commit 0b38c16e99e6f7c62fe275703ed16c3140ed6482
Author: hhvn <dev@hhvn.uk>
Date: Sat, 5 Jun 2021 18:59:55 +0100
makefile arg.h main.c: init basic server
Diffstat:
| A | arg.h | | | 70 | ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
| A | main.c | | | 177 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
| A | makefile | | | 12 | ++++++++++++ |
3 files changed, 259 insertions(+), 0 deletions(-)
diff --git a/arg.h b/arg.h
@@ -0,0 +1,70 @@
+/*
+ * Copy me if you can.
+ * by 20h
+ *
+ * 2012-2016 Christoph Lohmann <20h at r-36 dot net>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef ARG_H__
+#define ARG_H__
+
+extern char *argv0;
+
+/* use main(int argc, char *argv[]) */
+#define ARGBEGIN for (argv0 = *argv, argv++, argc--;\
+ argv[0] && argv[0][0] == '-'\
+ && argv[0][1];\
+ argc--, argv++) {\
+ char argc_;\
+ char **argv_;\
+ int brk_;\
+ if (argv[0][1] == '-' && argv[0][2] == '\0') {\
+ argv++;\
+ argc--;\
+ break;\
+ }\
+ int i_;\
+ for (i_ = 1, brk_ = 0, argv_ = argv;\
+ argv[0][i_] && !brk_;\
+ i_++) {\
+ if (argv_ != argv)\
+ break;\
+ argc_ = argv[0][i_];\
+ switch (argc_)
+
+#define ARGEND }\
+ }
+
+#define ARGC() argc_
+
+#define EARGF(x) ((argv[0][i_+1] == '\0' && argv[1] == NULL)?\
+ ((x), abort(), (char *)0) :\
+ (brk_ = 1, (argv[0][i_+1] != '\0')?\
+ (&argv[0][i_+1]) :\
+ (argc--, argv++, argv[0])))
+
+#define ARGF() ((argv[0][i_+1] == '\0' && argv[1] == NULL)?\
+ (char *)0 :\
+ (brk_ = 1, (argv[0][i_+1] != '\0')?\
+ (&argv[0][i_+1]) :\
+ (argc--, argv++, argv[0])))
+
+#endif
diff --git a/main.c b/main.c
@@ -0,0 +1,177 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <libgen.h>
+#include <stdarg.h>
+#include <netdb.h>
+#include <errno.h>
+#include <pwd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include "arg.h"
+
+#define EXIT_USAGE 2
+#define HOST_DFLT "localhost"
+#define PORT_DFLT "79"
+#define CQUEUE 255
+
+char *argv0;
+
+void
+usage(void) {
+ printf("usage: %s [-h host] [-p port]\n", basename(argv0));
+ exit(EXIT_USAGE);
+}
+
+int
+verbose(const char *format, ...) {
+ va_list ap;
+
+ va_start(ap, format);
+ vfprintf(stderr, format, ap);
+ va_end(ap);
+
+ return 1;
+}
+
+int
+error(const char *format, ...) {
+ va_list ap;
+
+ va_start(ap, format);
+ fprintf(stderr, "Error: ");
+ vfprintf(stderr, format, ap);
+ va_end(ap);
+
+ return 1;
+}
+
+int
+die(const int exitc, const char *format, ...) {
+ va_list ap;
+
+ va_start(ap, format);
+ fprintf(stderr, "Fatal: ");
+ vfprintf(stderr, format, ap);
+ va_end(ap);
+
+ exit(exitc);
+}
+
+int
+getsock(struct addrinfo *hints, char *host, char *port) {
+ struct addrinfo *ai;
+ int sret, sockopt;
+ int fd;
+
+ if ((sret = getaddrinfo(host, port, hints, &ai)) != 0 || ai == NULL)
+ die(1, "getaddrinfo() for %s:%s, %s\n", host, port, gai_strerror(sret));
+
+ fd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
+ sockopt = 1;
+ if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (int*)&sockopt, sizeof(int)) == -1)
+ die(1, "setsockopt(): %s\n", strerror(errno));
+ if (bind(fd, ai->ai_addr, ai->ai_addrlen) == -1)
+ die(1, "bind(): %s\n", strerror(errno));
+ if (listen(fd, CQUEUE) == -1)
+ die(1, "listen(): %s\n", strerror(errno));
+ verbose("Listening on port %s with fd %d\n", port, fd);
+
+ freeaddrinfo(ai);
+
+ return fd;
+}
+
+int
+read_line(int fd, char *dest, size_t len) {
+ size_t i = 0;
+ char c = 0;
+
+ do {
+ if (read(fd, &c, sizeof(char)) != sizeof(char))
+ return 0;
+ if (c != '\r')
+ dest[i++] = c;
+ } while (c != '\n' && i < len);
+
+ dest[i-1] = '\0';
+ return 1;
+}
+
+void
+get_userlist(int fd) {
+ /* TODO */
+ return;
+}
+
+void
+get_plan(int fd, char *user) {
+ /* TODO */
+ return;
+}
+
+void
+handler(int fd) {
+ char user[1024];
+
+ read_line(fd, user, sizeof(user));
+
+ if (user[0] == '\0')
+ get_userlist(fd);
+ else
+ get_plan(fd, user);
+}
+
+int
+main(int argc, char *argv[]) {
+ struct sockaddr *addr;
+ struct addrinfo hints;
+ char *host = NULL,
+ *port = NULL;
+ int sock, handle;
+ int serrno;
+ pid_t pid;
+
+ ARGBEGIN {
+ case 'h':
+ host = EARGF(usage());
+ break;
+ case 'p':
+ port = EARGF(usage());
+ break;
+ } ARGEND;
+
+ if (host == NULL)
+ host = HOST_DFLT;
+ if (port == NULL)
+ port = PORT_DFLT;
+
+ memset(&hints, 0, sizeof(hints));
+ hints.ai_family = AF_INET;
+ hints.ai_flags = AI_PASSIVE;
+ hints.ai_socktype = SOCK_STREAM;
+ sock = getsock(&hints, host, port);
+
+ for (;;) {
+ if ((handle = accept(sock, addr, (socklen_t *)sizeof(struct sockaddr))) == -1)
+ die(1, "accept(): %s\n", strerror(errno));
+ verbose("Accepted client with handle %d\n", handle);
+
+ switch (pid = fork()) {
+ case -1:
+ error("fork(): %s\n", strerror(serrno));
+ shutdown(handle, SHUT_RDWR);
+ close(handle);
+ break;
+ case 0:
+ handler(handle);
+ shutdown(handle, SHUT_RDWR);
+ close(handle);
+ break;
+ default:
+ verbose("Forking handle %d to PID %d\n", handle, pid);
+ }
+ }
+ return 0;
+}
diff --git a/makefile b/makefile
@@ -0,0 +1,12 @@
+CC ?= cc
+OBJ = main.o
+BIN = hfingerd
+
+$(BIN): $(OBJ)
+ $(CC) -g $(CFLAGS) $(LDFLAGS) -o $@ $<
+
+.c.o:
+ $(CC) -g $(CFLAGS) $(LDFLAGS) -c $<
+
+clean:
+ rm $(BIN) $(OBJ)
