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jsonbta/bta_json.c

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+/*
+ * bta_json.c - create socket and reply bta data
+ *
+ * Copyright 2013 Edward V. Emelianoff <eddy@sao.ru>
+ *
+ * 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 2 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#include <strings.h>
+#include "bta_json.h"
+
+// wait for child to avoid zombies
+static void wait_for_child(int sig){
+	pid_t child;
+	while((child = waitpid(-1, NULL, WNOHANG)) > 0);
+}
+
+// search a first word after needle without spaces
+char* stringscan(char *str, char *needle){
+	char *a, *e;
+	char *end = str + strlen(str);
+	a = strstr(str, needle);
+	if(!a) return NULL;
+	a += strlen(needle);
+	while (a < end && (*a == ' ' || *a == '\r' || *a == '\t' || *a == '\r')) a++;
+	if(a >= end) return NULL;
+	e = strchr(a, ' ');
+	if(e) *e = 0;
+	return a;
+}
+
+/**
+ * Parce data received from client
+ * In case of http request we send all avaiable data
+ * In case of request from client socket, parce it
+ * Socket's request have structure like "par1<del>par2<del>..."
+ * 		where "pars" are names of bta_pars fields
+ * 		<del> is delimeter: one of symbols " &\t\n"
+ * @param buf - incoming data
+ * @param L - length of buf
+ * @param par - returned parameters structure
+ */
+void parce_incoming_buf(char *buf, size_t L, bta_pars *par){
+	char *tok, *got;
+	memset(par, 0, sizeof(bta_pars));
+	DBG("got data: %s", buf);
+	// http request - send all if get == "bta_par"
+	// if get == "bta_par?a&b&c...", change buf to pars
+	if((got = stringscan(buf, "GET"))){
+		size_t LR = strlen(RESOURCE);
+		if(strcmp(got, RESOURCE) == 0){
+			par->ALL = true;
+			return;
+		}else if(strncmp(got, RESOURCE, LR) == 0) buf = &got[LR+1];
+		else exit(-1); // wrong request
+	}
+	// request from socket -> check all parameters
+	tok = strtok(buf, " &\t\n");
+	if(!tok) return;
+	do{
+		#define checkpar(val) if(strcasecmp(tok, val) == 0){par->val = true; continue;}
+		checkpar(vel);
+		checkpar(diff);
+		checkpar(corr);
+		checkpar(mtime);
+		checkpar(meteo);
+		checkpar(target);
+		checkpar(p2mode);
+		checkpar(eqcoor);
+		checkpar(telmode);
+		checkpar(sidtime);
+		checkpar(horcoor);
+		checkpar(valsens);
+		checkpar(telfocus);
+		#undef checkpar
+	}while((tok = strtok(NULL, " &\t\n")));
+}
+
+void handle(int newsock){
+	size_t buflen = 4095;
+	char buffer[buflen + 1];
+	bta_pars par;
+	do{
+		ssize_t readed = recv(newsock, buffer, buflen, 0);
+		if(readed < 1) break; // client closed or error
+		parce_incoming_buf(buffer, readed, &par);
+		#ifdef EBUG
+			#define checkpar(val) if(par.val){ fprintf(stderr, "par: %s\n", val); }
+			if(par.ALL){ fprintf(stderr, "par: ALL\n"); }
+			checkpar(vel);
+			checkpar(diff);
+			checkpar(corr);
+			checkpar(mtime);
+			checkpar(sidtime);
+			checkpar(meteo);
+			checkpar(target);
+			checkpar(p2mode);
+			checkpar(eqcoor);
+			checkpar(telmode);
+			checkpar(horcoor);
+			checkpar(valsens);
+			checkpar(telfocus);
+			#undef checkpar
+		#endif // EBUG
+		make_JSON(newsock, &par);
+	}while(!par.ALL);
+	close(newsock);
+}
+
+int main(int argc, char **argv){
+	int sock;
+	struct sigaction sa;
+	struct addrinfo hints, *res, *p;
+	int reuseaddr = 1;
+	check4running(argv, PIDFILE, NULL);
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_family = AF_INET;
+	hints.ai_socktype = SOCK_STREAM;
+	hints.ai_flags = AI_PASSIVE;
+	if(getaddrinfo(NULL, PORT, &hints, &res) != 0){
+		perror("getaddrinfo");
+		return 1;
+	}
+	struct sockaddr_in *ia = (struct sockaddr_in*)res->ai_addr;
+	char str[INET_ADDRSTRLEN];
+	inet_ntop(AF_INET, &(ia->sin_addr), str, INET_ADDRSTRLEN);
+	printf("port: %u, addr: %s\n", ntohs(ia->sin_port), str);
+	// loop through all the results and bind to the first we can
+	for(p = res; p != NULL; p = p->ai_next){
+		if((sock = socket(p->ai_family, p->ai_socktype, p->ai_protocol)) == -1){
+			perror("socket");
+			continue;
+		}
+		if(setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &reuseaddr, sizeof(int)) == -1){
+			perror("setsockopt");
+			return -1;
+		}
+		if(bind(sock, p->ai_addr, p->ai_addrlen) == -1){
+			close(sock);
+			perror("bind");
+			continue;
+		}
+		break; // if we get here, we must have connected successfully
+	}
+	if(p == NULL){
+		// looped off the end of the list with no successful bind
+		fprintf(stderr, "failed to bind socket\n");
+		exit(2);
+	}
+	// Listen
+	if(listen(sock, BACKLOG) == -1) {
+		perror("listen");
+		return 1;
+	}
+	freeaddrinfo(res);
+	// Set up the signal handler
+	sa.sa_handler = wait_for_child;
+	sigemptyset(&sa.sa_mask);
+	sa.sa_flags = SA_RESTART;
+	if (sigaction(SIGCHLD, &sa, NULL) == -1) {
+		perror("sigaction");
+		return 1;
+	}
+	// OK, all done, now we can daemonize
+	#ifndef EBUG // daemonize only in release mode
+		if(daemon(1, 0)){
+			perror("daemon()");
+			exit(1);
+		}
+	#endif // EBUG
+	// Main loop
+	while(1){
+		struct sockaddr_in their_addr;
+		socklen_t size = sizeof(struct sockaddr_in);
+		int newsock = accept(sock, (struct sockaddr*)&their_addr, &size);
+		int pid;
+		if(newsock == -1) return 0;
+		pid = fork();
+		if(pid == 0){
+			// Child process
+			close(sock);
+			handle(newsock);
+			return 0;
+		}else{
+			// Parent process
+			if(pid == -1) return 1;
+			else{
+				close(newsock);
+				DBG("Create child: %d", pid);
+			}
+		}
+	}
+	close(sock);
+	return 0;
+}
+
+
+// ËÏÎÅÃ ÆÁÊÌÁ