intercept chmod et al (4ebf4d77) · Commits · David Auer / gekkofs

ifs/include/preload/passthrough.hpp

+4 −0

Original line number	Diff line number	Diff line
		@@ -92,6 +92,10 @@ extern void* libc_fdopendir;
		extern void* libc_readdir;
		extern void* libc_closedir;

		extern void* libc_chmod;
		extern void* libc_fchmod;
		extern void* libc_fchmodat;

		extern void* libc_chdir;
		extern void* libc_fchdir;

ifs/src/preload/intcp_functions.cpp

+77 −0

Original line number	Diff line number	Diff line
		@@ -1206,6 +1206,83 @@ int intcp_closedir(DIR* dirp) {
		return LIBC_FUNC(closedir, dirp);
		}

		int chmod(const char *path, mode_t mode) {
		init_passthrough_if_needed();
		if(!CTX->initialized()) {
		return LIBC_FUNC(chmod, path, mode);
		}

		CTX->log()->trace("{}() called with path '{}'", __func__, path);
		std::string rel_path;
		if (!CTX->relativize_path(path, rel_path)) {
		return LIBC_FUNC(chmod, rel_path.c_str(), mode);
		}
		CTX->log()->warn("{}() operation not supported", __func__);
		errno = ENOTSUP;
		return -1;
		}

		int fchmod(int fd, mode_t mode) {
		init_passthrough_if_needed();
		if(CTX->initialized()) {
		CTX->log()->trace("{}() called [fd: {}, mode: {}]", __func__, fd, mode);
		if (CTX->file_map()->exist(fd)) {
		CTX->log()->warn("{}() operation not supported", __func__);
		errno = ENOTSUP;
		return -1;
		}
		}
		return LIBC_FUNC(fchmod, fd, mode);
		}

		int fchmodat(int dirfd, const char *cpath, mode_t mode, int flags) {
		init_passthrough_if_needed();
		if(!CTX->initialized()) {
		return LIBC_FUNC(fchmodat, dirfd, cpath, mode, flags);
		}

		if(cpath == nullptr \|\| cpath[0] == '\0') {
		CTX->log()->error("{}() path is invalid", __func__);
		errno = EINVAL;
		return -1;
		}

		CTX->log()->trace("{}() called path '{}', mode {}, dirfd {}, flags {}", __func__, cpath, mode, dirfd, flags);

		std::string resolved;

		if(cpath[0] != PSP) {
		if(!(CTX->file_map()->exist(dirfd))) {
		//TODO relative cpath could still lead to our FS
		return LIBC_FUNC(fchmodat, dirfd, cpath, mode, flags);
		}

		auto dir = CTX->file_map()->get_dir(dirfd);
		if(dir == nullptr) {
		CTX->log()->error("{}() dirfd is not a directory ", __func__);
		errno = ENOTDIR;
		return -1;
		}

		std::string path = CTX->mountdir();
		path.append(dir->path());
		path.push_back(PSP);
		path.append(cpath);
		if(resolve_path(path, resolved)) {
		CTX->log()->warn("{}() operation not supported", __func__);
		errno = ENOTSUP;
		return -1;
		}
		} else {
		if (CTX->relativize_path(cpath, resolved)) {
		CTX->log()->warn("{}() operation not supported", __func__);
		errno = ENOTSUP;
		return -1;
		}
		}
		return LIBC_FUNC(fchmodat, dirfd, resolved.c_str(), mode, flags);
		}

		int chdir(const char* path){
		init_passthrough_if_needed();
		if(!CTX->initialized()) {

ifs/src/preload/passthrough.cpp

+8 −0

Original line number	Diff line number	Diff line
		@@ -93,6 +93,10 @@ void* libc_fdopendir;
		void* libc_readdir;
		void* libc_closedir;

		void* libc_chmod;
		void* libc_fchmod;
		void* libc_fchmodat;

		void* libc_chdir;
		void* libc_fchdir;

		@@ -190,6 +194,10 @@ void init_passthrough_() {
		libc_readdir = dlsym(libc, "readdir");
		libc_closedir = dlsym(libc, "closedir");

		libc_chmod = dlsym(libc, "chmod");
		libc_fchmod = dlsym(libc, "fchmod");
		libc_fchmodat = dlsym(libc, "fchmodat");

		libc_chdir = dlsym(libc, "chdir");
		libc_fchdir = dlsym(libc, "fchdir");