01:48:06 misho Exp $
*
*************************************************************************/
#include "global.h"


static void *
rpc_srv_dispatchCall(void *arg)
{
	rpc_cli_t *c = arg;
	rpc_srv_t *s;
	rpc_val_t *vals, *v = NULL;
	rpc_func_t *f;
	struct tagRPCCall *rpc;
	struct tagRPCRet rrpc;
	fd_set fds;
	u_char buf[BUFSIZ], *data;
	int ret, argc, Limit = 0;
	register int i;

	if (!arg) {
		rpc_SetErr(EINVAL, "Error:: Invalid parameter can`t procced RPC client ...\n");
		return NULL;
	} else
		s = c->cli_parent;

	do {
		FD_ZERO(&fds);
		FD_SET(c->cli_sock, &fds);
		ret = select(c->cli_sock + 1, &fds, NULL, NULL, NULL);
		if (ret == -1) {
			ret = -2;
		}
		memset(&rrpc, 0, sizeof rrpc);
		memset(buf, 0, BUFSIZ);
		if ((ret = recv(c->cli_sock, buf, BUFSIZ, 0)) == -1) {
			LOGERR;
			ret = -3;
			break;
		}
		if (!ret) {		// receive EOF
			ret = 0;
			break;
		}
		if (ret < sizeof(struct tagRPCCall)) {
			rpc_SetErr(EMSGSIZE, "Error:: too short RPC packet ...\n");
			ret = -4;
			break;
		} else
			rpc = (struct tagRPCCall*) buf;
		// check RPC packet session info
		if (memcmp(&rpc->call_session, &s->srv_session, sizeof rpc->call_session)) {
			rpc_SetErr(EINVAL, "Error:: get invalid RPC session ...\n");
			ret = -5;
			break;
		}
		// RPC is OK! Go decapsulate variables ...
		if (rpc->call_argc) {
			v = (rpc_val_t*) (buf + sizeof(struct tagRPCCall));
			// RPC received variables types OK!
			data = (u_char*) v + rpc->call_argc * sizeof(rpc_val_t);
			for (i = 0; i < rpc->call_argc; i++) {
				switch (v[i].val_type) {
					case buffer:
						v[i].val.buffer = data;
					       	data += v[i].val_len;
						break;
					case string:
						v[i].val.string = (int8_t*) data;
						data += v[i].val_len + 1;
						break;
					case array:
						v[i].val.array = (int8_t**) data;
					       	data += v[i].val_len;
						break;
					default:
						break;
				}
			}
		}

		argc = 0;
		vals = NULL;
		if (!(f = rpc_srv_getCall(s, rpc->call_tag, rpc->call_hash))) {
			rpc_SetErr(EINVAL, "Error:: call not found into RPC server ...\n");
			ret = -6;
		} else
			if ((ret = rpc_srv_execCall(s, f, rpc, v)) == -1)
				ret = -6;
			else
				argc = rpc_srv_getValsCall(f, &vals);

		memcpy(&rrpc.ret_session, &rpc->call_session, sizeof rrpc.ret_session);
		rrpc.ret_tag = rpc->call_tag;
		rrpc.ret_hash = rpc->call_hash;
		rrpc.ret_errno = rpc_Errno;
		rrpc.ret_retcode = ret;
		rrpc.ret_argc = argc;

		memset(buf, 0, BUFSIZ);
		memcpy(buf, &rrpc, (Limit = sizeof rrpc));
		if (argc && vals) {
			v = (rpc_val_t*) (buf + sizeof rrpc);
			memcpy(v, vals, argc * sizeof(rpc_val_t));
			Limit += argc * sizeof(rpc_val_t);
			data = (u_char*) v + argc * sizeof(rpc_val_t);
			for (ret = i = 0; i < argc; i++) {
				switch (vals[i].val_type) {
					case buffer:
						if (ret || Limit + vals[i].val_len > BUFSIZ) {
							rpc_SetErr(EMSGSIZE, "Error:: in prepare RPC packet (-7) ...\n");
							rrpc.ret_retcode = ret = -7;
							rrpc.ret_argc = 0;
							break;
						}

						memcpy(data, vals[i].val.buffer, vals[i].val_len);
						data += vals[i].val_len;
						Limit += vals[i].val_len;
						break;
					case string:
						if (ret || Limit + vals[i].val_len + 1 > BUFSIZ) {
							rpc_SetErr(EMSGSIZE, "Error:: in prepare RPC packet (-7) ...\n");
							rrpc.ret_retcode = ret = -7;
							rrpc.ret_argc = 0;
							break;
						}

						memcpy(data, vals[i].val.string, vals[i].val_len + 1);
						data += vals[i].val_len + 1;
						Limit += vals[i].val_len + 1;
						break;
					case array:
						if (ret || Limit + vals[i].val_len > BUFSIZ) {
							rpc_SetErr(EMSGSIZE, "Error:: in prepare RPC packet (-7) ...\n");
							rrpc.ret_retcode = ret = -7;
							rrpc.ret_argc = 0;
							break;
						}

						memcpy(data, vals[i].val.array, vals[i].val_len);
						data += vals[i].val_len;
						Limit += vals[i].val_len;
						break;
					default:
						break;
				}

				RPC_FREE_VAL(&vals[i]);
			}
		}

		if ((ret = send(c->cli_sock, buf, Limit, 0)) == -1) {
			LOGERR;
			ret = -8;
			break;
		}
		if (ret != Limit) {
			rpc_SetErr(EBADMSG, "Error:: in send RPC request, should be send %d bytes, "
					"really is %d\n", Limit, ret);
			ret = -9;
			break;
		}
	} while (ret > -1);

	shutdown(c->cli_sock, SHUT_RDWR);
	close(c->cli_sock);
	memset(c, 0, sizeof(rpc_cli_t));
	return (void*) ret;
}

// -------------------------------------------------

/*
 * rpc_srv_initServer() Init & create RPC Server
 * @regProgID = ProgramID for authentication & recognition
 * @regProcID = ProcessID for authentication & recognition
 * @concurentClients = Concurent clients at same time to this server
 * @family = Family socket type, AF_INET or AF_INET6
 * @csHost = Host name or IP address for bind server, if NULL any address
 * @Port = Port for bind server, if Port == 0 default port is selected
 * return: NULL == error or !=NULL bind and created RPC server instance
 */
rpc_srv_t *
rpc_srv_initServer(u_int regProgID, u_int regProcID, int concurentClients, 
		u_short family, const char *csHost, u_short Port)
{
	rpc_srv_t *srv = NULL;
	int n = 1;
	struct hostent *host = NULL;
	struct sockaddr_in sin;
	struct sockaddr_in6 sin6;

	if (!concurentClients || !regProgID || (family != AF_INET && family != AF_INET6)) {
		rpc_SetErr(EINVAL, "Error:: Invalid parameters can`t init RPC server ...\n");
		return NULL;
	}
	if (!Port)
		Port = RPC_DEFPORT;
	if (csHost) {
		host = gethostbyname2(csHost, family);
		if (!host) {
			rpc_SetErr(h_errno, "Error:: %s\n", hstrerror(h_errno));
			return NULL;
		}
	}
	switch (family) {
		case AF_INET:
			memset(&sin, 0, sizeof sin);
			sin.sin_len = sizeof sin;
			sin.sin_family = family;
			sin.sin_port = htons(Port);
			if (csHost)
				memcpy(&sin.sin_addr, host->h_addr, host->h_length);
			break;
		case AF_INET6:
			memset(&sin6, 0, sizeof sin6);
			sin6.sin6_len = sizeof sin6;
			sin6.sin6_family = family;
			sin6.sin6_port = htons(Port);
			if (csHost)
				memcpy(&sin6.sin6_addr, host->h_addr, host->h_length);
			break;
		default:
			rpc_SetErr(EINVAL, "Error:: Invalid parameters can`t start RPC server ...\n");
			return NULL;
	}

	srv = malloc(sizeof(rpc_srv_t));
	if (!srv) {
		LOGERR;
		return NULL;
	} else
		memset(srv, 0, sizeof(rpc_srv_t));

	srv->srv_numcli = concurentClients;
	srv->srv_session.sess_version = RPC_VERSION;
	srv->srv_session.sess_program = regProgID;
	srv->srv_session.sess_process = regProcID;

	srv->srv_server.cli_parent = srv;
	if (family == AF_INET)
		memcpy(&srv->srv_server.cli_sa, &sin, sizeof srv->srv_server.cli_sa);
	else
		memcpy(&srv->srv_server.cli_sa, &sin6, sizeof srv->srv_server.cli_sa);
	srv->srv_server.cli_sock = socket(family, SOCK_STREAM, 0);
	if (srv->srv_server.cli_sock == -1) {
		LOGERR;
		free(srv);
		return NULL;
	}
	if (setsockopt(srv->srv_server.cli_sock, SOL_SOCKET, SO_REUSEADDR, &n, sizeof n) == -1) {
		LOGERR;
		close(srv->srv_server.cli_sock);
		free(srv);
		return NULL;
	}
	if (bind(srv->srv_server.cli_sock, &srv->srv_server.cli_sa, sizeof srv->srv_server.cli_sa) == -1) {
		LOGERR;
		close(srv->srv_server.cli_sock);
		free(srv);
		return NULL;
	}

	srv->srv_clients = calloc(srv->srv_numcli, sizeof(rpc_cli_t));
	if (!srv->srv_clients) {
		LOGERR;
		close(srv->srv_server.cli_sock);
		free(srv);
		return NULL;
	} else
		memset(srv->srv_clients, 0, srv->srv_numcli * sizeof(rpc_cli_t));

	rpc_srv_registerCall(srv, NULL, CALL_SRVCLIENTS, 0);
	rpc_srv_registerCall(srv, NULL, CALL_SRVCALLS, 0);
	rpc_srv_registerCall(srv, NULL, CALL_SRVSESSIONS, 0);
	return srv;
}

/*
 * rpc_srv_endServer() Destroy RPC server, close all opened sockets and free resources
 * @srv = RPC Server instance
 * return: none
 */
void
rpc_srv_endServer(rpc_srv_t * __restrict srv)
{
	rpc_cli_t *c;
	register int i;
	rpc_func_t *f;

	if (!srv) {
		rpc_SetErr(EINVAL, "Error:: Can`t destroy server because parameter is null!\n");
		return;
	}

	while ((f = srv->srv_funcs)) {
		srv->srv_funcs = f->func_next;
		free(f);
	}

	for (i = 0, c = srv->srv_clients; i < srv->srv_numcli && c; i++, c++)
		if (c->cli_sa.sa_family)
			shutdown(c->cli_sock, SHUT_RDWR);
	close(srv->srv_server.cli_sock);

	if (srv->srv_clients) {
		free(srv->srv_clients);
		srv->srv_numcli = 0;
	}

	free(srv);
	srv = NULL;
}

/*
 * rpc_srv_execServer() Execute Main server loop and wait for clients requests
 * @srv = RPC Server instance
 * return: -1 error or 0 ok, infinite loop ...
 */
int
rpc_srv_execServer(rpc_srv_t * __restrict srv)
{
	socklen_t salen = sizeof(struct sockaddr);
	register int i;
	rpc_cli_t *c;

	if (!srv) {
		rpc_SetErr(EINVAL, "Error:: Invalid parameter can`t start RPC server ...\n");
		return -1;
	}

	if (listen(srv->srv_server.cli_sock, SOMAXCONN) == -1) {
		LOGERR;
		return -1;
	}

	while (42) {
		for (c = srv->srv_clients, i = 0; i < srv->srv_numcli && c; i++, c++)
			if (!c->cli_sa.sa_family)
				break;
		if (c && c->cli_sa.sa_family && c->cli_parent) {
			usleep(1000000);
			continue;
		}
		c->cli_sock = accept(srv->srv_server.cli_sock, &c->cli_sa, &salen);
		if (c->cli_sock == -1) {
			printf("%s(%d): #%d - %s\n", __func__, __LINE__, errno, strerror(errno));
			LOGERR;
			continue;
		} else
			c->cli_parent = srv;

		if (pthread_create(&c->cli_tid, NULL, rpc_srv_dispatchCall, c)) {
			LOGERR;
			continue;
		}
	}

	/* not reached !!! */
	return 0;
}

// ---------------------------------------------------------

/*
 * rpc_srv_freeValsCall() Free return variables for RPC call
 * @call = RPC function call
 * return: none
 */
inline void
rpc_srv_freeValsCall(rpc_func_t * __restrict call)
{
	rpc_srv_declValsCall(call, 0);
}

/*
 * rpc_srv_declValsCall() Declare return variables for RPC call
 * @call = RPC function call
 * @return_vals = Number of return variables
 * return: -1 error, !=-1 ok
 */
inline int
rpc_srv_declValsCall(rpc_func_t * __restrict call, int return_vals)
{
	void *ptr;

	if (!call || return_vals < 0) {
		rpc_SetErr(EINVAL, "Error:: Invalid parameter can`t declare return variables for RPC call...\n");
		return -1;
	} else
		call->func_args = return_vals;

	if (!return_vals) {
		if (call->func_vals) {
			free(call->func_vals);
			call->func_vals = NULL;
		}
	} else {
		ptr = realloc(call->func_vals, return_vals * sizeof(rpc_val_t));
		if (!ptr) {
			LOGERR;
			return -1;
		} else
			call->func_vals = ptr;
	}

	return call->func_args;
}

/*
 * rpc_srv_delValsCall() Clean values from return variables of RPC call
 * @call = RPC function call
 * return: -1 error, !=-1 Returned number of cleaned RPC variables
 */
inline int
rpc_srv_delValsCall(rpc_func_t * __restrict call)
{
	if (!call) {
		rpc_SetErr(EINVAL, "Error:: Invalid parameter can`t delete return variables ...\n");
		return -1;
	}

	memset(call->func_vals, 0, call->func_args * sizeof(rpc_val_t));
	return call->func_args;
}

/*
 * rpc_srv_copyValsCall() Copy return variables for RPC call to new variable
 * @call = RPC function call
 * @newvals = New allocated variables array, must be free after use
 * return: -1 error, !=-1 Returned number of copied RPC variables
 */
inline int
rpc_srv_copyValsCall(rpc_func_t * __restrict call, rpc_val_t ** __restrict newvals)
{
	if (!call || !newvals) {
		rpc_SetErr(EINVAL, "Error:: Invalid parameter can`t copy return variables to new array\n");
		return -1;
	}

	*newvals = calloc(call->func_args, sizeof(rpc_val_t));
	if (!*newvals) {
		LOGERR;
		return -1;
	} else
		memcpy(*newvals, call->func_vals, call->func_args * sizeof(rpc_val_t));

	return call->func_args;
}

/*
 * rpc_srv_getValsCall() Get return variables for RPC call
 * @call = RPC function call
 * @vals = Returned variables, may be NULL
 * return: -1 error, !=-1 Number of returned variables
 */
inline int
rpc_srv_getValsCall(rpc_func_t * __restrict call, rpc_val_t ** __restrict vals)
{
	if (!call) {
		rpc_SetErr(EINVAL, "Error:: Invalid parameter can`t get return variables ...\n");
		return -1;
	}

	if (vals)
		*vals = call->func_vals;
	return call->func_args;
}

// ---------------------------------------------------------

/*
 * rpc_srv_registerCall() Register call to RPC server
 * @srv = RPC Server instance
 * @csModule = Module name, if NULL self binary
 * @csFunc = Function name
 * @args = Number of function arguments
 * return: -1 error or 0 register ok
 */
int
rpc_srv_registerCall(rpc_srv_t * __restrict srv, const char *csModule, const char *csFunc, u_char args)
{
	rpc_func_t *func;
	u_char str[MAXPATHLEN + UCHAR_MAX + 1];

	memset(str, 0, MAXPATHLEN + UCHAR_MAX + 1);
	if (!srv || !csFunc) {
		rpc_SetErr(EINVAL, "Error:: Invalid parameter can`t register function to RPC server ...\n");
		return -1;
	}
	if (!(func = malloc(sizeof(rpc_func_t)))) {
		LOGERR;
		return -1;
	} else {
		memset(func, 0, sizeof(rpc_func_t));
		strlcpy((char*) func->func_name, csFunc, UCHAR_MAX + 1);
	}
	if (csModule) {
		strlcpy((char*) func->func_file, csModule, MAXPATHLEN);
		strlcpy((char*) str, csModule, MAXPATHLEN + UCHAR_MAX + 1);
	}
	strlcat((char*) str, "__", MAXPATHLEN + UCHAR_MAX + 1);
	strlcat((char*) str, csFunc, MAXPATHLEN + UCHAR_MAX + 1);

	func->func_tag = crcFletcher16((u_short*) str, (MAXPATHLEN + UCHAR_MAX + 1) / 2);
	func->func_hash = hash_fnv((char*) str, MAXPATHLEN + UCHAR_MAX + 1);

	if (rpc_srv_declValsCall(func, args) == -1) {
		free(func);
		return -1;
	}

	func->func_next = srv->srv_funcs;
	srv->srv_funcs = func;
	return 0;
}

/*
 * rpc_srv_unregisterCall() Unregister call from RPC server
 * @srv = RPC Server instance
 * @csModule = Module name, if NULL self binary
 * @csFunc = Function name
 * return: -1 error, 0 not found call, 1 unregister ok
 */
int
rpc_srv_unregisterCall(rpc_srv_t * __restrict srv, const char *csModule, const char *csFunc)
{
	rpc_func_t func, *f, *curr;
	u_char str[MAXPATHLEN + UCHAR_MAX + 1];

	memset(&func, 0, sizeof(rpc_func_t));
	memset(str, 0, MAXPATHLEN + UCHAR_MAX + 1);
	if (!srv || !csFunc) {
		rpc_SetErr(EINVAL, "Error:: Invalid parameter can`t unregister function from RPC server ...\n");
		return -1;
	} else
		strlcpy((char*) func.func_name, csFunc, UCHAR_MAX + 1);
	if (csModule) {
		strlcpy((char*) func.func_file, csModule, MAXPATHLEN);
		strlcpy((char*) str, csModule, MAXPATHLEN + UCHAR_MAX + 1);
	}
	strlcat((char*) str, "__", MAXPATHLEN + UCHAR_MAX + 1);
	strlcat((char*) str, csFunc, MAXPATHLEN + UCHAR_MAX + 1);

	func.func_tag = crcFletcher16((u_short*) str, (MAXPATHLEN + UCHAR_MAX + 1) / 2);
	func.func_hash = hash_fnv((char*) str, MAXPATHLEN + UCHAR_MAX + 1);

	f = rpc_srv_getCall(srv, func.func_tag, func.func_hash);
	if (!f)		// not found element for unregister
		return 0;

	if (srv->srv_funcs == f) {	// if is 1st element
		srv->srv_funcs = srv->srv_funcs->func_next;

		if (f->func_args && f->func_vals)
			free(f->func_vals);
		free(f);
	} else {
		for (curr = srv->srv_funcs; curr->func_next != f; curr = curr->func_next);
		curr->func_next = curr->func_next->func_next;

		if (f->func_args && f->func_vals)
			free(f->func_vals);
		free(f);
	}

	return 1;
}

/*
 * rpc_srv_getCall() Get registered call from RPC server
 * @srv = RPC Server instance
 * @tag = tag for function
 * @hash = hash for function
 * return: NULL not found call, !=NULL return call
 */
inline rpc_func_t *
rpc_srv_getCall(rpc_srv_t * __restrict srv, uint16_t tag, uint32_t hash)
{
	rpc_func_t *f;

	if (!srv) {
		rpc_SetErr(EINVAL, "Error:: Invalid parameter can`t get function from RPC server ...\n");
		return NULL;
	}

	for (f = srv->srv_funcs; f; f = f->func_next)
		if (f->func_tag == tag && f->func_hash == hash)
			break;

	return f;
}

/*
 * rpc_srv_getFunc() Get registered call from RPC server by Name
 * @srv = RPC Server instance
 * @csModule = Module name, if NULL self binary
 * @csFunc = Function name
 * return: NULL not found call, !=NULL return call
 */
rpc_func_t *
rpc_srv_getFunc(rpc_srv_t * __restrict srv, const char *csModule, const char *csFunc)
{
	rpc_func_t func;
	u_char str[MAXPATHLEN + UCHAR_MAX + 1];

	memset(&func, 0, sizeof(rpc_func_t));
	memset(str, 0, MAXPATHLEN + UCHAR_MAX + 1);
	if (!srv || !csFunc) {
		rpc_SetErr(EINVAL, "Error:: Invalid parameter can`t get function from RPC server ...\n");
		return NULL;
	} else
		strlcpy((char*) func.func_name, csFunc, UCHAR_MAX + 1);
	if (csModule) {
		strlcpy((char*) func.func_file, csModule, MAXPATHLEN);
		strlcpy((char*) str, csModule, MAXPATHLEN + UCHAR_MAX + 1);
	}
	strlcat((char*) str, "__", MAXPATHLEN + UCHAR_MAX + 1);
	strlcat((char*) str, csFunc, MAXPATHLEN + UCHAR_MAX + 1);

	func.func_tag = crcFletcher16((u_short*) str, (MAXPATHLEN + UCHAR_MAX + 1) / 2);
	func.func_hash = hash_fnv((char*) str, MAXPATHLEN + UCHAR_MAX + 1);

	return rpc_srv_getCall(srv, func.func_tag, func.func_hash);
}

// ---------------------------------------------------------

/*
 * rpc_srv_execCall() Execute registered call from RPC server
 * @data = RPC const data
 * @call = Register RPC call
 * @rpc = IN RPC call structure
 * @args = IN RPC call array of rpc values
 * return: -1 error, !=-1 ok
 */
int
rpc_srv_execCall(void * const data, rpc_func_t * __restrict call, 
		struct tagRPCCall * __restrict rpc, rpc_val_t * __restrict args)
{
	void *dl;
	rpc_callback_t func;
	int ret;

	if (!data || !call || !rpc) {
		rpc_SetErr(EINVAL, "Error:: Invalid parameter can`t exec call from RPC server ...\n");
		return -1;
	}

	dl = dlopen((char*) (*call->func_file ? call->func_file : NULL), RTLD_NOW);
	if (!dl) {
		rpc_SetErr(ENOENT, "Error:: Can`t attach module %s!\n", dlerror());
		return -1;
	}

	func = dlsym(dl, (char*) call->func_name);
	if (func)
		ret = func(data, call, rpc->call_argc, args);
	else {
		rpc_SetErr(ENOEXEC, "Error:: Can`t find function %s!\n", dlerror());
		ret = -1;
	}

	dlclose(dl);
	return ret;
}