52 lines
1.0 KiB
C
52 lines
1.0 KiB
C
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/*
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* gcc unlink_failure.c -o unlink_failure.so -shared -ldl
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* LD_PRELOAD=./unlink_failure.so FAILURE_PATH=/etc/shadow ./test /etc/shadow
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*/
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#define _GNU_SOURCE
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#include <dlfcn.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <stdarg.h>
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#include <fcntl.h>
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#include <string.h>
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#include <errno.h>
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#include <assert.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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typedef int (*unlink_type) (const char *path);
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static unlink_type next_unlink;
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static const char *failure_path = NULL;
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int unlink (const char *path)
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{
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if (NULL == next_unlink)
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{
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next_unlink = dlsym (RTLD_NEXT, "unlink");
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assert (NULL != next_unlink);
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}
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if (NULL == failure_path) {
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failure_path = getenv ("FAILURE_PATH");
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if (NULL == failure_path) {
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fputs ("No FAILURE_PATH defined\n", stderr);
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}
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}
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if ( (NULL != path)
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&& (NULL != failure_path)
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&& (strcmp (path, failure_path) == 0))
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{
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fprintf (stderr, "unlink FAILURE %s\n", path);
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errno = EBUSY;
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return -1;
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}
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return next_unlink (path);
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}
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