test-librsloader.c revision 58ed8bce80acd10ea103dc9c94f83466fa500ac9
158ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien#include "librsloader.h" 258ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien 358ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien#include <assert.h> 458ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien#include <stdio.h> 558ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien#include <stdlib.h> 658ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien#include <string.h> 758ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien#include <time.h> 858ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien 958ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien#include <fcntl.h> 1058ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien#include <sys/mman.h> 1158ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien#include <sys/stat.h> 1258ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien#include <sys/types.h> 1358ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien#include <unistd.h> 1458ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien 1558ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chienstruct func_entry_t { 1658ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien char const *name; 1758ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien size_t name_len; 1858ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien void *addr; 1958ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien}; 2058ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien 2158ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chienvoid *find_sym(void *context, char const *name) { 2258ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien static struct func_entry_t const tab[] = { 2358ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien#define DEF(NAME, ADDR) \ 2458ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien { NAME, sizeof(NAME) - 1, (void *)(&(ADDR)) }, 2558ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien 2658ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien DEF("printf", printf) 2758ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien DEF("scanf", scanf) 2858ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien DEF("__isoc99_scanf", scanf) 2958ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien DEF("rand", rand) 3058ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien DEF("time", time) 3158ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien DEF("srand", srand) 3258ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien#undef DEF 3358ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien }; 3458ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien 3558ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien static size_t const tab_size = sizeof(tab) / sizeof(struct func_entry_t); 3658ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien 3758ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien // Note: Since our table is small, we are using trivial O(n) searching 3858ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien // function. For bigger table, it will be better to use binary 3958ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien // search or hash function. 4058ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien size_t i; 4158ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien size_t name_len = strlen(name); 4258ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien for (i = 0; i < tab_size; ++i) { 4358ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien if (name_len == tab[i].name_len && strcmp(name, tab[i].name) == 0) { 4458ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien return tab[i].addr; 4558ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien } 4658ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien } 4758ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien 4858ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien assert(0 && "Can't find symbol."); 4958ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien return 0; 5058ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien} 5158ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien 5258ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chienint main(int argc, char **argv) { 5358ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien if (argc < 2) { 5458ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien fprintf(stderr, "USAGE: %s [ELF] [ARGS]\n", argv[0]); 5558ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien exit(EXIT_FAILURE); 5658ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien } 5758ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien 5858ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien int fd = open(argv[1], O_RDONLY); 5958ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien if (fd < 0) { 6058ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien fprintf(stderr, "ERROR: Unable to open the file: %s\n", argv[1]); 6158ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien exit(EXIT_FAILURE); 6258ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien } 6358ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien 6458ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien struct stat sb; 6558ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien if (fstat(fd, &sb) != 0) { 6658ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien fprintf(stderr, "ERROR: Unable to stat the file: %s\n", argv[1]); 6758ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien close(fd); 6858ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien exit(EXIT_FAILURE); 6958ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien } 7058ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien 7158ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien unsigned char const *image = (unsigned char const *) 7258ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien mmap(NULL, sb.st_size, PROT_READ, MAP_PRIVATE, fd, 0); 7358ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien 7458ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien if (image == MAP_FAILED) { 7558ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien fprintf(stderr, "ERROR: Unable to mmap the file: %s\n", argv[1]); 7658ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien close(fd); 7758ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien exit(EXIT_FAILURE); 7858ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien } 7958ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien 8058ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien RSExecRef object = rsloaderCreateExec(image, sb.st_size, find_sym, 0); 8158ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien if (!object) { 8258ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien fprintf(stderr, "ERROR: Unable to load elf object.\n"); 8358ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien close(fd); 8458ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien exit(EXIT_FAILURE); 8558ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien } 8658ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien 8758ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien int (*main_stub)(int, char **) = 8858ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien (int (*)(int, char **))rsloaderGetSymbolAddress(object, "main"); 8958ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien 9058ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien int ret = main_stub(argc - 1, argv + 1); 9158ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien printf("============================================================\n"); 9258ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien printf("ELF object finished with code: %d\n", ret); 9358ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien fflush(stdout); 9458ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien 9558ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien rsloaderDisposeExec(object); 9658ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien 9758ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien close(fd); 9858ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien 9958ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien return EXIT_SUCCESS; 10058ed8bce80acd10ea103dc9c94f83466fa500ac9Logan Chien} 101