make error

[blessendor]

Linux 4.4.134-1-pve #1 SMP PVE 4.4.134-112 (Thu, 05 Jul 2018 12:39:16 +0000) x86_64 GNU/Linux

~/eoip# make
cc -c -o eoip.o eoip.c -O3 -Wall
eoip.c: In function ‘setprocname’:
eoip.c:8:3: error: ‘for’ loop initial declarations are only allowed in C99 or C11 mode
for (int i = 0; environ[i]; i++) size += strlen(environ[i]) + 1;
^
eoip.c:8:3: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
eoip.c:11:12: error: redefinition of ‘i’
for (int i = 0; dst[i]; i++) size += strlen(dst[i]) + 1;
^
eoip.c:8:12: note: previous definition of ‘i’ was here
for (int i = 0; environ[i]; i++) size += strlen(environ[i]) + 1;
^
eoip.c:11:3: error: ‘for’ loop initial declarations are only allowed in C99 or C11 mode
for (int i = 0; dst[i]; i++) size += strlen(dst[i]) + 1;
^
eoip.c: In function ‘main’:
eoip.c:38:3: error: ‘for’ loop initial declarations are only allowed in C99 or C11 mode
for(int i = 1; i < argc; i++) {
^
Makefile:8: recipe for target 'eoip.o' failed
make: *** [eoip.o] Error 1

[magicnat]

Looks like your compiler default to C89/C90 standard. Adding -std=c99 to CFLAGS should fix this.

I've changed the CFLAGS in Makefile - you should be able to compile it now. Please pull the latest code and try again.

[blessendor]

I did some changes in the eoip.c and build was successful

#include "eoip.h"

// set name of the caller, inspired from nginx's ngx_setproctitle.c
void setprocname(char *name, char **dst) {
extern char **environ;

int i;

size_t size = 0;
for (i = 0; environ[i]; i++) size += strlen(environ[i]) + 1;
memset(environ, 0, size);
size = 0;

for (i = 0; dst[i]; i++) size += strlen(dst[i]) + 1;
memset(*dst, 0, size);

dst[1] = NULL;
strncpy(dst[0], name, strlen(name));
}

int main (int argc, char** argv) {
char src[INET6_ADDRSTRLEN], dst[INET6_ADDRSTRLEN], ifname[IFNAMSIZ];
unsigned int tid = 0, mtu = 1500, daemon = 0;
sa_family_t af = AF_INET;
in_port_t proto = PROTO_EOIP;
uid_t uid = 0;
gid_t gid = 0;
pid_t pid = 1;

if (argc < 2) {
fprintf(stderr, "Usage: eoip [ OPTIONS ] IFNAME { remote RADDR } { local LADDR } [ id TID ]\n");
fprintf(stderr, " [ mtu MTU ] [ uid UID ] [ gid GID ] [ fork ]\n");
fprintf(stderr, "where: OPTIONS := { -4 | -6 }\n");
exit(1);
}

// assume that the first argument is IFNAME
strncpy(ifname, argv[1], IFNAMSIZ);

// parse some args

int i;

for(i = 1; i < argc; i++) {
if(!strcmp(argv[i], "-4")) strncpy(ifname, argv[++i], IFNAMSIZ);
if(!strcmp(argv[i], "-6")) {
strncpy(ifname, argv[++i], IFNAMSIZ);
af = AF_INET6;
proto = PROTO_EOIP6;
}
if(!strcmp(argv[i], "id")) tid = atoi(argv[++i]);
if(!strcmp(argv[i], "local")) strncpy(src, argv[++i], INET6_ADDRSTRLEN);
if(!strcmp(argv[i], "remote")) strncpy(dst, argv[++i], INET6_ADDRSTRLEN);
if(!strcmp(argv[i], "mtu")) mtu = atoi(argv[++i]);
if(!strcmp(argv[i], "gid")) gid = atoi(argv[++i]);
if(!strcmp(argv[i], "uid")) uid = atoi(argv[++i]);
if(!strcmp(argv[i], "fork")) daemon = 1;
}

// fork to background?
if(daemon) {
pid = fork();
if(pid < 0) {
fprintf(stderr, "[ERR] can't daemonize: %s\n", strerror(errno));
exit(errno);
}
if(pid > 0) {
printf("%d\n", pid);
exit(0);
}
}

// build sockaddr for send/recv.
struct sockaddr_storage laddr, raddr;
socklen_t laddrlen, raddrlen;
populate_sockaddr(af, proto, src, &laddr, &laddrlen);
populate_sockaddr(af, proto, dst, &raddr, &raddrlen);

// bind a sock
int sock_fd;
if (bind_sock(&sock_fd, af, proto, (struct sockaddr*) &laddr, laddrlen) < 0) {
fprintf(stderr, "[ERR] can't bind socket: %s.\n", strerror(errno));
exit(errno);
}

// bind a tap interface
int tap_fd;
switch (make_tap(&tap_fd, ifname, mtu)) {
case 1:
fprintf(stderr, "[ERR] can't TUNSETIFF: %s.\n", strerror(errno));
exit(errno);
case 2:
fprintf(stderr, "[WARN] can't SIOCSIFMTU (%s), please set MTU manually.\n", strerror(errno));
case 3:
fprintf(stderr, "[WARN] running on OpenBSD/FreeBSD/Darwin, we can't set IFNAME, the interface will be: %s.\n", ifname);
default:
break;
}

// change UID/GID?
if (uid > 0 && setuid(uid)) {
fprintf(stderr, "[ERR] can't set UID: %s\n", strerror(errno));
exit(errno);
}
if (gid > 0 && setgid(gid)) {
fprintf(stderr, "[ERR] can't set GID: %s\n", strerror(errno));
exit(errno);
}

fprintf(stderr, "[INFO] attached to %s, mode %s, remote %s, local %s, tid %d, mtu %d.\n", ifname, af == AF_INET6 ? "EoIPv6" : "EoIP", dst, src, tid, mtu);

// all set, let's get to work.
pid_t writer = 1, sender = 1, dead;
int res, wdead = 0;
char procname[128];
snprintf(procname, 128, "eoip: master process (tunnel %d, dst %s, on %s)", tid, dst, ifname);
setprocname(procname, argv);

do {
if (writer == 1) writer = fork();
if (writer < 0) {
kill(-1, SIGTERM);
fprintf(stderr, "[ERR] faild to start TAP listener.\n");
exit(errno);
}
if (writer > 1 && !wdead) sender = fork();
if (sender < 0) {
kill(-1, SIGTERM);
fprintf(stderr, "[ERR] faild to start SOCK listener.\n");
exit(errno);
}
if (wdead) wdead = 0;
if (writer > 0 && sender > 0) {
dead = waitpid(-1, &res, 0);
if (dead == writer) writer = wdead = 1;
continue;
}
#if defined(linux)
prctl(PR_SET_PDEATHSIG, SIGTERM);
#endif
if (!sender) {
setprocname("eoip: TAP listener", argv);
tap_listen(af, tap_fd, sock_fd, tid, (struct sockaddr*) &raddr, raddrlen);
}
if (!writer) {
setprocname("eoip: SOCKS listener", argv);
sock_listen(af, sock_fd, tap_fd, tid, (struct sockaddr*) &raddr, raddrlen);
}
} while(1);
}

[blessendor]

BTW, tunnel with mikrotik not working

eoip -4 tap1 local 10.0.0.2 remote 10.0.0.1 id 100
ip link set tap1 up

[blessendor]

Your fix still returns errors with make:

root@st:~/eoip# make
cc -c -o eoip.o eoip.c -std=c99 -O3 -Wall
In file included from eoip.h:24:0,
from eoip.c:1:
sock.h:13:13: error: field ‘ip’ has incomplete type
struct ip ip;
^
eoip.c: In function ‘main’:
eoip.c:22:61: error: ‘IFNAMSIZ’ undeclared (first use in this function)
char src[INET6_ADDRSTRLEN], dst[INET6_ADDRSTRLEN], ifname[IFNAMSIZ];
^
eoip.c:22:61: note: each undeclared identifier is reported only once for each function it appears in
eoip.c:122:7: warning: implicit declaration of function ‘kill’ [-Wimplicit-function-declaration]
kill(-1, SIGTERM);
^
eoip.c:22:54: warning: unused variable ‘ifname’ [-Wunused-variable]
char src[INET6_ADDRSTRLEN], dst[INET6_ADDRSTRLEN], ifname[IFNAMSIZ];
^
Makefile:8: recipe for target 'eoip.o' failed
make: *** [eoip.o] Error 1

[blessendor]

And with my variant of eoip.c (without -std=c99) it's OK:

root@st:~/eoip# make
cc -c -o eoip.o eoip.c -O3 -Wall
cc -c -o sock.o sock.c -O3 -Wall
cc -c -o tap.o tap.c -O3 -Wall
cc -c -o eoip-proto.o eoip-proto.c -O3 -Wall
cc -O3 -Wall -o eoip eoip.o sock.o tap.o eoip-proto.o

[magicnat]

BTW, tunnel with mikrotik not working

Could you provide more information about your tunneling setup? (e.g. Firewall rules, src/dst of the tunnel on MikroTik, etc.)

I was able to make tunneling with MikroTik works without problem. Here's my configuration:

eoip.c:22:61: error: ‘IFNAMSIZ’ undeclared (first use in this function)

Not sure why but your environment seems to be missing IFNAMSIZ constant, which is in net/if.h, a part of libc.

[magicnat]

Just found out that -std=c99 cause some weird behavior. Try using -std=gnu99 instead.

[blessendor]

Thanks, I'll try later and give feedback

[blessendor]

make is works with -std=gnu99, but eopi is not

MikroTik
http://take.ms/vDmC4

debian
http://take.ms/Chdql

I will try on the other Linux host later

[WenceyWang]

Linux cannot respond to MikroTik keep-alive packet by itself.

You can disable keepalive or try use https://github.com/Jamesits/linux-gre-keepalive