Flash the Chrome EC lightbar when pf blocks a packet
initial work
+173
+42
Makefile
+42
Makefile
···
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# vim:ts=8
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VERS := 1.0
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CC ?= cc
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CFLAGS ?= -O2 -Wall -Wunused -Wmissing-prototypes -Wstrict-prototypes
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PREFIX ?= /usr/local
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BINDIR ?= $(DESTDIR)$(PREFIX)/bin
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MANDIR ?= $(DESTDIR)$(PREFIX)/man/man1
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INSTALL_PROGRAM ?= install -s
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INSTALL_DATA ?= install
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LIBS += -lpcap
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PROG = pflightbar
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OBJS = pflightbar.o
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all: $(PROG)
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$(PROG): $(OBJS)
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$(CC) $(OBJS) $(LDPATH) $(LIBS) -o $@
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$(OBJS): *.c
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$(CC) $(CFLAGS) $(INCLUDES) -c $< -o $@
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install: all
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mkdir -p $(BINDIR)
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$(INSTALL_PROGRAM) $(PROG) $(BINDIR)
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clean:
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rm -f $(PROG) $(OBJS)
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release: all
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@mkdir $(PROG)-${VERS}
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@cp Makefile *.c $(PROG)-$(VERS)/
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@tar -czf ../$(PROG)-$(VERS).tar.gz $(PROG)-$(VERS)
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@rm -rf $(PROG)-$(VERS)/
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@echo "made release ${VERS}"
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.PHONY: all install clean
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pflightbar.c
+131
pflightbar.c
···
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/*
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* Copyright (c) 2016 joshua stein <jcs@jcs.org>
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#include <sys/ioctl.h>
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#include <sys/socket.h>
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#include <err.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <pcap.h>
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#include <pwd.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <time.h>
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#include <unistd.h>
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#ifdef __amd64__
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#include <machine/chromeecvar.h>
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#else
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#error "this requires amd64"
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#endif
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int chromeec;
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time_t last_flash;
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void chromeec_set_seq(int);
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void chromeec_load_program(void);
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void have_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
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int
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main(int argc, char **argv)
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{
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pcap_handler phandler = have_packet;
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pcap_t *hpcap;
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struct passwd *pw;
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char errbuf[PCAP_ERRBUF_SIZE];
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if ((pw = getpwnam("nobody")) == NULL)
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errx(1, "nobody?");
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endpwent();
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if ((hpcap = pcap_open_live("pflog0", 1, 1, 500, errbuf)) == NULL)
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errx(1, "failed pcap_open_live(pflog0): %s", errbuf);
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if (pcap_datalink(hpcap) != DLT_PFLOG)
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errx(1, "invalid datalink type");
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if (ioctl(pcap_fileno(hpcap), BIOCLOCK) < 0)
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err(1, "BIOCLOCK");
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if ((chromeec = open("/dev/chromeec", O_RDWR)) == -1)
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err(1, "open /dev/chromeec");
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if (chroot("/var/empty") != 0 || chdir("/") != 0)
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err(1, "suk");
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if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1 ||
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setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1)
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err(1, "setresgid/setresuid");
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chromeec_load_program();
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last_flash = time(NULL);
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while (1) {
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if (pcap_dispatch(hpcap, 1, phandler, NULL) < 0)
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errx(1, "%s", pcap_geterr(hpcap));
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}
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return (0);
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}
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void chromeec_set_seq(int param)
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{
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if (ioctl(chromeec, CHROMEEC_IOC_LIGHTBAR_SET_SEQ, ¶m) < 0)
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err(1, "ioctl");
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}
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void chromeec_load_program(void)
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{
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struct chromeec_lightbar_program p = { 0 };
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int i = 0;
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/* red */
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p.data[i++] = CHROMEEC_LIGHTBAR_OPCODE_SET_COLOR_SINGLE;
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p.data[i++] = 0xf4;
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p.data[i++] = 0xff;
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/* ramp as fast as possible */
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p.data[i++] = CHROMEEC_LIGHTBAR_OPCODE_SET_RAMP_DELAY;
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p.data[i++] = 0x00;
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p.data[i++] = 0x00;
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p.data[i++] = 0x00;
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p.data[i++] = 0x01;
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/* cycle once and end */
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p.data[i++] = CHROMEEC_LIGHTBAR_OPCODE_ON;
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p.data[i++] = CHROMEEC_LIGHTBAR_OPCODE_CYCLE_ONCE;
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p.data[i++] = CHROMEEC_LIGHTBAR_OPCODE_OFF;
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p.data[i++] = CHROMEEC_LIGHTBAR_OPCODE_HALT;
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p.size = i;
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/* if the ec happens to be in SEQ_STOP it won't respond, so force it
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* back into s0 */
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chromeec_set_seq(CHROMEEC_LIGHTBAR_SEQ_S0);
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if (ioctl(chromeec, CHROMEEC_IOC_LIGHTBAR_SET_PROGRAM, &p) < 0)
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err(1, "ioctl");
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}
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void
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have_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
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{
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if (time(NULL) - last_flash <= 0)
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return;
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last_flash = time(NULL);
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chromeec_set_seq(CHROMEEC_LIGHTBAR_SEQ_PROGRAM);
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}