ca2749e1bd
In practical terms, passt doesn't benefit from the additional protection offered by the AGPL over the GPL, because it's not suitable to be executed over a computer network. Further, restricting the distribution under the version 3 of the GPL wouldn't provide any practical advantage either, as long as the passt codebase is concerned, and might cause unnecessary compatibility dilemmas. Change licensing terms to the GNU General Public License Version 2, or any later version, with written permission from all current and past contributors, namely: myself, David Gibson, Laine Stump, Andrea Bolognani, Paul Holzinger, Richard W.M. Jones, Chris Kuhn, Florian Weimer, Giuseppe Scrivano, Stefan Hajnoczi, and Vasiliy Ulyanov. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
139 lines
3 KiB
C
139 lines
3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* nsholder - maintain a namespace to be entered by other processes
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*
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* Copyright Red Hat
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* Author: David Gibson <david@gibson.dropbear.id.au>
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*
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* Can run in 3 modes:
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*
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* nsholder <path> hold
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* Designed to be run inside a namespace, opens a Unix domain
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* control socket at <path> and waits until instructed to stop
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* with "nsholder <path> stop"
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* nsholder <path> pid
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* Prints the PID of the nsholder hold process with control
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* socket <path>. This is given in the PID namespace where
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* nsholder pid is executed, not the one where nsholder hold is
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* running
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* nsholder <path> stop
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* Instruct the nsholder hold with control socket at <path> to exit.
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*/
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#define _GNU_SOURCE
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <errno.h>
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#include <unistd.h>
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#include <sys/socket.h>
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#include <linux/un.h>
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#define die(...) \
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do { \
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fprintf(stderr, __VA_ARGS__); \
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exit(1); \
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} while (0)
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static void usage(void)
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{
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die("Usage: holder <socket path> hold|pid\n");
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}
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static void hold(int fd, const struct sockaddr_un *addr)
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{
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int rc;
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rc = bind(fd, (struct sockaddr *)addr, sizeof(*addr));
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if (rc < 0)
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die("bind(): %s\n", strerror(errno));
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rc = listen(fd, 0);
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if (rc < 0)
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die("listen(): %s\n", strerror(errno));
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printf("nsholder: local PID=%d local UID=%u local GID=%u\n",
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getpid(), getuid(), getgid());
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do {
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int afd = accept(fd, NULL, NULL);
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char buf;
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if (afd < 0)
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die("accept(): %s\n", strerror(errno));
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rc = read(afd, &buf, sizeof(buf));
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if (rc < 0)
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die("read(): %s\n", strerror(errno));
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} while (rc == 0);
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unlink(addr->sun_path);
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}
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static void pid(int fd, const struct sockaddr_un *addr)
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{
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int rc;
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struct ucred peercred;
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socklen_t optlen = sizeof(peercred);
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do {
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rc = connect(fd, (struct sockaddr *)addr, sizeof(*addr));
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if (rc < 0 && errno != ENOENT && errno != ECONNREFUSED)
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die("connect(): %s\n", strerror(errno));
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} while (rc < 0);
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rc = getsockopt(fd, SOL_SOCKET, SO_PEERCRED,
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&peercred, &optlen);
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if (rc < 0)
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die("getsockopet(SO_PEERCRED): %s\n", strerror(errno));
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close(fd);
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printf("%d\n", peercred.pid);
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}
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static void stop(int fd, const struct sockaddr_un *addr)
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{
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int rc;
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char buf = 'Q';
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rc = connect(fd, (struct sockaddr *)addr, sizeof(*addr));
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if (rc < 0)
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die("connect(): %s\n", strerror(errno));
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rc = write(fd, &buf, sizeof(buf));
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if (rc < 0)
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die("write(): %s\n", strerror(errno));
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close(fd);
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}
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int main(int argc, char *argv[])
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{
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int fd;
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const char *sockname;
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struct sockaddr_un sockaddr = {
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.sun_family = AF_UNIX,
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};
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if (argc != 3)
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usage();
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sockname = argv[1];
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strncpy(sockaddr.sun_path, sockname, UNIX_PATH_MAX);
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fd = socket(AF_UNIX, SOCK_STREAM, PF_UNIX);
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if (fd < 0)
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die("socket(): %s\n", strerror(errno));
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if (strcmp(argv[2], "hold") == 0)
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hold(fd, &sockaddr);
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else if (strcmp(argv[2], "pid") == 0)
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pid(fd, &sockaddr);
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else if (strcmp(argv[2], "stop") == 0)
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stop(fd, &sockaddr);
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else
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usage();
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exit(0);
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}
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