[mirror_lxcfs.git] / src / utils.c

/* SPDX-License-Identifier: LGPL-2.1+ */

#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif

#ifndef FUSE_USE_VERSION
#define FUSE_USE_VERSION 26
#endif

#define _FILE_OFFSET_BITS 64

#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <fuse.h>
#include <inttypes.h>
#include <sched.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/epoll.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>

#include "bindings.h"
#include "config.h"
#include "macro.h"
#include "memory_utils.h"
#include "utils.h"

/*
 * append the given formatted string to *src.
 * src: a pointer to a char* in which to append the formatted string.
 * sz: the number of characters printed so far, minus trailing \0.
 * asz: the allocated size so far
 * format: string format. See printf for details.
 * ...: varargs. See printf for details.
 */
/*
 * append the given formatted string to *src.
 * src: a pointer to a char* in which to append the formatted string.
 * sz: the number of characters printed so far, minus trailing \0.
 * asz: the allocated size so far
 * format: string format. See printf for details.
 * ...: varargs. See printf for details.
 */
char *must_strcat(char **src, size_t *sz, size_t *asz, const char *format, ...)
{
	char tmp[BUF_RESERVE_SIZE];
	va_list args;
	int tmplen;

	va_start (args, format);
	tmplen = vsnprintf(tmp, BUF_RESERVE_SIZE, format, args);
	va_end(args);

	if (!*src || tmplen + *sz + 1 >= *asz) {
		char *str;
		do {
			str = realloc(*src, *asz + BUF_RESERVE_SIZE);
		} while (!str);
		*src = str;
		*asz += BUF_RESERVE_SIZE;
	}
	memcpy((*src) +*sz , tmp, tmplen+1); /* include the \0 */
	*sz += tmplen;

	return *src;
}

/**
 * in_same_namespace - Check whether two processes are in the same namespace.
 * @pid1 - PID of the first process.
 * @pid2 - PID of the second process.
 * @ns   - Name of the namespace to check. Must correspond to one of the names
 *         for the namespaces as shown in /proc/<pid/ns/
 *
 * If the two processes are not in the same namespace returns an fd to the
 * namespace of the second process identified by @pid2. If the two processes are
 * in the same namespace returns -EINVAL, -1 if an error occurred.
 */
static int in_same_namespace(pid_t pid1, pid_t pid2, const char *ns)
{
	__do_close int ns_fd1 = -1, ns_fd2 = -1;
	int ret = -1;
	struct stat ns_st1, ns_st2;

	ns_fd1 = preserve_ns(pid1, ns);
	if (ns_fd1 < 0) {
		/* The kernel does not support this namespace. This is not an
		 * error.
		 */
		if (errno == ENOENT)
			return -EINVAL;

		return -1;
	}

	ns_fd2 = preserve_ns(pid2, ns);
	if (ns_fd2 < 0)
		return -1;

	ret = fstat(ns_fd1, &ns_st1);
	if (ret < 0)
		return -1;

	ret = fstat(ns_fd2, &ns_st2);
	if (ret < 0)
		return -1;

	/* processes are in the same namespace */
	if ((ns_st1.st_dev == ns_st2.st_dev) && (ns_st1.st_ino == ns_st2.st_ino))
		return -EINVAL;

	/* processes are in different namespaces */
	return move_fd(ns_fd2);
}

bool is_shared_pidns(pid_t pid)
{
	if (pid != 1)
		return false;

	if (in_same_namespace(pid, getpid(), "pid") == -EINVAL)
		return true;

	return false;
}

int preserve_ns(const int pid, const char *ns)
{
	int ret;
/* 5 /proc + 21 /int_as_str + 3 /ns + 20 /NS_NAME + 1 \0 */
#define __NS_PATH_LEN 50
	char path[__NS_PATH_LEN];

	/* This way we can use this function to also check whether namespaces
	 * are supported by the kernel by passing in the NULL or the empty
	 * string.
	 */
	ret = snprintf(path, __NS_PATH_LEN, "/proc/%d/ns%s%s", pid,
		       !ns || strcmp(ns, "") == 0 ? "" : "/",
		       !ns || strcmp(ns, "") == 0 ? "" : ns);
	if (ret < 0 || (size_t)ret >= __NS_PATH_LEN) {
		errno = EFBIG;
		return -1;
	}

	return open(path, O_RDONLY | O_CLOEXEC);
}

void do_release_file_info(struct fuse_file_info *fi)
{
	struct file_info *f;

	f = INTTYPE_TO_PTR(fi->fh);
	if (!f)
		return;

	fi->fh = 0;

	free_disarm(f->controller);
	free_disarm(f->cgroup);
	free_disarm(f->file);
	free_disarm(f->buf);
	free_disarm(f);
}

#define POLLIN_SET ( EPOLLIN | EPOLLHUP | EPOLLRDHUP )

bool wait_for_sock(int sock, int timeout)
{
	__do_close int epfd = -EBADF;
	struct epoll_event ev;
	int ret, now, starttime, deltatime;

	if ((starttime = time(NULL)) < 0)
		return false;

	epfd = epoll_create(1);
	if (epfd < 0)
		return log_error(false, "%s\n", "Failed to create epoll socket: %m");

	ev.events = POLLIN_SET;
	ev.data.fd = sock;
	if (epoll_ctl(epfd, EPOLL_CTL_ADD, sock, &ev) < 0)
		return log_error(false, "Failed adding socket to epoll: %m");

again:
	if ((now = time(NULL)) < 0)
		return false;

	deltatime = (starttime + timeout) - now;
	if (deltatime < 0)
		return false;

	ret = epoll_wait(epfd, &ev, 1, 1000*deltatime + 1);
	if (ret < 0 && errno == EINTR)
		goto again;

	if (ret <= 0)
		return false;

	return true;
}

bool recv_creds(int sock, struct ucred *cred, char *v)
{
	struct msghdr msg = { 0 };
	struct iovec iov;
	struct cmsghdr *cmsg;
	char cmsgbuf[CMSG_SPACE(sizeof(*cred))];
	char buf[1];
	int ret;
	int optval = 1;

	*v = '1';

	cred->pid = -1;
	cred->uid = -1;
	cred->gid = -1;

	if (setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &optval, sizeof(optval)) == -1)
		return log_error(false, "Failed to set passcred: %s\n", strerror(errno));

	buf[0] = '1';
	if (write(sock, buf, 1) != 1)
		return log_error(false, "Failed to start write on scm fd: %s\n", strerror(errno));

	msg.msg_name = NULL;
	msg.msg_namelen = 0;
	msg.msg_control = cmsgbuf;
	msg.msg_controllen = sizeof(cmsgbuf);

	iov.iov_base = buf;
	iov.iov_len = sizeof(buf);
	msg.msg_iov = &iov;
	msg.msg_iovlen = 1;

	if (!wait_for_sock(sock, 2))
		return log_error(false, "Timed out waiting for scm_cred: %s\n", strerror(errno));

	ret = recvmsg(sock, &msg, MSG_DONTWAIT);
	if (ret < 0)
		return log_error(false, "Failed to receive scm_cred: %s\n", strerror(errno));

	cmsg = CMSG_FIRSTHDR(&msg);

	if (cmsg && cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred)) &&
			cmsg->cmsg_level == SOL_SOCKET &&
			cmsg->cmsg_type == SCM_CREDENTIALS) {
		memcpy(cred, CMSG_DATA(cmsg), sizeof(*cred));
	}
	*v = buf[0];

	return true;
}

static int msgrecv(int sockfd, void *buf, size_t len)
{
	if (!wait_for_sock(sockfd, 2))
		return -1;

	return recv(sockfd, buf, len, MSG_DONTWAIT);
}

int send_creds(int sock, struct ucred *cred, char v, bool pingfirst)
{
	struct msghdr msg = { 0 };
	struct iovec iov;
	struct cmsghdr *cmsg;
	char cmsgbuf[CMSG_SPACE(sizeof(*cred))];
	char buf[1];
	buf[0] = 'p';

	if (pingfirst && msgrecv(sock, buf, 1) != 1)
		return log_error(SEND_CREDS_FAIL, "%s - Failed getting reply from server over socketpair: %d",
				 strerror(errno), SEND_CREDS_FAIL);

	msg.msg_control = cmsgbuf;
	msg.msg_controllen = sizeof(cmsgbuf);

	cmsg = CMSG_FIRSTHDR(&msg);
	cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
	cmsg->cmsg_level = SOL_SOCKET;
	cmsg->cmsg_type = SCM_CREDENTIALS;
	memcpy(CMSG_DATA(cmsg), cred, sizeof(*cred));

	msg.msg_name = NULL;
	msg.msg_namelen = 0;

	buf[0] = v;
	iov.iov_base = buf;
	iov.iov_len = sizeof(buf);
	msg.msg_iov = &iov;
	msg.msg_iovlen = 1;

	if (sendmsg(sock, &msg, 0) < 0) {
		if (errno == 3)
			return log_error(SEND_CREDS_NOTSK, "%s - Failed at sendmsg: %d", strerror(errno), SEND_CREDS_NOTSK);

		return log_error(SEND_CREDS_FAIL, "%s - Failed at sendmsg: %d", strerror(errno), SEND_CREDS_FAIL);
	}

	return SEND_CREDS_OK;
}

int read_file_fuse(const char *path, char *buf, size_t size, struct file_info *d)
{
	__do_free char *line = NULL;
	__do_fclose FILE *f = NULL;
	size_t linelen = 0, total_len = 0;
	char *cache = d->buf;
	size_t cache_size = d->buflen;

	f = fopen(path, "re");
	if (!f)
		return 0;

	while (getline(&line, &linelen, f) != -1) {
		ssize_t l = snprintf(cache, cache_size, "%s", line);
		if (l < 0)
			return log_error(0, "Failed to write cache");
		if (l >= cache_size)
			return log_error(0, "Write to cache was truncated");

		cache += l;
		cache_size -= l;
		total_len += l;
	}

	d->size = total_len;
	if (total_len > size)
		total_len = size;

	/* read from off 0 */
	memcpy(buf, d->buf, total_len);

	if (d->size > total_len)
		d->cached = d->size - total_len;

	return total_len;
}

int read_file_fuse_with_offset(const char *path, char *buf, size_t size,
			       off_t offset, struct file_info *d)
{
	if (offset) {
		ssize_t total_len = 0;
		char *cache = d->buf;
		int left;

		if (offset > d->size)
			return -EINVAL;

		if (!d->cached)
			return 0;

		left = d->size - offset;
		total_len = left > size ? size : left;
		memcpy(buf, cache + offset, total_len);

		return total_len;
	}

	return read_file_fuse(path, buf, size, d);
}

#define INITSCOPE "/init.scope"
void prune_init_slice(char *cg)
{
	char *point;
	size_t cg_len = strlen(cg), initscope_len = strlen(INITSCOPE);

	if (cg_len < initscope_len)
		return;

	point = cg + cg_len - initscope_len;
	if (strcmp(point, INITSCOPE) == 0) {
		if (point == cg)
			*(point + 1) = '\0';
		else
			*point = '\0';
	}
}

int wait_for_pid(pid_t pid)
{
	int status, ret;

	if (pid <= 0)
		return -1;

again:
	ret = waitpid(pid, &status, 0);
	if (ret == -1) {
		if (errno == EINTR)
			goto again;
		return -1;
	}
	if (ret != pid)
		goto again;
	if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
		return -1;
	return 0;
}

static ssize_t read_nointr(int fd, void *buf, size_t count)
{
	ssize_t ret;
again:
	ret = read(fd, buf, count);
	if (ret < 0 && errno == EINTR)
		goto again;

	return ret;
}

static void *must_realloc(void *orig, size_t sz)
{
	void *ret;

	do {
		ret = realloc(orig, sz);
	} while (!ret);

	return ret;
}

static char *fd_to_buf(int fd, size_t *length)
{
	__do_free char *copy = NULL;

	if (!length)
		return NULL;

	*length = 0;
	for (;;) {
		ssize_t bytes_read;
		char buf[4096];
		char *old = copy;

		bytes_read = read_nointr(fd, buf, sizeof(buf));
		if (bytes_read < 0)
			return NULL;

		if (!bytes_read)
			break;

		copy = must_realloc(old, (*length + bytes_read) * sizeof(*old));
		memcpy(copy + *length, buf, bytes_read);
		*length += bytes_read;
	}

	return move_ptr(copy);
}

static char *file_to_buf(const char *path, size_t *length)
{
	__do_close int fd = -EBADF;

	if (!length)
		return NULL;

	fd = open(path, O_RDONLY | O_CLOEXEC);
	if (fd < 0)
		return NULL;

	return fd_to_buf(fd, length);
}

FILE *fopen_cached(const char *path, const char *mode, void **caller_freed_buffer)
{
	__do_free char *buf = NULL;
	size_t len = 0;
	FILE *f;

	buf = file_to_buf(path, &len);
	if (!buf)
		return NULL;

	f = fmemopen(buf, len, mode);
	if (!f)
		return NULL;
	*caller_freed_buffer = move_ptr(buf);
	return f;
}

FILE *fdopen_cached(int fd, const char *mode, void **caller_freed_buffer)
{
	__do_free char *buf = NULL;
	size_t len = 0;
	FILE *f;

	buf = fd_to_buf(fd, &len);
	if (!buf)
		return NULL;

	f = fmemopen(buf, len, mode);
	if (!f)
		return NULL;

	*caller_freed_buffer = move_ptr(buf);
	return f;
}

ssize_t write_nointr(int fd, const void *buf, size_t count)
{
	ssize_t ret;

	do {
		ret = write(fd, buf, count);
	} while (ret < 0 && errno == EINTR);

	return ret;
}

int safe_uint64(const char *numstr, uint64_t *converted, int base)
{
	char *err = NULL;
	uint64_t u;

	while (isspace(*numstr))
		numstr++;

	if (*numstr == '-')
		return -EINVAL;

	errno = 0;
	u = strtoull(numstr, &err, base);
	if (errno == ERANGE && u == UINT64_MAX)
		return -ERANGE;

	if (err == numstr || *err != '\0')
		return -EINVAL;

	*converted = u;
	return 0;
}
Commit	Line	Data
db0463bf	1	/* SPDX-License-Identifier: LGPL-2.1+ */
1f5596dd CB	2
	3	#ifndef _GNU_SOURCE
	4	#define _GNU_SOURCE
	5	#endif
	6
	7	#ifndef FUSE_USE_VERSION
	8	#define FUSE_USE_VERSION 26
	9	#endif
	10
	11	#define _FILE_OFFSET_BITS 64
	12
b0f33646	13	#include <ctype.h>
1d81c6a6 CB	14	#include <errno.h>
1d81c6a6 CB	15	#include <fcntl.h>
1f5596dd	16	#include <fuse.h>
1d81c6a6 CB	17	#include <inttypes.h>
	18	#include <sched.h>
	19	#include <stdarg.h>
	20	#include <stdbool.h>
	21	#include <stdint.h>
	22	#include <stdio.h>
	23	#include <stdlib.h>
	24	#include <string.h>
1f5596dd	25	#include <sys/epoll.h>
1d81c6a6 CB	26	#include <sys/stat.h>
1d81c6a6 CB	27	#include <sys/types.h>
4ec5c9da	28	#include <sys/wait.h>
1d81c6a6 CB	29	#include <unistd.h>
1d81c6a6 CB	30
1f5596dd	31	#include "bindings.h"
1d81c6a6 CB	32	#include "config.h"
	33	#include "macro.h"
	34	#include "memory_utils.h"
	35	#include "utils.h"
	36
	37	/*
	38	* append the given formatted string to *src.
	39	* src: a pointer to a char* in which to append the formatted string.
	40	* sz: the number of characters printed so far, minus trailing \0.
	41	* asz: the allocated size so far
	42	* format: string format. See printf for details.
	43	* ...: varargs. See printf for details.
	44	*/
87f7558b CB	45	/*
	46	* append the given formatted string to *src.
	47	* src: a pointer to a char* in which to append the formatted string.
	48	* sz: the number of characters printed so far, minus trailing \0.
	49	* asz: the allocated size so far
	50	* format: string format. See printf for details.
	51	* ...: varargs. See printf for details.
	52	*/
	53	char must_strcat(char src, size_t sz, size_t asz, const char format, ...)
1d81c6a6 CB	54	{
1d81c6a6 CB	55	char tmp[BUF_RESERVE_SIZE];
87f7558b CB	56	va_list args;
87f7558b CB	57	int tmplen;
1d81c6a6 CB	58
1d81c6a6 CB	59	va_start (args, format);
87f7558b	60	tmplen = vsnprintf(tmp, BUF_RESERVE_SIZE, format, args);
1d81c6a6 CB	61	va_end(args);
	62
	63	if (!src \|\| tmplen + sz + 1 >= *asz) {
87f7558b	64	char *str;
1d81c6a6	65	do {
87f7558b CB	66	str = realloc(src, asz + BUF_RESERVE_SIZE);
	67	} while (!str);
	68	*src = str;
1d81c6a6 CB	69	*asz += BUF_RESERVE_SIZE;
	70	}
	71	memcpy((src) +sz , tmp, tmplen+1); /* include the \0 */
	72	*sz += tmplen;
87f7558b CB	73
87f7558b CB	74	return *src;
1d81c6a6 CB	75	}
	76
	77	/**
	78	* in_same_namespace - Check whether two processes are in the same namespace.
	79	* @pid1 - PID of the first process.
	80	* @pid2 - PID of the second process.
	81	* @ns - Name of the namespace to check. Must correspond to one of the names
	82	* for the namespaces as shown in /proc/<pid/ns/
	83	*
	84	* If the two processes are not in the same namespace returns an fd to the
	85	* namespace of the second process identified by @pid2. If the two processes are
	86	* in the same namespace returns -EINVAL, -1 if an error occurred.
	87	*/
	88	static int in_same_namespace(pid_t pid1, pid_t pid2, const char *ns)
	89	{
05b7a16d	90	__do_close int ns_fd1 = -1, ns_fd2 = -1;
1d81c6a6 CB	91	int ret = -1;
	92	struct stat ns_st1, ns_st2;
	93
	94	ns_fd1 = preserve_ns(pid1, ns);
	95	if (ns_fd1 < 0) {
	96	/* The kernel does not support this namespace. This is not an
	97	* error.
	98	*/
	99	if (errno == ENOENT)
	100	return -EINVAL;
	101
	102	return -1;
	103	}
	104
	105	ns_fd2 = preserve_ns(pid2, ns);
	106	if (ns_fd2 < 0)
	107	return -1;
	108
	109	ret = fstat(ns_fd1, &ns_st1);
	110	if (ret < 0)
	111	return -1;
	112
	113	ret = fstat(ns_fd2, &ns_st2);
	114	if (ret < 0)
	115	return -1;
	116
	117	/* processes are in the same namespace */
	118	if ((ns_st1.st_dev == ns_st2.st_dev) && (ns_st1.st_ino == ns_st2.st_ino))
	119	return -EINVAL;
	120
	121	/* processes are in different namespaces */
	122	return move_fd(ns_fd2);
	123	}
	124
	125	bool is_shared_pidns(pid_t pid)
	126	{
	127	if (pid != 1)
	128	return false;
	129
	130	if (in_same_namespace(pid, getpid(), "pid") == -EINVAL)
	131	return true;
	132
	133	return false;
	134	}
	135
	136	int preserve_ns(const int pid, const char *ns)
	137	{
	138	int ret;
	139	/* 5 /proc + 21 /int_as_str + 3 /ns + 20 /NS_NAME + 1 \0 */
	140	#define __NS_PATH_LEN 50
	141	char path[__NS_PATH_LEN];
	142
	143	/* This way we can use this function to also check whether namespaces
	144	* are supported by the kernel by passing in the NULL or the empty
	145	* string.
	146	*/
	147	ret = snprintf(path, __NS_PATH_LEN, "/proc/%d/ns%s%s", pid,
	148	!ns \|\| strcmp(ns, "") == 0 ? "" : "/",
	149	!ns \|\| strcmp(ns, "") == 0 ? "" : ns);
	150	if (ret < 0 \|\| (size_t)ret >= __NS_PATH_LEN) {
	151	errno = EFBIG;
	152	return -1;
	153	}
	154
155	return open(path, O_RDONLY \| O_CLOEXEC);
156	}
580fe4df CB	157
	158	void do_release_file_info(struct fuse_file_info *fi)
	159	{
99b183fb	160	struct file_info *f;
580fe4df	161
99b183fb	162	f = INTTYPE_TO_PTR(fi->fh);
580fe4df CB	163	if (!f)
	164	return;
	165
	166	fi->fh = 0;
	167
	168	free_disarm(f->controller);
	169	free_disarm(f->cgroup);
	170	free_disarm(f->file);
	171	free_disarm(f->buf);
	172	free_disarm(f);
	173	}
1f5596dd CB	174
	175	#define POLLIN_SET ( EPOLLIN \| EPOLLHUP \| EPOLLRDHUP )
	176
	177	bool wait_for_sock(int sock, int timeout)
	178	{
05b7a16d	179	__do_close int epfd = -EBADF;
1f5596dd	180	struct epoll_event ev;
915c14d0	181	int ret, now, starttime, deltatime;
1f5596dd CB	182
	183	if ((starttime = time(NULL)) < 0)
	184	return false;
	185
41eb015d CB	186	epfd = epoll_create(1);
	187	if (epfd < 0)
	188	return log_error(false, "%s\n", "Failed to create epoll socket: %m");
1f5596dd CB	189
	190	ev.events = POLLIN_SET;
	191	ev.data.fd = sock;
41eb015d CB	192	if (epoll_ctl(epfd, EPOLL_CTL_ADD, sock, &ev) < 0)
41eb015d CB	193	return log_error(false, "Failed adding socket to epoll: %m");
1f5596dd CB	194
1f5596dd CB	195	again:
41eb015d	196	if ((now = time(NULL)) < 0)
1f5596dd	197	return false;
1f5596dd CB	198
1f5596dd CB	199	deltatime = (starttime + timeout) - now;
41eb015d	200	if (deltatime < 0)
1f5596dd	201	return false;
41eb015d	202
1f5596dd CB	203	ret = epoll_wait(epfd, &ev, 1, 1000*deltatime + 1);
	204	if (ret < 0 && errno == EINTR)
	205	goto again;
1f5596dd	206
41eb015d	207	if (ret <= 0)
1f5596dd	208	return false;
41eb015d	209
1f5596dd CB	210	return true;
	211	}
	212
	213	bool recv_creds(int sock, struct ucred cred, char v)
	214	{
	215	struct msghdr msg = { 0 };
	216	struct iovec iov;
	217	struct cmsghdr *cmsg;
	218	char cmsgbuf[CMSG_SPACE(sizeof(*cred))];
	219	char buf[1];
	220	int ret;
	221	int optval = 1;
	222
	223	*v = '1';
	224
	225	cred->pid = -1;
	226	cred->uid = -1;
	227	cred->gid = -1;
	228
41eb015d CB	229	if (setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &optval, sizeof(optval)) == -1)
	230	return log_error(false, "Failed to set passcred: %s\n", strerror(errno));
	231
1f5596dd	232	buf[0] = '1';
41eb015d CB	233	if (write(sock, buf, 1) != 1)
41eb015d CB	234	return log_error(false, "Failed to start write on scm fd: %s\n", strerror(errno));
1f5596dd CB	235
	236	msg.msg_name = NULL;
	237	msg.msg_namelen = 0;
	238	msg.msg_control = cmsgbuf;
	239	msg.msg_controllen = sizeof(cmsgbuf);
	240
	241	iov.iov_base = buf;
	242	iov.iov_len = sizeof(buf);
	243	msg.msg_iov = &iov;
	244	msg.msg_iovlen = 1;
	245
41eb015d CB	246	if (!wait_for_sock(sock, 2))
	247	return log_error(false, "Timed out waiting for scm_cred: %s\n", strerror(errno));
	248
1f5596dd	249	ret = recvmsg(sock, &msg, MSG_DONTWAIT);
41eb015d CB	250	if (ret < 0)
41eb015d CB	251	return log_error(false, "Failed to receive scm_cred: %s\n", strerror(errno));
1f5596dd CB	252
	253	cmsg = CMSG_FIRSTHDR(&msg);
	254
	255	if (cmsg && cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred)) &&
	256	cmsg->cmsg_level == SOL_SOCKET &&
	257	cmsg->cmsg_type == SCM_CREDENTIALS) {
	258	memcpy(cred, CMSG_DATA(cmsg), sizeof(*cred));
	259	}
	260	*v = buf[0];
	261
	262	return true;
	263	}
	264
	265	static int msgrecv(int sockfd, void *buf, size_t len)
	266	{
	267	if (!wait_for_sock(sockfd, 2))
	268	return -1;
41eb015d	269
1f5596dd CB	270	return recv(sockfd, buf, len, MSG_DONTWAIT);
	271	}
	272
	273	int send_creds(int sock, struct ucred *cred, char v, bool pingfirst)
	274	{
	275	struct msghdr msg = { 0 };
	276	struct iovec iov;
	277	struct cmsghdr *cmsg;
	278	char cmsgbuf[CMSG_SPACE(sizeof(*cred))];
	279	char buf[1];
	280	buf[0] = 'p';
	281
41eb015d CB	282	if (pingfirst && msgrecv(sock, buf, 1) != 1)
	283	return log_error(SEND_CREDS_FAIL, "%s - Failed getting reply from server over socketpair: %d",
	284	strerror(errno), SEND_CREDS_FAIL);
1f5596dd CB	285
	286	msg.msg_control = cmsgbuf;
	287	msg.msg_controllen = sizeof(cmsgbuf);
	288
	289	cmsg = CMSG_FIRSTHDR(&msg);
	290	cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
	291	cmsg->cmsg_level = SOL_SOCKET;
	292	cmsg->cmsg_type = SCM_CREDENTIALS;
	293	memcpy(CMSG_DATA(cmsg), cred, sizeof(*cred));
	294
	295	msg.msg_name = NULL;
	296	msg.msg_namelen = 0;
	297
	298	buf[0] = v;
	299	iov.iov_base = buf;
	300	iov.iov_len = sizeof(buf);
	301	msg.msg_iov = &iov;
	302	msg.msg_iovlen = 1;
	303
	304	if (sendmsg(sock, &msg, 0) < 0) {
1f5596dd	305	if (errno == 3)
41eb015d CB	306	return log_error(SEND_CREDS_NOTSK, "%s - Failed at sendmsg: %d", strerror(errno), SEND_CREDS_NOTSK);
	307
	308	return log_error(SEND_CREDS_FAIL, "%s - Failed at sendmsg: %d", strerror(errno), SEND_CREDS_FAIL);
1f5596dd CB	309	}
	310
	311	return SEND_CREDS_OK;
	312	}
	313
	314	int read_file_fuse(const char path, char buf, size_t size, struct file_info *d)
	315	{
	316	__do_free char *line = NULL;
	317	__do_fclose FILE *f = NULL;
	318	size_t linelen = 0, total_len = 0;
	319	char *cache = d->buf;
	320	size_t cache_size = d->buflen;
	321
dbb1f822	322	f = fopen(path, "re");
1f5596dd CB	323	if (!f)
	324	return 0;
	325
	326	while (getline(&line, &linelen, f) != -1) {
	327	ssize_t l = snprintf(cache, cache_size, "%s", line);
41eb015d CB	328	if (l < 0)
	329	return log_error(0, "Failed to write cache");
	330	if (l >= cache_size)
	331	return log_error(0, "Write to cache was truncated");
	332
1f5596dd CB	333	cache += l;
	334	cache_size -= l;
	335	total_len += l;
	336	}
	337
	338	d->size = total_len;
	339	if (total_len > size)
	340	total_len = size;
	341
	342	/* read from off 0 */
	343	memcpy(buf, d->buf, total_len);
	344
	345	if (d->size > total_len)
	346	d->cached = d->size - total_len;
cbfc55fd	347
1f5596dd CB	348	return total_len;
1f5596dd CB	349	}
4ec5c9da	350
cbfc55fd CB	351	int read_file_fuse_with_offset(const char path, char buf, size_t size,
	352	off_t offset, struct file_info *d)
	353	{
	354	if (offset) {
	355	ssize_t total_len = 0;
	356	char *cache = d->buf;
	357	int left;
	358
	359	if (offset > d->size)
	360	return -EINVAL;
	361
	362	if (!d->cached)
	363	return 0;
	364
	365	left = d->size - offset;
	366	total_len = left > size ? size : left;
	367	memcpy(buf, cache + offset, total_len);
	368
	369	return total_len;
	370	}
	371
	372	return read_file_fuse(path, buf, size, d);
	373	}
	374
4ec5c9da CB	375	#define INITSCOPE "/init.scope"
	376	void prune_init_slice(char *cg)
	377	{
	378	char *point;
	379	size_t cg_len = strlen(cg), initscope_len = strlen(INITSCOPE);
	380
	381	if (cg_len < initscope_len)
	382	return;
	383
	384	point = cg + cg_len - initscope_len;
	385	if (strcmp(point, INITSCOPE) == 0) {
	386	if (point == cg)
700dd417	387	*(point + 1) = '\0';
4ec5c9da CB	388	else
	389	*point = '\0';
	390	}
	391	}
	392
	393	int wait_for_pid(pid_t pid)
	394	{
	395	int status, ret;
	396
	397	if (pid <= 0)
	398	return -1;
	399
	400	again:
	401	ret = waitpid(pid, &status, 0);
	402	if (ret == -1) {
	403	if (errno == EINTR)
	404	goto again;
	405	return -1;
	406	}
	407	if (ret != pid)
	408	goto again;
	409	if (!WIFEXITED(status) \|\| WEXITSTATUS(status) != 0)
	410	return -1;
	411	return 0;
	412	}
757a63e7 CB	413
	414	static ssize_t read_nointr(int fd, void *buf, size_t count)
	415	{
	416	ssize_t ret;
	417	again:
	418	ret = read(fd, buf, count);
	419	if (ret < 0 && errno == EINTR)
	420	goto again;
	421
	422	return ret;
	423	}
	424
	425	static void must_realloc(void orig, size_t sz)
	426	{
	427	void *ret;
	428
	429	do {
	430	ret = realloc(orig, sz);
	431	} while (!ret);
	432
	433	return ret;
	434	}
	435
28519477	436	static char fd_to_buf(int fd, size_t length)
757a63e7	437	{
757a63e7	438	__do_free char *copy = NULL;
757a63e7 CB	439
	440	if (!length)
	441	return NULL;
	442
757a63e7 CB	443	*length = 0;
757a63e7 CB	444	for (;;) {
28519477 CB	445	ssize_t bytes_read;
28519477 CB	446	char buf[4096];
757a63e7 CB	447	char *old = copy;
757a63e7 CB	448
28519477 CB	449	bytes_read = read_nointr(fd, buf, sizeof(buf));
28519477 CB	450	if (bytes_read < 0)
757a63e7	451	return NULL;
28519477 CB	452
28519477 CB	453	if (!bytes_read)
757a63e7 CB	454	break;
757a63e7 CB	455
28519477 CB	456	copy = must_realloc(old, (length + bytes_read) sizeof(*old));
	457	memcpy(copy + *length, buf, bytes_read);
	458	*length += bytes_read;
757a63e7 CB	459	}
	460
	461	return move_ptr(copy);
	462	}
	463
28519477 CB	464	static char file_to_buf(const char path, size_t *length)
28519477 CB	465	{
05b7a16d	466	__do_close int fd = -EBADF;
28519477 CB	467
	468	if (!length)
	469	return NULL;
	470
	471	fd = open(path, O_RDONLY \| O_CLOEXEC);
	472	if (fd < 0)
	473	return NULL;
	474
	475	return fd_to_buf(fd, length);
	476	}
	477
757a63e7 CB	478	FILE fopen_cached(const char path, const char mode, void *caller_freed_buffer)
	479	{
	480	__do_free char *buf = NULL;
	481	size_t len = 0;
	482	FILE *f;
	483
	484	buf = file_to_buf(path, &len);
	485	if (!buf)
	486	return NULL;
	487
	488	f = fmemopen(buf, len, mode);
	489	if (!f)
	490	return NULL;
	491	*caller_freed_buffer = move_ptr(buf);
	492	return f;
	493	}
28519477	494
28519477 CB	495	FILE fdopen_cached(int fd, const char mode, void **caller_freed_buffer)
	496	{
	497	__do_free char *buf = NULL;
	498	size_t len = 0;
	499	FILE *f;
	500
	501	buf = fd_to_buf(fd, &len);
	502	if (!buf)
	503	return NULL;
	504
	505	f = fmemopen(buf, len, mode);
	506	if (!f)
	507	return NULL;
	508
	509	*caller_freed_buffer = move_ptr(buf);
	510	return f;
	511	}
2f543378 CB	512
	513	ssize_t write_nointr(int fd, const void *buf, size_t count)
	514	{
	515	ssize_t ret;
	516
	517	do {
	518	ret = write(fd, buf, count);
	519	} while (ret < 0 && errno == EINTR);
	520
	521	return ret;
	522	}
b0f33646 CB	523
	524	int safe_uint64(const char numstr, uint64_t converted, int base)
	525	{
	526	char *err = NULL;
	527	uint64_t u;
	528
	529	while (isspace(*numstr))
	530	numstr++;
	531
	532	if (*numstr == '-')
	533	return -EINVAL;
	534
	535	errno = 0;
	536	u = strtoull(numstr, &err, base);
	537	if (errno == ERANGE && u == UINT64_MAX)
	538	return -ERANGE;
	539
	540	if (err == numstr \|\| *err != '\0')
	541	return -EINVAL;
	542
	543	*converted = u;
	544	return 0;
	545	}