60 lines
No EOL
1.3 KiB
C
60 lines
No EOL
1.3 KiB
C
/** Wrapper utility to mark all sockets of a program
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*
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* Compile:
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* gcc -fPIC -c -o mark.o mark.c
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* gcc -shared -o mark.so mark.o -ldl
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*
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* Use:
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* LD_PRELOAD="./soft_atimes.so" command
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*
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* @author Steffen Vogel <post@steffenvogel.de>
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* @authir D.J. Capelis
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* @copyright 2014-2015, Steffen Vogel
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* @copyright 2007, Regents of the University of California
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* @license GPLv3
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*********************************************************************************/
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#define _GNU_SOURCE
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#include <stdio.h>
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#include <stdlib.h>
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#include <dlfcn.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#define DEF_MARK 0xCD
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typedef int (*socket_t)(int domain, int type, int protocol);
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static socket_t _socket;
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int socket(int domain, int type, int protocol)
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{
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if (!_socket)
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_socket = (socket_t) dlsym(RTLD_NEXT, "socket");
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int sd = _socket(domain, type, protocol);
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if (sd >= 0) {
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if (domain == AF_INET || domain == AF_INET6) {
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unsigned mark;
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char *endptr, *env = getenv("MARK");
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if (env != NULL) {
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mark = strtoul(env, &endptr, 0);
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if (env == endptr) /* skip if invalid mark given */
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return sd;
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}
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else
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mark = DEF_MARK;
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printf("mark: setting SO_MARK for fd=%u to %#x\n", sd, mark);
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setsockopt(sd, SOL_SOCKET, SO_MARK, &mark, sizeof(mark));
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}
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}
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return sd;
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} |