diff --git a/libknet/common.c b/libknet/common.c index eefa100c..4d104722 100644 --- a/libknet/common.c +++ b/libknet/common.c @@ -1,120 +1,130 @@ /* * Copyright (C) 2010-2017 Red Hat, Inc. All rights reserved. * * Author: Fabio M. Di Nitto * * This software licensed under GPL-2.0+, LGPL-2.0+ */ #include "config.h" #include #include #include #include #include #include #include #include #include #include #include "logging.h" #include "common.h" int _fdset_cloexec(int fd) { int fdflags; fdflags = fcntl(fd, F_GETFD, 0); if (fdflags < 0) return -1; fdflags |= FD_CLOEXEC; if (fcntl(fd, F_SETFD, fdflags) < 0) return -1; return 0; } int _fdset_nonblock(int fd) { int fdflags; fdflags = fcntl(fd, F_GETFL, 0); if (fdflags < 0) return -1; fdflags |= O_NONBLOCK; if (fcntl(fd, F_SETFL, fdflags) < 0) return -1; return 0; } void *open_lib(knet_handle_t knet_h, const char *libname, int extra_flags) { void *ret = NULL; char *error = NULL; char dir[MAXPATHLEN], path[MAXPATHLEN], link[MAXPATHLEN]; struct stat sb; /* * clear any pending error */ dlerror(); ret = dlopen(libname, RTLD_NOW | RTLD_GLOBAL | extra_flags); error = dlerror(); if (error != NULL) { log_err(knet_h, KNET_SUB_COMMON, "unable to dlopen %s: %s", libname, error); errno = EAGAIN; return NULL; } memset(dir, 0, sizeof(dir)); memset(link, 0, sizeof(link)); memset(path, 0, sizeof(path)); if (dlinfo(ret, RTLD_DI_ORIGIN, &dir) < 0) { /* * should we dlclose and return error? */ log_warn(knet_h, KNET_SUB_COMMON, "unable to dlinfo %s: %s", libname, error); } else { snprintf(path, sizeof(path), "%s/%s", dir, libname); log_info(knet_h, KNET_SUB_COMMON, "%s has been loaded from %s", libname, path); /* * try to resolve the library and check if it is a symlink and to where. * we can't prevent symlink attacks but at least we can log where the library * has been loaded from */ if (lstat(path, &sb) < 0) { log_debug(knet_h, KNET_SUB_COMMON, "Unable to stat %s: %s", path, strerror(errno)); goto out; } if (S_ISLNK(sb.st_mode)) { if (readlink(path, link, sizeof(link)) < 0) { log_debug(knet_h, KNET_SUB_COMMON, "Unable to readlink %s: %s", path, strerror(errno)); goto out; } /* * symlink is relative to the directory */ if (link[0] != '/') { snprintf(path, sizeof(path), "%s/%s", dir, link); log_info(knet_h, KNET_SUB_COMMON, "%s/%s is a symlink to %s", dir, libname, path); } else { log_info(knet_h, KNET_SUB_COMMON, "%s/%s is a symlink to %s", dir, libname, link); } } } out: return ret; } + +void *remap_symbol(knet_handle_t knet_h, uint8_t subsystem, + void *lib_handle, const char *symbol_name) +{ + void *symbol = dlsym (lib_handle, symbol_name); + if (!symbol) { + log_err (knet_h, subsystem, "unable to map %s: %s", symbol_name, dlerror ()); + } + return symbol; +} diff --git a/libknet/common.h b/libknet/common.h index 6aebe630..f92f5941 100644 --- a/libknet/common.h +++ b/libknet/common.h @@ -1,19 +1,21 @@ /* * Copyright (C) 2012-2017 Red Hat, Inc. All rights reserved. * * Authors: Fabio M. Di Nitto * Federico Simoncelli * * This software licensed under GPL-2.0+, LGPL-2.0+ */ #include "internals.h" #ifndef __KNET_COMMON_H__ #define __KNET_COMMON_H__ int _fdset_cloexec(int fd); int _fdset_nonblock(int fd); void *open_lib(knet_handle_t knet_h, const char *libname, int extra_flags); +void *remap_symbol(knet_handle_t knet_h, uint8_t subsystem, + void *lib_handle, const char *symbol_name); #endif