nuclear@0: #include <stdio.h>
nuclear@0: #include <stdlib.h>
nuclear@0: #include <string.h>
nuclear@3: #include <ctype.h>
nuclear@3: #include <signal.h>
nuclear@0: #include <errno.h>
nuclear@0: #include <unistd.h>
nuclear@0: #include <fcntl.h>
nuclear@5: #include <sys/stat.h>
nuclear@0: #include <sys/select.h>
nuclear@5: #include <sys/mman.h>
nuclear@0: #include <sys/types.h>
nuclear@0: #include <sys/socket.h>
nuclear@0: #include <arpa/inet.h>
nuclear@1: #include "http.h"
nuclear@5: #include "mime.h"
nuclear@1: 
nuclear@1: /* HTTP version */
nuclear@1: #define HTTP_VER_MAJOR	1
nuclear@1: #define HTTP_VER_MINOR	1
nuclear@1: #define HTTP_VER_STR	"1.1"
nuclear@1: 
nuclear@1: /* maximum request length: 64mb */
nuclear@1: #define MAX_REQ_LENGTH	(65536 * 1024)
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@3: void close_conn(struct client *c);
nuclear@0: int handle_client(struct client *c);
nuclear@5: int do_get(struct client *c, const char *uri, int with_body);
nuclear@1: void respond_error(struct client *c, int errcode);
nuclear@3: void sighandler(int s);
nuclear@1: int parse_args(int argc, char **argv);
nuclear@0: 
nuclear@0: static int lis;
nuclear@0: static int port = 8080;
nuclear@0: static struct client *clist;
nuclear@0: 
nuclear@5: static const char *indexfiles[] = {
nuclear@5: 	"index.cgi",
nuclear@5: 	"index.html",
nuclear@5: 	"index.htm",
nuclear@5: 	0
nuclear@5: };
nuclear@5: 
nuclear@5: 
nuclear@0: int main(int argc, char **argv)
nuclear@0: {
nuclear@1: 	if(parse_args(argc, argv) == -1) {
nuclear@1: 		return 1;
nuclear@1: 	}
nuclear@1: 
nuclear@3: 	signal(SIGINT, sighandler);
nuclear@3: 	signal(SIGTERM, sighandler);
nuclear@3: 	signal(SIGQUIT, sighandler);
nuclear@3: 
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@4: 		clist = dummy.next;
nuclear@0: 	}
nuclear@3: 
nuclear@3: 	return 0;	/* unreachable */
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@1: void close_conn(struct client *c)
nuclear@1: {
nuclear@1: 	close(c->s);
nuclear@1: 	c->s = -1;	/* mark it for removal */
nuclear@1: 	free(c->rcvbuf);
nuclear@1: }
nuclear@1: 
nuclear@0: int handle_client(struct client *c)
nuclear@0: {
nuclear@3: 	struct http_req_header hdr;
nuclear@0: 	static char buf[2048];
nuclear@3: 	int rdsz, status;
nuclear@0: 
nuclear@0: 	while((rdsz = recv(c->s, buf, sizeof buf, 0)) > 0) {
nuclear@4: 		char *newbuf;
nuclear@4: 		int newsz = c->bufsz + rdsz;
nuclear@4: 		if(newsz > MAX_REQ_LENGTH) {
nuclear@4: 			respond_error(c, 413);
nuclear@4: 			return -1;
nuclear@4: 		}
nuclear@1: 
nuclear@4: 		if(!(newbuf = realloc(c->rcvbuf, newsz + 1))) {
nuclear@4: 			fprintf(stderr, "failed to allocate %d byte buffer\n", newsz);
nuclear@4: 			respond_error(c, 503);
nuclear@4: 			return -1;
nuclear@4: 		}
nuclear@0: 
nuclear@4: 		memcpy(newbuf + c->bufsz, buf, rdsz);
nuclear@4: 		newbuf[newsz] = 0;
nuclear@0: 
nuclear@4: 		c->rcvbuf = newbuf;
nuclear@4: 		c->bufsz = newsz;
nuclear@0: 	}
nuclear@0: 
nuclear@3: 	if((status = http_parse_header(&hdr, c->rcvbuf, c->bufsz)) != HTTP_HDR_OK) {
nuclear@3: 		http_print_header(&hdr);
nuclear@3: 		switch(status) {
nuclear@3: 		case HTTP_HDR_INVALID:
nuclear@3: 			respond_error(c, 400);
nuclear@3: 			return -1;
nuclear@3: 
nuclear@3: 		case HTTP_HDR_NOMEM:
nuclear@3: 			respond_error(c, 503);
nuclear@3: 			return -1;
nuclear@3: 
nuclear@3: 		case HTTP_HDR_PARTIAL:
nuclear@3: 			return 0;	/* partial header, continue reading */
nuclear@3: 		}
nuclear@3: 	}
nuclear@3: 	http_print_header(&hdr);
nuclear@3: 
nuclear@3: 	/* we only support GET and HEAD at this point, so freak out on anything else */
nuclear@3: 	switch(hdr.method) {
nuclear@3: 	case HTTP_GET:
nuclear@5: 		do_get(c, hdr.uri, 1);
nuclear@5: 		break;
nuclear@5: 
nuclear@3: 	case HTTP_HEAD:
nuclear@5: 		do_get(c, hdr.uri, 0);
nuclear@3: 		break;
nuclear@3: 
nuclear@3: 	default:
nuclear@3: 		respond_error(c, 501);
nuclear@3: 		return -1;
nuclear@1: 	}
nuclear@1: 
nuclear@3: 	close_conn(c);
nuclear@3: 	return 0;
nuclear@3: }
nuclear@1: 
nuclear@5: int do_get(struct client *c, const char *uri, int with_body)
nuclear@3: {
nuclear@5: 	const char *ptr;
nuclear@5: 	struct http_resp_header resp;
nuclear@5: 
nuclear@5: 	if((ptr = strstr(uri, "://"))) {
nuclear@5: 		/* skip the host part */
nuclear@5: 		if(!(uri = strchr(ptr + 3, '/'))) {
nuclear@5: 			respond_error(c, 404);
nuclear@5: 			return -1;
nuclear@5: 		}
nuclear@5: 		++uri;
nuclear@5: 	}
nuclear@5: 
nuclear@5: 	if(*uri) {
nuclear@5: 		struct stat st;
nuclear@5: 		char *path = 0;
nuclear@5: 		char *buf;
nuclear@5: 		const char *type;
nuclear@5: 		int fd, size;
nuclear@5: 
nuclear@5: 		if(stat(uri, &st) == -1) {
nuclear@5: 			respond_error(c, 404);
nuclear@5: 			return -1;
nuclear@5: 		}
nuclear@5: 
nuclear@5: 		if(S_ISDIR(st.st_mode)) {
nuclear@5: 			int i;
nuclear@5: 			path = alloca(strlen(uri) + 64);
nuclear@5: 
nuclear@5: 			for(i=0; indexfiles[i]; i++) {
nuclear@5: 				sprintf(path, "%s/%s", uri, indexfiles[i]);
nuclear@5: 				if(stat(path, &st) == 0 && !S_ISDIR(st.st_mode)) {
nuclear@5: 					break;
nuclear@5: 				}
nuclear@5: 			}
nuclear@5: 
nuclear@5: 			if(indexfiles[i] == 0) {
nuclear@5: 				respond_error(c, 404);
nuclear@5: 				return -1;
nuclear@5: 			}
nuclear@5: 		} else {
nuclear@5: 			path = (char*)uri;
nuclear@5: 		}
nuclear@5: 
nuclear@5: 		if((fd = open(path, O_RDONLY)) == -1) {
nuclear@5: 			respond_error(c, 403);
nuclear@5: 			return -1;
nuclear@5: 		}
nuclear@5: 
nuclear@5: 		/* construct response header */
nuclear@5: 		http_init_resp(&resp);
nuclear@5: 		http_add_resp_field(&resp, "Content-Length: %d", st.st_size);
nuclear@5: 		if((type = mime_type(path))) {
nuclear@5: 			http_add_resp_field(&resp, "Content-Type: %s", type);
nuclear@5: 		}
nuclear@5: 
nuclear@5: 		size = http_serialize_resp(&resp, 0);
nuclear@5: 		buf = alloca(size);
nuclear@5: 		http_serialize_resp(&resp, buf);
nuclear@5: 		send(c->s, buf, size, 0);
nuclear@5: 
nuclear@5: 		if(with_body) {
nuclear@5: 			char *cont = mmap(0, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
nuclear@5: 			if(cont == (void*)-1) {
nuclear@5: 				respond_error(c, 503);
nuclear@5: 				close(fd);
nuclear@5: 				return -1;
nuclear@5: 			}
nuclear@5: 		}
nuclear@5: 
nuclear@5: 		close(fd);
nuclear@5: 	}
nuclear@5: 	return 0;
nuclear@1: }
nuclear@0: 
nuclear@1: void respond_error(struct client *c, int errcode)
nuclear@1: {
nuclear@1: 	char buf[512];
nuclear@1: 
nuclear@1: 	sprintf(buf, HTTP_VER_STR " %d %s\r\n\r\n", errcode, http_strmsg(errcode));
nuclear@1: 
nuclear@1: 	send(c->s, buf, strlen(buf), 0);
nuclear@1: 	close_conn(c);
nuclear@1: }
nuclear@1: 
nuclear@3: void sighandler(int s)
nuclear@3: {
nuclear@3: 	if(s == SIGINT || s == SIGTERM || s == SIGQUIT) {
nuclear@3: 		close(lis);
nuclear@3: 		while(clist) {
nuclear@3: 			struct client *c = clist;
nuclear@3: 			clist = clist->next;
nuclear@3: 			close_conn(c);
nuclear@3: 			free(c);
nuclear@3: 		}
nuclear@3: 		clist = 0;
nuclear@3: 
nuclear@3: 		printf("bye!\n");
nuclear@3: 		exit(0);
nuclear@3: 	}
nuclear@3: }
nuclear@3: 
nuclear@1: 
nuclear@1: static void print_help(const char *argv0)
nuclear@1: {
nuclear@1: 	printf("Usage: %s [options]\n", argv0);
nuclear@1: 	printf("Options:\n");
nuclear@1: 	printf(" -p <port>  set the TCP/IP port number to use\n");
nuclear@1: 	printf(" -h         print usage help and exit\n");
nuclear@1: }
nuclear@1: 
nuclear@1: int parse_args(int argc, char **argv)
nuclear@1: {
nuclear@1: 	int i;
nuclear@1: 
nuclear@1: 	for(i=1; i<argc; i++) {
nuclear@1: 		if(argv[i][0] == '-' && argv[i][2] == 0) {
nuclear@1: 			switch(argv[i][1]) {
nuclear@1: 			case 'p':
nuclear@1: 				if((port = atoi(argv[++i])) == 0) {
nuclear@1: 					fprintf(stderr, "-p must be followed by a valid port number\n");
nuclear@1: 					return -1;
nuclear@1: 				}
nuclear@1: 				break;
nuclear@1: 
nuclear@1: 			case 'h':
nuclear@1: 				print_help(argv[0]);
nuclear@1: 				exit(0);
nuclear@1: 
nuclear@1: 			default:
nuclear@1: 				fprintf(stderr, "unrecognized option: %s\n", argv[i]);
nuclear@1: 				return -1;
nuclear@1: 			}
nuclear@1: 		} else {
nuclear@1: 			fprintf(stderr, "unexpected argument: %s\n", argv[i]);
nuclear@1: 			return -1;
nuclear@1: 		}
nuclear@0: 	}
nuclear@0: 	return 0;
nuclear@0: }