diff options
Diffstat (limited to 'test')
| -rw-r--r-- | test/.gitignore | 1 | ||||
| -rw-r--r-- | test/Makefile | 8 | ||||
| -rw-r--r-- | test/nsholder.c | 139 |
3 files changed, 147 insertions, 1 deletions
diff --git a/test/.gitignore b/test/.gitignore index 129ddc0..d477a42 100644 --- a/test/.gitignore +++ b/test/.gitignore @@ -10,3 +10,4 @@ QEMU_EFI.fd *.start *.stop *.js +nsholder diff --git a/test/Makefile b/test/Makefile index f11c4b5..e0dc7ac 100644 --- a/test/Makefile +++ b/test/Makefile @@ -56,10 +56,13 @@ DOWNLOAD_ASSETS = mbuto \ $(DEBIAN_IMGS) $(FEDORA_IMGS) $(OPENSUSE_IMGS) $(UBUNTU_IMGS) LOCAL_ASSETS = mbuto.img QEMU_EFI.fd \ $(DEBIAN_IMGS:%=prepared-%) $(FEDORA_IMGS:%=prepared-%) \ - $(UBUNTU_NEW_IMGS:%=prepared-%) + $(UBUNTU_NEW_IMGS:%=prepared-%) \ + nsholder ASSETS = $(DOWNLOAD_ASSETS) $(LOCAL_ASSETS) +CFLAGS = -Wall -Werror + assets: $(ASSETS) mbuto: @@ -68,6 +71,9 @@ mbuto: mbuto.img: passt.mbuto mbuto ./mbuto/mbuto -p ./$< -c lz4 -f $@ +nsholder: nsholder.c + $(CC) $(CFLAGS) -o $@ $^ + QEMU_EFI.fd: ./find-arm64-firmware.sh $@ diff --git a/test/nsholder.c b/test/nsholder.c new file mode 100644 index 0000000..aac901b --- /dev/null +++ b/test/nsholder.c @@ -0,0 +1,139 @@ +// SPDX-License-Identifier: AGPL-3.0-or-later + +/* nsholder - maintain a namespace to be entered by other processes + * + * Copyright Red Hat + * Author: David Gibson <david@gibson.dropbear.id.au> + * + * Can run in 3 modes: + * + * nsholder <path> hold + * Designed to be run inside a namespace, opens a Unix domain + * control socket at <path> and waits until instructed to stop + * with "nsholder <path> stop" + * nsholder <path> pid + * Prints the PID of the nsholder hold process with control + * socket <path>. This is given in the PID namespace where + * nsholder pid is executed, not the one where nsholder hold is + * running + * nsholder <path> stop + * Instruct the nsholder hold with control socket at <path> to exit. + */ + +#define _GNU_SOURCE + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <unistd.h> +#include <sys/socket.h> +#include <linux/un.h> + +#define die(...) \ + do { \ + fprintf(stderr, __VA_ARGS__); \ + exit(1); \ + } while (0) + +static void usage(void) +{ + die("Usage: holder <socket path> hold|pid\n"); +} + +static void hold(int fd, const struct sockaddr_un *addr) +{ + int rc; + + rc = bind(fd, (struct sockaddr *)addr, sizeof(*addr)); + if (rc < 0) + die("bind(): %s\n", strerror(errno)); + + rc = listen(fd, 0); + if (rc < 0) + die("listen(): %s\n", strerror(errno)); + + printf("nsholder: local PID=%d local UID=%d local GID=%d\n", + getpid(), getuid(), getgid()); + do { + int afd = accept(fd, NULL, NULL); + char buf; + + if (afd < 0) + die("accept(): %s\n", strerror(errno)); + + rc = read(afd, &buf, sizeof(buf)); + if (rc < 0) + die("read(): %s\n", strerror(errno)); + } while (rc == 0); + + unlink(addr->sun_path); +} + +static void pid(int fd, const struct sockaddr_un *addr) +{ + int rc; + struct ucred peercred; + socklen_t optlen = sizeof(peercred); + + do { + rc = connect(fd, (struct sockaddr *)addr, sizeof(*addr)); + if (rc < 0 && errno != ENOENT && errno != ECONNREFUSED) + die("connect(): %s\n", strerror(errno)); + } while (rc < 0); + + rc = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, + &peercred, &optlen); + if (rc < 0) + die("getsockopet(SO_PEERCRED): %s\n", strerror(errno)); + + close(fd); + + printf("%d\n", peercred.pid); +} + +static void stop(int fd, const struct sockaddr_un *addr) +{ + int rc; + char buf = 'Q'; + + rc = connect(fd, (struct sockaddr *)addr, sizeof(*addr)); + if (rc < 0) + die("connect(): %s\n", strerror(errno)); + + rc = write(fd, &buf, sizeof(buf)); + if (rc < 0) + die("write(): %s\n", strerror(errno)); + + close(fd); +} + +int main(int argc, char *argv[]) +{ + int fd; + const char *sockname; + struct sockaddr_un sockaddr = { + .sun_family = AF_UNIX, + }; + + if (argc != 3) + usage(); + + sockname = argv[1]; + strncpy(sockaddr.sun_path, sockname, UNIX_PATH_MAX); + + fd = socket(AF_UNIX, SOCK_STREAM, PF_UNIX); + if (fd < 0) + die("socket(): %s\n", strerror(errno)); + + if (strcmp(argv[2], "hold") == 0) + hold(fd, &sockaddr); + else if (strcmp(argv[2], "pid") == 0) + pid(fd, &sockaddr); + else if (strcmp(argv[2], "stop") == 0) + stop(fd, &sockaddr); + else + usage(); + + exit(0); +} |