[mirror_lxcfs.git] / src / utils.c

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

#include "config.h"

#include <ctype.h>
#include <errno.h>
#include <fcntl.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 "utils.h"

#include "bindings.h"
#include "macro.h"
#include "memory_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.
 */
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)
{
	__do_close int fd = -EBADF;

	if (pid != 1)
		return false;

	fd = in_same_namespace(pid, getpid(), "pid");
	if (fd == 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, "%m - Failed to create epoll socket");

	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 = {};
	struct iovec iov;
	struct cmsghdr *cmsg;
	ssize_t ret;
	char cmsgbuf[CMSG_SPACE(sizeof(*cred))] = {};
	char buf = '1';
	int optval = 1;

	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;

	*v = buf;

	ret = setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &optval, sizeof(optval));
	if (ret < 0)
		return log_error(false, "Failed to set passcred: %s\n", strerror(errno));

	ret = write_nointr(sock, &buf, sizeof(buf));
	if (ret != sizeof(buf))
		return log_error(false, "Failed to start write on scm fd: %s\n", strerror(errno));

	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(*cred)) &&
	    cmsg->cmsg_level == SOL_SOCKET &&
	    cmsg->cmsg_type == SCM_CREDENTIALS) {
		memcpy(cred, CMSG_DATA(cmsg), sizeof(*cred));
	}
	*v = buf;

	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;

		l = snprintf(cache, cache_size, "%s", line);
		if (l < 0)
			return log_error(0, "Failed to write cache");
		if ((size_t)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 > (int)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;
		size_t 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;
}

int safe_uint32(const char *numstr, uint32_t *converted, int base)
{
	char *err = NULL;
	unsigned long uli;

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

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

	errno = 0;
	uli = strtoul(numstr, &err, base);
	if (errno == ERANGE && uli == UINT32_MAX)
		return -ERANGE;

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

	*converted = (uint32_t)uli;
	return 0;
}

static int char_left_gc(const char *buffer, size_t len)
{
	size_t i;

	for (i = 0; i < len; i++) {
		if (buffer[i] == ' ' ||
		    buffer[i] == '\t')
			continue;

		return i;
	}

	return 0;
}

static int char_right_gc(const char *buffer, size_t len)
{
	int i;

	for (i = len - 1; i >= 0; i--) {
		if (buffer[i] == ' '  ||
		    buffer[i] == '\t' ||
		    buffer[i] == '\n' ||
		    buffer[i] == '\0')
			continue;

		return i + 1;
	}

	return 0;
}

char *trim_whitespace_in_place(char *buffer)
{
	buffer += char_left_gc(buffer, strlen(buffer));
	buffer[char_right_gc(buffer, strlen(buffer))] = '\0';
	return buffer;
}

#define BATCH_SIZE 50
static int batch_realloc(char **mem, size_t oldlen, size_t newlen)
{
	int newbatches = (newlen / BATCH_SIZE) + 1;
	int oldbatches = (oldlen / BATCH_SIZE) + 1;

	if (!*mem || newbatches > oldbatches) {
		char *tmp;

		tmp = realloc(*mem, newbatches * BATCH_SIZE);
		if (!tmp)
			return -ENOMEM;
		*mem = tmp;
	}

	return 0;
}

static int append_line(char **dest, size_t oldlen, char *new, size_t newlen)
{
	int ret;
	size_t full = oldlen + newlen;

	ret = batch_realloc(dest, oldlen, full + 1);
	if (ret)
		return ret;

	memcpy(*dest + oldlen, new, newlen + 1);
	return 0;
}

/* Slurp in a whole file */
char *read_file_at(int dfd, const char *fnam, unsigned int o_flags)
{
	__do_close int fd = -EBADF;
	__do_free char *buf = NULL, *line = NULL;
	__do_fclose FILE *f = NULL;
	size_t len = 0, fulllen = 0;
	int linelen;

	fd = openat(dfd, fnam, o_flags, 0);
	if (fd < 0)
		return NULL;

	f = fdopen(fd, "re");
	if (!f)
		return NULL;
	/* Transfer ownership to fdopen(). */
	move_fd(fd);

	while ((linelen = getline(&line, &len, f)) != -1) {
		if (append_line(&buf, fulllen, line, linelen))
			return NULL;
		fulllen += linelen;
	}

	return move_ptr(buf);
}

DIR *opendir_flags(const char *path, int flags)
{
	__do_close int dfd = -EBADF;
	DIR *dirp;

	dfd = open(path, O_DIRECTORY | flags);
	if (dfd < 0)
		return NULL;

	dirp = fdopendir(dfd);
	if (dirp)
		move_fd(dfd); /* Transfer ownership to fdopendir(). */

	return dirp;
}

int get_task_personality(pid_t pid, __u32 *personality)
{
	__do_close int fd = -EBADF;
	int ret = -1;
	char path[STRLITERALLEN("/proc//personality") + INTTYPE_TO_STRLEN(pid_t) + 1];
	/* seq_printf(m, "%08x\n", task->personality); */
	char buf[8 + 1];

	ret = strnprintf(path, sizeof(path), "/proc/%d/personality", pid);
	if (ret < 0)
		return -1;

	fd = open(path, O_RDONLY | O_CLOEXEC);
	if (fd < 0)
		return -1;

	ret = read_nointr(fd, buf, sizeof(buf) - 1);
	if (ret >= 0) {
		buf[ret] = '\0';
		if (safe_uint32(buf, personality, 16) < 0)
			return log_error(-1, "Failed to convert personality %s", buf);
	}

	return ret;
}
Commit	Line	Data
db0463bf	1	/* SPDX-License-Identifier: LGPL-2.1+ */
1f5596dd	2
f834b6bf SP	3	#include "config.h"
f834b6bf SP	4
b0f33646	5	#include <ctype.h>
1d81c6a6 CB	6	#include <errno.h>
	7	#include <fcntl.h>
	8	#include <inttypes.h>
	9	#include <sched.h>
	10	#include <stdarg.h>
	11	#include <stdbool.h>
	12	#include <stdint.h>
	13	#include <stdio.h>
	14	#include <stdlib.h>
	15	#include <string.h>
1f5596dd	16	#include <sys/epoll.h>
1d81c6a6 CB	17	#include <sys/stat.h>
1d81c6a6 CB	18	#include <sys/types.h>
4ec5c9da	19	#include <sys/wait.h>
1d81c6a6 CB	20	#include <unistd.h>
1d81c6a6 CB	21
e01afbb7 CB	22	#include "utils.h"
e01afbb7 CB	23
1f5596dd	24	#include "bindings.h"
1d81c6a6 CB	25	#include "macro.h"
1d81c6a6 CB	26	#include "memory_utils.h"
1d81c6a6 CB	27
	28	/*
	29	* append the given formatted string to *src.
	30	* src: a pointer to a char* in which to append the formatted string.
	31	* sz: the number of characters printed so far, minus trailing \0.
	32	* asz: the allocated size so far
	33	* format: string format. See printf for details.
	34	* ...: varargs. See printf for details.
	35	*/
87f7558b	36	char must_strcat(char src, size_t sz, size_t asz, const char format, ...)
1d81c6a6 CB	37	{
1d81c6a6 CB	38	char tmp[BUF_RESERVE_SIZE];
87f7558b CB	39	va_list args;
87f7558b CB	40	int tmplen;
1d81c6a6 CB	41
1d81c6a6 CB	42	va_start (args, format);
87f7558b	43	tmplen = vsnprintf(tmp, BUF_RESERVE_SIZE, format, args);
1d81c6a6 CB	44	va_end(args);
	45
	46	if (!src \|\| tmplen + sz + 1 >= *asz) {
87f7558b	47	char *str;
1d81c6a6	48	do {
87f7558b CB	49	str = realloc(src, asz + BUF_RESERVE_SIZE);
	50	} while (!str);
	51	*src = str;
1d81c6a6 CB	52	*asz += BUF_RESERVE_SIZE;
	53	}
	54	memcpy((src) +sz , tmp, tmplen+1); /* include the \0 */
	55	*sz += tmplen;
87f7558b CB	56
87f7558b CB	57	return *src;
1d81c6a6 CB	58	}
	59
	60	/**
	61	* in_same_namespace - Check whether two processes are in the same namespace.
	62	* @pid1 - PID of the first process.
	63	* @pid2 - PID of the second process.
	64	* @ns - Name of the namespace to check. Must correspond to one of the names
	65	* for the namespaces as shown in /proc/<pid/ns/
	66	*
	67	* If the two processes are not in the same namespace returns an fd to the
	68	* namespace of the second process identified by @pid2. If the two processes are
	69	* in the same namespace returns -EINVAL, -1 if an error occurred.
	70	*/
	71	static int in_same_namespace(pid_t pid1, pid_t pid2, const char *ns)
	72	{
05b7a16d	73	__do_close int ns_fd1 = -1, ns_fd2 = -1;
1d81c6a6 CB	74	int ret = -1;
	75	struct stat ns_st1, ns_st2;
	76
	77	ns_fd1 = preserve_ns(pid1, ns);
	78	if (ns_fd1 < 0) {
	79	/* The kernel does not support this namespace. This is not an
	80	* error.
	81	*/
	82	if (errno == ENOENT)
	83	return -EINVAL;
	84
	85	return -1;
	86	}
	87
	88	ns_fd2 = preserve_ns(pid2, ns);
	89	if (ns_fd2 < 0)
	90	return -1;
	91
	92	ret = fstat(ns_fd1, &ns_st1);
	93	if (ret < 0)
	94	return -1;
	95
	96	ret = fstat(ns_fd2, &ns_st2);
	97	if (ret < 0)
	98	return -1;
	99
	100	/* processes are in the same namespace */
	101	if ((ns_st1.st_dev == ns_st2.st_dev) && (ns_st1.st_ino == ns_st2.st_ino))
	102	return -EINVAL;
	103
	104	/* processes are in different namespaces */
	105	return move_fd(ns_fd2);
	106	}
	107
	108	bool is_shared_pidns(pid_t pid)
	109	{
802b0d20 CB	110	__do_close int fd = -EBADF;
802b0d20 CB	111
1d81c6a6 CB	112	if (pid != 1)
	113	return false;
	114
802b0d20 CB	115	fd = in_same_namespace(pid, getpid(), "pid");
802b0d20 CB	116	if (fd == EINVAL)
1d81c6a6 CB	117	return true;
	118
	119	return false;
	120	}
	121
	122	int preserve_ns(const int pid, const char *ns)
	123	{
	124	int ret;
	125	/* 5 /proc + 21 /int_as_str + 3 /ns + 20 /NS_NAME + 1 \0 */
	126	#define __NS_PATH_LEN 50
	127	char path[__NS_PATH_LEN];
	128
	129	/* This way we can use this function to also check whether namespaces
	130	* are supported by the kernel by passing in the NULL or the empty
	131	* string.
	132	*/
	133	ret = snprintf(path, __NS_PATH_LEN, "/proc/%d/ns%s%s", pid,
	134	!ns \|\| strcmp(ns, "") == 0 ? "" : "/",
	135	!ns \|\| strcmp(ns, "") == 0 ? "" : ns);
	136	if (ret < 0 \|\| (size_t)ret >= __NS_PATH_LEN) {
	137	errno = EFBIG;
	138	return -1;
	139	}
	140
	141	return open(path, O_RDONLY \| O_CLOEXEC);
	142	}
580fe4df CB	143
	144	void do_release_file_info(struct fuse_file_info *fi)
	145	{
99b183fb	146	struct file_info *f;
580fe4df	147
99b183fb	148	f = INTTYPE_TO_PTR(fi->fh);
580fe4df CB	149	if (!f)
	150	return;
	151
	152	fi->fh = 0;
	153
	154	free_disarm(f->controller);
	155	free_disarm(f->cgroup);
	156	free_disarm(f->file);
	157	free_disarm(f->buf);
	158	free_disarm(f);
	159	}
1f5596dd CB	160
	161	#define POLLIN_SET ( EPOLLIN \| EPOLLHUP \| EPOLLRDHUP )
	162
	163	bool wait_for_sock(int sock, int timeout)
	164	{
05b7a16d	165	__do_close int epfd = -EBADF;
1f5596dd	166	struct epoll_event ev;
915c14d0	167	int ret, now, starttime, deltatime;
1f5596dd CB	168
	169	if ((starttime = time(NULL)) < 0)
	170	return false;
	171
41eb015d CB	172	epfd = epoll_create(1);
41eb015d CB	173	if (epfd < 0)
e4bd0d4d	174	return log_error(false, "%m - Failed to create epoll socket");
1f5596dd CB	175
	176	ev.events = POLLIN_SET;
	177	ev.data.fd = sock;
41eb015d CB	178	if (epoll_ctl(epfd, EPOLL_CTL_ADD, sock, &ev) < 0)
41eb015d CB	179	return log_error(false, "Failed adding socket to epoll: %m");
1f5596dd CB	180
1f5596dd CB	181	again:
41eb015d	182	if ((now = time(NULL)) < 0)
1f5596dd	183	return false;
1f5596dd CB	184
1f5596dd CB	185	deltatime = (starttime + timeout) - now;
41eb015d	186	if (deltatime < 0)
1f5596dd	187	return false;
41eb015d	188
1f5596dd CB	189	ret = epoll_wait(epfd, &ev, 1, 1000*deltatime + 1);
	190	if (ret < 0 && errno == EINTR)
	191	goto again;
1f5596dd	192
41eb015d	193	if (ret <= 0)
1f5596dd	194	return false;
41eb015d	195
1f5596dd CB	196	return true;
	197	}
	198
	199	bool recv_creds(int sock, struct ucred cred, char v)
	200	{
dac3dc93	201	struct msghdr msg = {};
1f5596dd CB	202	struct iovec iov;
1f5596dd CB	203	struct cmsghdr *cmsg;
dac3dc93 CB	204	ssize_t ret;
	205	char cmsgbuf[CMSG_SPACE(sizeof(*cred))] = {};
	206	char buf = '1';
1f5596dd CB	207	int optval = 1;
1f5596dd CB	208
1f5596dd CB	209	msg.msg_name = NULL;
	210	msg.msg_namelen = 0;
	211	msg.msg_control = cmsgbuf;
	212	msg.msg_controllen = sizeof(cmsgbuf);
	213
dac3dc93	214	iov.iov_base = &buf;
1f5596dd CB	215	iov.iov_len = sizeof(buf);
	216	msg.msg_iov = &iov;
	217	msg.msg_iovlen = 1;
	218
dac3dc93 CB	219	*v = buf;
	220
	221	ret = setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &optval, sizeof(optval));
	222	if (ret < 0)
	223	return log_error(false, "Failed to set passcred: %s\n", strerror(errno));
	224
	225	ret = write_nointr(sock, &buf, sizeof(buf));
	226	if (ret != sizeof(buf))
	227	return log_error(false, "Failed to start write on scm fd: %s\n", strerror(errno));
	228
41eb015d CB	229	if (!wait_for_sock(sock, 2))
	230	return log_error(false, "Timed out waiting for scm_cred: %s\n", strerror(errno));
	231
1f5596dd	232	ret = recvmsg(sock, &msg, MSG_DONTWAIT);
41eb015d CB	233	if (ret < 0)
41eb015d CB	234	return log_error(false, "Failed to receive scm_cred: %s\n", strerror(errno));
1f5596dd CB	235
	236	cmsg = CMSG_FIRSTHDR(&msg);
	237
dac3dc93 CB	238	if (cmsg && cmsg->cmsg_len == CMSG_LEN(sizeof(*cred)) &&
	239	cmsg->cmsg_level == SOL_SOCKET &&
	240	cmsg->cmsg_type == SCM_CREDENTIALS) {
1f5596dd CB	241	memcpy(cred, CMSG_DATA(cmsg), sizeof(*cred));
1f5596dd CB	242	}
dac3dc93	243	*v = buf;
1f5596dd CB	244
	245	return true;
	246	}
	247
	248	static int msgrecv(int sockfd, void *buf, size_t len)
	249	{
	250	if (!wait_for_sock(sockfd, 2))
	251	return -1;
41eb015d	252
1f5596dd CB	253	return recv(sockfd, buf, len, MSG_DONTWAIT);
	254	}
	255
	256	int send_creds(int sock, struct ucred *cred, char v, bool pingfirst)
	257	{
	258	struct msghdr msg = { 0 };
	259	struct iovec iov;
	260	struct cmsghdr *cmsg;
	261	char cmsgbuf[CMSG_SPACE(sizeof(*cred))];
	262	char buf[1];
	263	buf[0] = 'p';
	264
41eb015d CB	265	if (pingfirst && msgrecv(sock, buf, 1) != 1)
	266	return log_error(SEND_CREDS_FAIL, "%s - Failed getting reply from server over socketpair: %d",
	267	strerror(errno), SEND_CREDS_FAIL);
1f5596dd CB	268
	269	msg.msg_control = cmsgbuf;
	270	msg.msg_controllen = sizeof(cmsgbuf);
	271
	272	cmsg = CMSG_FIRSTHDR(&msg);
	273	cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
	274	cmsg->cmsg_level = SOL_SOCKET;
	275	cmsg->cmsg_type = SCM_CREDENTIALS;
	276	memcpy(CMSG_DATA(cmsg), cred, sizeof(*cred));
	277
	278	msg.msg_name = NULL;
	279	msg.msg_namelen = 0;
	280
	281	buf[0] = v;
	282	iov.iov_base = buf;
	283	iov.iov_len = sizeof(buf);
	284	msg.msg_iov = &iov;
	285	msg.msg_iovlen = 1;
	286
	287	if (sendmsg(sock, &msg, 0) < 0) {
1f5596dd	288	if (errno == 3)
41eb015d CB	289	return log_error(SEND_CREDS_NOTSK, "%s - Failed at sendmsg: %d", strerror(errno), SEND_CREDS_NOTSK);
	290
	291	return log_error(SEND_CREDS_FAIL, "%s - Failed at sendmsg: %d", strerror(errno), SEND_CREDS_FAIL);
1f5596dd CB	292	}
	293
	294	return SEND_CREDS_OK;
	295	}
	296
	297	int read_file_fuse(const char path, char buf, size_t size, struct file_info *d)
	298	{
	299	__do_free char *line = NULL;
	300	__do_fclose FILE *f = NULL;
	301	size_t linelen = 0, total_len = 0;
	302	char *cache = d->buf;
	303	size_t cache_size = d->buflen;
	304
dbb1f822	305	f = fopen(path, "re");
1f5596dd CB	306	if (!f)
	307	return 0;
	308
	309	while (getline(&line, &linelen, f) != -1) {
3cf1e562 CB	310	ssize_t l;
	311
	312	l = snprintf(cache, cache_size, "%s", line);
41eb015d CB	313	if (l < 0)
41eb015d CB	314	return log_error(0, "Failed to write cache");
3cf1e562	315	if ((size_t)l >= cache_size)
41eb015d CB	316	return log_error(0, "Write to cache was truncated");
41eb015d CB	317
1f5596dd CB	318	cache += l;
	319	cache_size -= l;
	320	total_len += l;
	321	}
	322
	323	d->size = total_len;
	324	if (total_len > size)
	325	total_len = size;
	326
	327	/* read from off 0 */
	328	memcpy(buf, d->buf, total_len);
	329
3cf1e562	330	if (d->size > (int)total_len)
1f5596dd	331	d->cached = d->size - total_len;
cbfc55fd	332
1f5596dd CB	333	return total_len;
1f5596dd CB	334	}
4ec5c9da	335
cbfc55fd CB	336	int read_file_fuse_with_offset(const char path, char buf, size_t size,
	337	off_t offset, struct file_info *d)
	338	{
	339	if (offset) {
	340	ssize_t total_len = 0;
	341	char *cache = d->buf;
3cf1e562	342	size_t left;
cbfc55fd CB	343
	344	if (offset > d->size)
	345	return -EINVAL;
	346
	347	if (!d->cached)
	348	return 0;
	349
	350	left = d->size - offset;
	351	total_len = left > size ? size : left;
	352	memcpy(buf, cache + offset, total_len);
	353
	354	return total_len;
	355	}
	356
	357	return read_file_fuse(path, buf, size, d);
	358	}
	359
4ec5c9da CB	360	#define INITSCOPE "/init.scope"
	361	void prune_init_slice(char *cg)
	362	{
	363	char *point;
	364	size_t cg_len = strlen(cg), initscope_len = strlen(INITSCOPE);
	365
	366	if (cg_len < initscope_len)
	367	return;
	368
	369	point = cg + cg_len - initscope_len;
	370	if (strcmp(point, INITSCOPE) == 0) {
	371	if (point == cg)
700dd417	372	*(point + 1) = '\0';
4ec5c9da CB	373	else
	374	*point = '\0';
	375	}
	376	}
	377
	378	int wait_for_pid(pid_t pid)
	379	{
	380	int status, ret;
	381
	382	if (pid <= 0)
	383	return -1;
	384
	385	again:
	386	ret = waitpid(pid, &status, 0);
	387	if (ret == -1) {
	388	if (errno == EINTR)
	389	goto again;
	390	return -1;
	391	}
	392	if (ret != pid)
	393	goto again;
	394	if (!WIFEXITED(status) \|\| WEXITSTATUS(status) != 0)
	395	return -1;
	396	return 0;
	397	}
757a63e7 CB	398
	399	static ssize_t read_nointr(int fd, void *buf, size_t count)
	400	{
	401	ssize_t ret;
	402	again:
	403	ret = read(fd, buf, count);
	404	if (ret < 0 && errno == EINTR)
	405	goto again;
	406
	407	return ret;
	408	}
	409
	410	static void must_realloc(void orig, size_t sz)
	411	{
	412	void *ret;
	413
	414	do {
	415	ret = realloc(orig, sz);
	416	} while (!ret);
	417
	418	return ret;
	419	}
	420
28519477	421	static char fd_to_buf(int fd, size_t length)
757a63e7	422	{
757a63e7	423	__do_free char *copy = NULL;
757a63e7 CB	424
	425	if (!length)
	426	return NULL;
	427
757a63e7 CB	428	*length = 0;
757a63e7 CB	429	for (;;) {
28519477 CB	430	ssize_t bytes_read;
28519477 CB	431	char buf[4096];
757a63e7 CB	432	char *old = copy;
757a63e7 CB	433
28519477 CB	434	bytes_read = read_nointr(fd, buf, sizeof(buf));
28519477 CB	435	if (bytes_read < 0)
757a63e7	436	return NULL;
28519477 CB	437
28519477 CB	438	if (!bytes_read)
757a63e7 CB	439	break;
757a63e7 CB	440
28519477 CB	441	copy = must_realloc(old, (length + bytes_read) sizeof(*old));
	442	memcpy(copy + *length, buf, bytes_read);
	443	*length += bytes_read;
757a63e7 CB	444	}
	445
	446	return move_ptr(copy);
	447	}
	448
28519477 CB	449	static char file_to_buf(const char path, size_t *length)
28519477 CB	450	{
05b7a16d	451	__do_close int fd = -EBADF;
28519477 CB	452
	453	if (!length)
	454	return NULL;
	455
	456	fd = open(path, O_RDONLY \| O_CLOEXEC);
	457	if (fd < 0)
	458	return NULL;
	459
	460	return fd_to_buf(fd, length);
	461	}
	462
757a63e7 CB	463	FILE fopen_cached(const char path, const char mode, void *caller_freed_buffer)
	464	{
	465	__do_free char *buf = NULL;
	466	size_t len = 0;
	467	FILE *f;
	468
	469	buf = file_to_buf(path, &len);
	470	if (!buf)
	471	return NULL;
	472
	473	f = fmemopen(buf, len, mode);
	474	if (!f)
	475	return NULL;
	476	*caller_freed_buffer = move_ptr(buf);
	477	return f;
	478	}
28519477	479
28519477 CB	480	FILE fdopen_cached(int fd, const char mode, void **caller_freed_buffer)
	481	{
	482	__do_free char *buf = NULL;
	483	size_t len = 0;
	484	FILE *f;
	485
	486	buf = fd_to_buf(fd, &len);
	487	if (!buf)
	488	return NULL;
	489
	490	f = fmemopen(buf, len, mode);
	491	if (!f)
	492	return NULL;
	493
	494	*caller_freed_buffer = move_ptr(buf);
	495	return f;
	496	}
2f543378 CB	497
	498	ssize_t write_nointr(int fd, const void *buf, size_t count)
	499	{
	500	ssize_t ret;
	501
	502	do {
	503	ret = write(fd, buf, count);
	504	} while (ret < 0 && errno == EINTR);
	505
	506	return ret;
	507	}
b0f33646 CB	508
	509	int safe_uint64(const char numstr, uint64_t converted, int base)
	510	{
	511	char *err = NULL;
	512	uint64_t u;
	513
	514	while (isspace(*numstr))
	515	numstr++;
	516
	517	if (*numstr == '-')
	518	return -EINVAL;
	519
	520	errno = 0;
	521	u = strtoull(numstr, &err, base);
	522	if (errno == ERANGE && u == UINT64_MAX)
	523	return -ERANGE;
	524
	525	if (err == numstr \|\| *err != '\0')
	526	return -EINVAL;
	527
	528	*converted = u;
	529	return 0;
	530	}
8b6987a2	531
649e9ccc AM	532	int safe_uint32(const char numstr, uint32_t converted, int base)
	533	{
	534	char *err = NULL;
	535	unsigned long uli;
	536
	537	while (isspace(*numstr))
	538	numstr++;
	539
	540	if (*numstr == '-')
	541	return -EINVAL;
	542
	543	errno = 0;
	544	uli = strtoul(numstr, &err, base);
	545	if (errno == ERANGE && uli == UINT32_MAX)
	546	return -ERANGE;
	547
	548	if (err == numstr \|\| *err != '\0')
	549	return -EINVAL;
	550
	551	*converted = (uint32_t)uli;
	552	return 0;
	553	}
	554
8b6987a2 CB	555	static int char_left_gc(const char *buffer, size_t len)
	556	{
	557	size_t i;
	558
	559	for (i = 0; i < len; i++) {
	560	if (buffer[i] == ' ' \|\|
	561	buffer[i] == '\t')
	562	continue;
	563
	564	return i;
	565	}
	566
	567	return 0;
	568	}
	569
	570	static int char_right_gc(const char *buffer, size_t len)
	571	{
	572	int i;
	573
	574	for (i = len - 1; i >= 0; i--) {
	575	if (buffer[i] == ' ' \|\|
	576	buffer[i] == '\t' \|\|
	577	buffer[i] == '\n' \|\|
	578	buffer[i] == '\0')
	579	continue;
	580
	581	return i + 1;
	582	}
	583
	584	return 0;
	585	}
	586
	587	char trim_whitespace_in_place(char buffer)
	588	{
	589	buffer += char_left_gc(buffer, strlen(buffer));
	590	buffer[char_right_gc(buffer, strlen(buffer))] = '\0';
	591	return buffer;
	592	}
a3c8d33c CB	593
	594	#define BATCH_SIZE 50
	595	static int batch_realloc(char **mem, size_t oldlen, size_t newlen)
	596	{
	597	int newbatches = (newlen / BATCH_SIZE) + 1;
	598	int oldbatches = (oldlen / BATCH_SIZE) + 1;
	599
	600	if (!*mem \|\| newbatches > oldbatches) {
	601	char *tmp;
	602
	603	tmp = realloc(mem, newbatches BATCH_SIZE);
	604	if (!tmp)
	605	return -ENOMEM;
	606	*mem = tmp;
	607	}
	608
	609	return 0;
	610	}
	611
	612	static int append_line(char *dest, size_t oldlen, char new, size_t newlen)
	613	{
	614	int ret;
	615	size_t full = oldlen + newlen;
	616
	617	ret = batch_realloc(dest, oldlen, full + 1);
	618	if (ret)
	619	return ret;
	620
	621	memcpy(*dest + oldlen, new, newlen + 1);
	622	return 0;
	623	}
	624
	625	/* Slurp in a whole file */
	626	char read_file_at(int dfd, const char fnam, unsigned int o_flags)
	627	{
	628	__do_close int fd = -EBADF;
	629	__do_free char buf = NULL, line = NULL;
	630	__do_fclose FILE *f = NULL;
	631	size_t len = 0, fulllen = 0;
	632	int linelen;
	633
	634	fd = openat(dfd, fnam, o_flags, 0);
	635	if (fd < 0)
	636	return NULL;
	637
	638	f = fdopen(fd, "re");
	639	if (!f)
	640	return NULL;
	641	/* Transfer ownership to fdopen(). */
	642	move_fd(fd);
	643
	644	while ((linelen = getline(&line, &len, f)) != -1) {
	645	if (append_line(&buf, fulllen, line, linelen))
	646	return NULL;
	647	fulllen += linelen;
	648	}
	649
	650	return move_ptr(buf);
	651	}
a6fd03eb	652
f5227e5c	653	DIR opendir_flags(const char path, int flags)
a6fd03eb CBM	654	{
	655	__do_close int dfd = -EBADF;
	656	DIR *dirp;
	657
f5227e5c	658	dfd = open(path, O_DIRECTORY \| flags);
a6fd03eb CBM	659	if (dfd < 0)
	660	return NULL;
	661
	662	dirp = fdopendir(dfd);
	663	if (dirp)
	664	move_fd(dfd); /* Transfer ownership to fdopendir(). */
	665
	666	return dirp;
	667	}
474491c4 AM	668
	669	int get_task_personality(pid_t pid, __u32 *personality)
	670	{
	671	__do_close int fd = -EBADF;
	672	int ret = -1;
	673	char path[STRLITERALLEN("/proc//personality") + INTTYPE_TO_STRLEN(pid_t) + 1];
	674	/* seq_printf(m, "%08x\n", task->personality); */
	675	char buf[8 + 1];
	676
	677	ret = strnprintf(path, sizeof(path), "/proc/%d/personality", pid);
	678	if (ret < 0)
	679	return -1;
	680
	681	fd = open(path, O_RDONLY \| O_CLOEXEC);
	682	if (fd < 0)
	683	return -1;
	684
	685	ret = read_nointr(fd, buf, sizeof(buf) - 1);
	686	if (ret >= 0) {
	687	buf[ret] = '\0';
	688	if (safe_uint32(buf, personality, 16) < 0)
	689	return log_error(-1, "Failed to convert personality %s", buf);
	690	}
	691
	692	return ret;
	693	}