Initial import

COPYING

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+CC0 1.0 Universal
+
+Statement of Purpose
+
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Makefile

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+# discardd
+# Written in 2020 by Lucas
+# CC0 1.0 Universal/Public domain - No rights reserved
+#
+# To the extent possible under law, the author(s) have dedicated all
+# copyright and related and neighboring rights to this software to the
+# public domain worldwide. This software is distributed without any
+# warranty. You should have received a copy of the CC0 Public Domain
+# Dedication along with this software. If not, see
+# <http://creativecommons.org/publicdomain/zero/1.0/>.
+.POSIX:
+.SUFFIXES: .c
+
+P =	discardd
+V =	0.0
+
+PREFIX =	/usr/local
+
+BIN =	discardd
+SRC =	${BIN:=.c}
+FILES =	COPYING Makefile README ${SRC}
+
+.c:
+	${CC} ${CFLAGS} ${LDFLAGS} ${INCS} -o $@ $< ${LIBS}
+
+all: ${BIN}
+
+clean:
+	rm -f ${BIN} ${P}-${V}.tgz
+
+dist: clean
+	pax -ws ,^,${P}-${V}/, ${FILES} | gzip >${P}-${V}.tgz
+
+install: all
+	mkdir -p ${PREFIX}/bin
+	cp -f ${BIN} ${PREFIX}/bin
+	cd ${PREFIX}/bin && chmod 555 ${BIN}
+
+uninstall:
+	cd ${PREFIX}/bin && rm -f ${BIN}

README

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+discardd
+========
+
+This is a C implementation of the Discard Protocol, described in RFC
+863. The point of it is to kill boredness, get back to play a bit with
+network programming in C and to tackle how to use `poll(2)` to handle
+concurrent clients.
+
+`discardd` will listen on port 9999 if it's run as a normal user, and
+on port 9, reserved by IANA for it, if it's run as root.

discardd.c

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+/*
+ * discard
+ * Written in 2020 by Lucas
+ * CC0 1.0 Universal/Public domain - No rights reserved
+ *
+ * To the extent possible under law, the author(s) have dedicated all
+ * copyright and related and neighboring rights to this software to the
+ * public domain worldwide. This software is distributed without any
+ * warranty. You should have received a copy of the CC0 Public Domain
+ * Dedication along with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+#include <err.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+static void
+usage(void)
+{
+	fprintf(stderr, "Usage: %s -t | -u\n", getprogname());
+	exit(1);
+}
+
+int
+main(int argc, char *argv[])
+{
+	int ch, do_tcp, do_udp;
+
+	do_tcp = do_udp = 0;
+	while ((ch = getopt(argc, argv, "tu")) != -1) {
+		switch (ch) {
+		case 't':
+			do_tcp = 1;
+			break;
+		case 'u':
+			do_udp = 1;
+			break;
+		default:
+			usage();
+		}
+	}
+	argc -= optind;
+	argv += optind;
+
+	if (argc > 0)
+		usage();
+	if (!do_tcp && !do_udp)
+		errx(1, "one of -t or -u is needed");
+	if (do_tcp && do_udp)
+		errx(1, "-t and -u are mutually exclusive");
+	if (do_udp)
+		errx(1, "UDP unimplemented");
+	if (do_tcp)
+		errx(1, "TCP unimplemented");
+
+	return 0;
+}