nuclear@0: #include <stdio.h>
nuclear@0: #include <stdlib.h>
nuclear@0: #include <string.h>
nuclear@0: #include <errno.h>
nuclear@0: #include <unistd.h>
nuclear@0: #include <fcntl.h>
nuclear@0: #include <sys/select.h>
nuclear@0: #include <sys/types.h>
nuclear@0: #include <sys/socket.h>
nuclear@0: #include <arpa/inet.h>
nuclear@0: 
nuclear@0: struct client {
nuclear@0: 	int s;
nuclear@0: 	char *rcvbuf;
nuclear@0: 	int bufsz;
nuclear@0: 	struct client *next;
nuclear@0: };
nuclear@0: 
nuclear@0: int start_server(void);
nuclear@0: int accept_conn(int lis);
nuclear@0: int handle_client(struct client *c);
nuclear@0: 
nuclear@0: static int lis;
nuclear@0: static int port = 8080;
nuclear@0: static struct client *clist;
nuclear@0: 
nuclear@0: int main(int argc, char **argv)
nuclear@0: {
nuclear@0: 	if((lis = start_server()) == -1) {
nuclear@0: 		return 1;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	for(;;) {
nuclear@0: 		struct client *c, dummy;
nuclear@0: 		int maxfd = lis;
nuclear@0: 		fd_set rdset;
nuclear@0: 
nuclear@0: 		FD_ZERO(&rdset);
nuclear@0: 		FD_SET(lis, &rdset);
nuclear@0: 
nuclear@0: 		c = clist;
nuclear@0: 		while(c) {
nuclear@0: 			if(c->s > maxfd) {
nuclear@0: 				maxfd = c->s;
nuclear@0: 			}
nuclear@0: 			FD_SET(c->s, &rdset);
nuclear@0: 			c = c->next;
nuclear@0: 		}
nuclear@0: 
nuclear@0: 		while(select(maxfd + 1, &rdset, 0, 0, 0) == -1 && errno == EINTR);
nuclear@0: 
nuclear@0: 		c = clist;
nuclear@0: 		while(c) {
nuclear@0: 			if(FD_ISSET(c->s, &rdset)) {
nuclear@0: 				handle_client(c);
nuclear@0: 			}
nuclear@0: 			c = c->next;
nuclear@0: 		}
nuclear@0: 
nuclear@0: 		if(FD_ISSET(lis, &rdset)) {
nuclear@0: 			accept_conn(lis);
nuclear@0: 		}
nuclear@0: 
nuclear@0: 		dummy.next = clist;
nuclear@0: 		c = &dummy;
nuclear@0: 
nuclear@0: 		while(c->next) {
nuclear@0: 			struct client *n = c->next;
nuclear@0: 
nuclear@0: 			if(n->s == -1) {
nuclear@0: 				/* marked for removal */
nuclear@0: 				c->next = n->next;
nuclear@0: 				free(n);
nuclear@0: 			} else {
nuclear@0: 				c = c->next;
nuclear@0: 			}
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: }
nuclear@0: 
nuclear@0: int start_server(void)
nuclear@0: {
nuclear@0: 	int s;
nuclear@0: 	struct sockaddr_in sa;
nuclear@0: 
nuclear@0: 	if((s = socket(PF_INET, SOCK_STREAM, 0)) == -1) {
nuclear@0: 		perror("failed to create listening socket");
nuclear@0: 		return -1;
nuclear@0: 	}
nuclear@0: 	fcntl(s, F_SETFL, fcntl(s, F_GETFL) | O_NONBLOCK);
nuclear@0: 
nuclear@0: 	memset(&sa, 0, sizeof sa);
nuclear@0: 	sa.sin_family = AF_INET;
nuclear@0: 	sa.sin_addr.s_addr = INADDR_ANY;
nuclear@0: 	sa.sin_port = htons(port);
nuclear@0: 
nuclear@0: 	if(bind(s, (struct sockaddr*)&sa, sizeof sa) == -1) {
nuclear@0: 		fprintf(stderr, "failed to bind socket to port %d: %s\n", port, strerror(errno));
nuclear@0: 		return -1;
nuclear@0: 	}
nuclear@0: 	listen(s, 16);
nuclear@0: 
nuclear@0: 	return s;
nuclear@0: }
nuclear@0: 
nuclear@0: int accept_conn(int lis)
nuclear@0: {
nuclear@0: 	int s;
nuclear@0: 	struct client *c;
nuclear@0: 	struct sockaddr_in addr;
nuclear@0: 	socklen_t addr_sz = sizeof addr;
nuclear@0: 
nuclear@0: 	if((s = accept(lis, (struct sockaddr*)&addr, &addr_sz)) == -1) {
nuclear@0: 		perror("failed to accept incoming connection");
nuclear@0: 		return -1;
nuclear@0: 	}
nuclear@0: 	fcntl(s, F_SETFL, fcntl(s, F_GETFL) | O_NONBLOCK);
nuclear@0: 
nuclear@0: 	if(!(c = malloc(sizeof *c))) {
nuclear@0: 		perror("failed to allocate memory while accepting connection");
nuclear@0: 		return -1;
nuclear@0: 	}
nuclear@0: 	c->s = s;
nuclear@0: 	c->rcvbuf = 0;
nuclear@0: 	c->bufsz = 0;
nuclear@0: 	c->next = clist;
nuclear@0: 	clist = c;
nuclear@0: 	return 0;
nuclear@0: }
nuclear@0: 
nuclear@0: int handle_client(struct client *c)
nuclear@0: {
nuclear@0: 	static char buf[2048];
nuclear@0: 	int rdsz;
nuclear@0: 
nuclear@0: 	while((rdsz = recv(c->s, buf, sizeof buf, 0)) > 0) {
nuclear@0: 		if(c->rcvbuf) {
nuclear@0: 			int newsz = c->bufsz + rdsz;
nuclear@0: 			char *newbuf = realloc(buf, newsz);
nuclear@0: 			if(!newbuf) {
nuclear@0: 				fprintf(stderr, "failed to allocate %d byte buffer\n", newsz);
nuclear@0: 				/* TODO http error */
nuclear@0: 				goto drop;
nuclear@0: 			}
nuclear@0: 
nuclear@0: 			memcpy(newbuf + c->bufsz, buf, rdsz);
nuclear@0: 
nuclear@0: 			c->rcvbuf = newbuf;
nuclear@0: 			c->bufsz = newsz;
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	/* TODO: parse header, drop on invalid, determine if the request
nuclear@0: 	 * is complete and process
nuclear@0: 	 */
nuclear@0: 
nuclear@0: 	if(rdsz == -1 && errno != EAGAIN) {
nuclear@0: drop:
nuclear@0: 		close(c->s);
nuclear@0: 		c->s = -1;
nuclear@0: 		free(c->rcvbuf);
nuclear@0: 	}
nuclear@0: 	return 0;
nuclear@0: }