int main(int argc, char **argv)
{
struct hp_options opts = { 0 };
hotpatch_t *hp = NULL;
int rc = 0;
/* parse all arguments first */
if ((rc = parse_arguments(argc, argv, &opts)) != 0) {
return rc;
}
print_options(&opts);
/* break from execution whenever a step fails */
do {
uintptr_t ptr = 0;
hp = hotpatch_create(opts.pid, opts.verbose);
if (!hp) {
fprintf(stderr, "[%s:%d] Unable to create hotpatch for PID %d\n",
__func__, __LINE__, opts.pid);
rc = -1;
break;
}
if (opts.dryrun)
break;
if (opts.dll) {
uintptr_t dlres = 0;
uintptr_t symres = 0;
rc = hotpatch_inject_library(hp, opts.dll, opts.symbol, NULL, 0,
&dlres, &symres);
if (rc >=0) {
printf("Dll was injected at %p\n", (void *)dlres);
printf("Invocation of %s() returned %p\n",
(opts.symbol ? opts.symbol : "_init"),
(void *)symres);
}
} else {
/* handles the stripped apps as well */
if (opts.is__start) {
ptr = hotpatch_get_entry_point(hp);
} else {
ptr = hotpatch_read_symbol(hp, opts.symbol, NULL, NULL);
}
if (!ptr) {
printf("Symbol %s not found. Cannot proceed\n", opts.symbol);
break;
}
printf("Setting execution pointer to %s at 0x"LX"\n", opts.symbol, ptr);
rc = hotpatch_attach(hp);
if (rc < 0) {
printf("Failed to attach to process. Cannot proceed\n");
break;
}
rc = hotpatch_exec_symbol(hp, ptr, opts.verbose);
if (rc < 0) {
printf("Failed to execute the symbol in 0x"LX"\n", ptr);
rc = hotpatch_detach(hp);
break;
}
rc = hotpatch_detach(hp);
}
} while (0);
hotpatch_destroy(hp);
hp = NULL;
if (opts.symbol)
free(opts.symbol);
opts.symbol = NULL;
if (opts.dll)
free(opts.dll);
opts.dll = NULL;
return rc;
}
hotpatch_t *hotpatch_create(pid_t pid, int verbose)
{
int rc = 0;
hotpatch_t *hp = NULL;
do {
char filename[OS_MAX_BUFFER];
if (pid <= 0) {
LOG_ERROR_INVALID_PID(pid);
break;
}
memset(filename, 0, sizeof(filename));
snprintf(filename, sizeof(filename), "/proc/%d/exe", pid);
if (verbose > 3)
fprintf(stderr, "[%s:%d] Exe symlink for pid %d : %s\n", __func__,
__LINE__, pid, filename);
hp = malloc(sizeof(*hp));
if (!hp) {
LOG_ERROR_OUT_OF_MEMORY;
rc = -1;
break;
}
memset(hp, 0, sizeof(*hp));
hp->verbose = verbose;
hp->pid = pid;
hp->is64 = HOTPATCH_EXE_IS_NEITHER;
hp->exe_symbols = exe_load_symbols(filename, hp->verbose,
&hp->exe_symbols_num,
&hp->exe_entry_point,
&hp->exe_interp,
&hp->is64);
if (!hp->exe_symbols) {
fprintf(stderr, "[%s:%d] Unable to find any symbols in exe.\n",
__func__, __LINE__);
rc = -1;
break;
}
if (hp->exe_entry_point == 0) {
fprintf(stderr, "[%s:%d] Entry point is 0. Invalid.\n",
__func__, __LINE__);
rc = -1;
break;
}
LOG_INFO_HEADERS_LOADED(verbose);
hp->ld_maps = ld_load_maps(hp->pid, hp->verbose, &hp->ld_maps_num);
if (!hp->ld_maps) {
fprintf(stderr, "[%s:%d] Unable to load data in "
"/proc/%d/maps.\n", __func__, __LINE__, pid);
rc = -1;
break;
}
if (verbose > 2)
fprintf(stderr, "[%s:%d] /proc/%d/maps loaded.\n",
__func__, __LINE__, pid);
if (hp->exe_symbols && hp->exe_symbols_num > 0) {
qsort(hp->exe_symbols, hp->exe_symbols_num,
sizeof(*hp->exe_symbols), elf_symbol_cmpqsort);
}
if (hotpatch_gather_functions(hp) < 0) {
fprintf(stderr, "[%s:%d] Unable to find all the functions"
" needed. Cannot proceed.\n", __func__, __LINE__);
rc = -1;
break;
}
if (rc < 0) {
hotpatch_destroy(hp);
hp = NULL;
}
} while (0);
return hp;
}