48 lines
1.3 KiB
C
48 lines
1.3 KiB
C
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#include"util.h"
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// mman library to be used for hugepage allocations (e.g. mmap or posix_memalign only)
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#include <sys/mman.h>
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// [Bonus] TODO: define your own buffer size
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#define BUFF_SIZE (1<<21)
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//#define BUFF_SIZE TODO
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int main(int argc, char **argv)
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{
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// Allocate a buffer using huge page
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// See the handout for details about hugepage management
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void *buf= mmap(NULL, BUFF_SIZE, PROT_READ | PROT_WRITE, MAP_POPULATE |
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MAP_ANONYMOUS | MAP_PRIVATE | MAP_HUGETLB, -1, 0);
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if (buf == (void*) - 1) {
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perror("mmap() error\n");
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exit(EXIT_FAILURE);
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}
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// The first access to a page triggers overhead associated with
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// page allocation, TLB insertion, etc.
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// Thus, we use a dummy write here to trigger page allocation
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// so later access will not suffer from such overhead.
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*((char *)buf) = 1; // dummy write to trigger page allocation
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// [Bonus] TODO:
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// Put your covert channel setup code here
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printf("Please type a message.\n");
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bool sending = true;
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while (sending) {
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char text_buf[128];
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fgets(text_buf, sizeof(text_buf), stdin);
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// [Bonus] TODO:
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// Put your covert channel code here
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}
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printf("Sender finished.\n");
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return 0;
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}
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