mirror of
https://github.com/opencontainers/runc.git
synced 2026-07-10 21:53:57 +08:00
chore(libct/nsenter): extract utility code
...from nsexec.c so they can be used in cloned_binary.c. Signed-off-by: Cory Snider <csnider@mirantis.com>
This commit is contained in:
Cory Snider
committed by
Aleksa Sarai
Aleksa Sarai
parent
164e4bc5f6
commit
35fddfd28f
@@ -0,0 +1,27 @@
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#define _GNU_SOURCE
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#include <errno.h>
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#include <stdlib.h>
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#include "getenv.h"
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#include "log.h"
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int getenv_int(const char *name)
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{
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char *val, *endptr;
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int ret;
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val = getenv(name);
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/* Treat empty value as unset variable. */
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if (val == NULL || *val == '\0')
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return -ENOENT;
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ret = strtol(val, &endptr, 10);
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if (val == endptr || *endptr != '\0')
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bail("unable to parse %s=%s", name, val);
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/*
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* Sanity check: this must be a non-negative number.
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*/
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if (ret < 0)
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bail("bad value for %s=%s (%d)", name, val, ret);
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return ret;
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}
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@@ -0,0 +1,13 @@
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#ifndef NSENTER_GETENV_H
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#define NSENTER_GETENV_H
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/*
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* Returns an environment variable value as a non-negative integer, or -ENOENT
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* if the variable was not found or has an empty value.
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*
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* If the value can not be converted to an integer, or the result is out of
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* range, the function bails out.
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*/
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int getenv_int(const char *name);
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#endif /* NSENTER_GETENV_H */
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@@ -0,0 +1,103 @@
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#define _GNU_SOURCE
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#include <fcntl.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/socket.h>
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#include <unistd.h>
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#include "ipc.h"
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#include "log.h"
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void receive_fd(int sockfd, int new_fd)
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{
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int bytes_read;
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struct msghdr msg = { };
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struct cmsghdr *cmsg;
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struct iovec iov = { };
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char null_byte = '\0';
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int ret;
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int fd_count;
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int *fd_payload;
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iov.iov_base = &null_byte;
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iov.iov_len = 1;
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msg.msg_iov = &iov;
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msg.msg_iovlen = 1;
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msg.msg_controllen = CMSG_SPACE(sizeof(int));
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msg.msg_control = malloc(msg.msg_controllen);
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if (msg.msg_control == NULL) {
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bail("Can't allocate memory to receive fd.");
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}
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memset(msg.msg_control, 0, msg.msg_controllen);
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bytes_read = recvmsg(sockfd, &msg, 0);
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if (bytes_read != 1)
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bail("failed to receive fd from unix socket %d", sockfd);
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if (msg.msg_flags & MSG_CTRUNC)
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bail("received truncated control message from unix socket %d", sockfd);
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cmsg = CMSG_FIRSTHDR(&msg);
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if (!cmsg)
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bail("received message from unix socket %d without control message", sockfd);
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if (cmsg->cmsg_level != SOL_SOCKET)
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bail("received unknown control message from unix socket %d: cmsg_level=%d", sockfd, cmsg->cmsg_level);
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if (cmsg->cmsg_type != SCM_RIGHTS)
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bail("received unknown control message from unix socket %d: cmsg_type=%d", sockfd, cmsg->cmsg_type);
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fd_count = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
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if (fd_count != 1)
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bail("received control message from unix socket %d with too many fds: %d", sockfd, fd_count);
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fd_payload = (int *)CMSG_DATA(cmsg);
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ret = dup3(*fd_payload, new_fd, O_CLOEXEC);
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if (ret < 0)
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bail("cannot dup3 fd %d to %d", *fd_payload, new_fd);
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free(msg.msg_control);
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ret = close(*fd_payload);
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if (ret < 0)
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bail("cannot close fd %d", *fd_payload);
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}
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void send_fd(int sockfd, int fd)
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{
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int bytes_written;
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struct msghdr msg = { };
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struct cmsghdr *cmsg;
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struct iovec iov[1] = { };
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char null_byte = '\0';
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iov[0].iov_base = &null_byte;
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iov[0].iov_len = 1;
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msg.msg_iov = iov;
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msg.msg_iovlen = 1;
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/* We send only one fd as specified by cmsg->cmsg_len below, even
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* though msg.msg_controllen might have more space due to alignment. */
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msg.msg_controllen = CMSG_SPACE(sizeof(int));
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msg.msg_control = malloc(msg.msg_controllen);
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if (msg.msg_control == NULL) {
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bail("Can't allocate memory to send fd.");
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}
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memset(msg.msg_control, 0, msg.msg_controllen);
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cmsg = CMSG_FIRSTHDR(&msg);
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cmsg->cmsg_level = SOL_SOCKET;
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cmsg->cmsg_type = SCM_RIGHTS;
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cmsg->cmsg_len = CMSG_LEN(sizeof(int));
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memcpy(CMSG_DATA(cmsg), &fd, sizeof(int));
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bytes_written = sendmsg(sockfd, &msg, 0);
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free(msg.msg_control);
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if (bytes_written != 1)
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bail("failed to send fd %d via unix socket %d", fd, sockfd);
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}
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@@ -0,0 +1,7 @@
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#ifndef NSENTER_IPC_H
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#define NSENTER_IPC_H
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void receive_fd(int sockfd, int new_fd);
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void send_fd(int sockfd, int fd);
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#endif /* NSENTER_IPC_H */
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@@ -0,0 +1,83 @@
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#define _GNU_SOURCE
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#include <stdarg.h>
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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 <unistd.h>
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#include "log.h"
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#include "getenv.h"
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static const char *level_str[] = { "panic", "fatal", "error", "warning", "info", "debug", "trace" };
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int logfd = -1;
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static int loglevel = DEBUG;
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extern char *escape_json_string(char *str);
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void setup_logpipe(void)
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{
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int i;
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i = getenv_int("_LIBCONTAINER_LOGPIPE");
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if (i < 0) {
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/* We are not runc init, or log pipe was not provided. */
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return;
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}
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logfd = i;
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i = getenv_int("_LIBCONTAINER_LOGLEVEL");
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if (i < 0)
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return;
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loglevel = i;
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}
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/* Defined in nsexec.c */
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extern int current_stage;
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void write_log(int level, const char *format, ...)
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{
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char *message = NULL, *stage = NULL, *json = NULL;
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va_list args;
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int ret;
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if (logfd < 0 || level > loglevel)
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goto out;
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va_start(args, format);
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ret = vasprintf(&message, format, args);
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va_end(args);
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if (ret < 0) {
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message = NULL;
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goto out;
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}
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message = escape_json_string(message);
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if (current_stage < 0) {
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stage = strdup("nsexec");
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if (stage == NULL)
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goto out;
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} else {
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ret = asprintf(&stage, "nsexec-%d", current_stage);
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if (ret < 0) {
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stage = NULL;
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goto out;
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}
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}
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ret = asprintf(&json, "{\"level\":\"%s\", \"msg\": \"%s[%d]: %s\"}\n",
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level_str[level], stage, getpid(), message);
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if (ret < 0) {
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json = NULL;
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goto out;
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}
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/* This logging is on a best-effort basis. In case of a short or failed
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* write there is nothing we can do, so just ignore write() errors.
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*/
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ssize_t __attribute__((unused)) __res = write(logfd, json, ret);
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out:
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free(message);
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free(stage);
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free(json);
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}
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@@ -0,0 +1,37 @@
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#ifndef NSENTER_LOG_H
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#define NSENTER_LOG_H
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#include <stdio.h>
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/*
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* Log levels are the same as in logrus.
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*/
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#define PANIC 0
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#define FATAL 1
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#define ERROR 2
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#define WARNING 3
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#define INFO 4
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#define DEBUG 5
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#define TRACE 6
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/*
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* Sets up logging by getting log fd and log level from the environment,
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* if available.
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*/
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void setup_logpipe(void);
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void write_log(int level, const char *format, ...);
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extern int logfd;
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#define bail(fmt, ...) \
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do { \
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if (logfd < 0) \
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fprintf(stderr, "FATAL: " fmt ": %m\n", \
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##__VA_ARGS__); \
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else \
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write_log(FATAL, fmt ": %m", ##__VA_ARGS__); \
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exit(1); \
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} while(0)
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#endif /* NSENTER_LOG_H */
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@@ -27,11 +27,12 @@
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#include <linux/netlink.h>
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#include <linux/types.h>
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#include "getenv.h"
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#include "ipc.h"
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#include "log.h"
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/* Get all of the CLONE_NEW* flags. */
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#include "namespace.h"
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extern char *escape_json_string(char *str);
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/* Synchronisation values. */
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enum sync_t {
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SYNC_USERMAP_PLS = 0x40, /* Request parent to map our users. */
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@@ -96,22 +97,6 @@ struct nlconfig_t {
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size_t mountsources_len;
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};
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/*
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* Log levels are the same as in logrus.
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*/
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#define PANIC 0
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#define FATAL 1
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#define ERROR 2
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#define WARNING 3
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#define INFO 4
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#define DEBUG 5
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#define TRACE 6
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static const char *level_str[] = { "panic", "fatal", "error", "warning", "info", "debug", "trace" };
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static int logfd = -1;
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static int loglevel = DEBUG;
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/*
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* List of netlink message types sent to us as part of bootstrapping the init.
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* These constants are defined in libcontainer/message_linux.go.
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@@ -149,67 +134,9 @@ int setns(int fd, int nstype)
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}
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#endif
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static void write_log(int level, const char *format, ...)
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{
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char *message = NULL, *stage = NULL, *json = NULL;
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va_list args;
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int ret;
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if (logfd < 0 || level > loglevel)
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goto out;
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va_start(args, format);
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ret = vasprintf(&message, format, args);
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va_end(args);
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if (ret < 0) {
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message = NULL;
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goto out;
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}
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message = escape_json_string(message);
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if (current_stage == STAGE_SETUP) {
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stage = strdup("nsexec");
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if (stage == NULL)
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goto out;
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} else {
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ret = asprintf(&stage, "nsexec-%d", current_stage);
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if (ret < 0) {
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stage = NULL;
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goto out;
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}
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}
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ret = asprintf(&json, "{\"level\":\"%s\", \"msg\": \"%s[%d]: %s\"}\n",
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level_str[level], stage, getpid(), message);
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if (ret < 0) {
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json = NULL;
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goto out;
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}
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/* This logging is on a best-effort basis. In case of a short or failed
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* write there is nothing we can do, so just ignore write() errors.
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*/
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ssize_t __attribute__((unused)) __res = write(logfd, json, ret);
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out:
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free(message);
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free(stage);
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free(json);
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}
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/* XXX: This is ugly. */
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static int syncfd = -1;
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#define bail(fmt, ...) \
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do { \
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if (logfd < 0) \
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fprintf(stderr, "FATAL: " fmt ": %m\n", \
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##__VA_ARGS__); \
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else \
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write_log(FATAL, fmt ": %m", ##__VA_ARGS__); \
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exit(1); \
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} while(0)
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static int write_file(char *data, size_t data_len, char *pathfmt, ...)
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{
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int fd, len, ret = 0;
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@@ -397,56 +324,6 @@ static int clone_parent(jmp_buf *env, int jmpval)
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return clone(child_func, ca.stack_ptr, CLONE_PARENT | SIGCHLD, &ca);
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}
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/*
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* Returns an environment variable value as a non-negative integer, or -ENOENT
|
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* if the variable was not found or has an empty value.
|
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*
|
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* If the value can not be converted to an integer, or the result is out of
|
||||
* range, the function bails out.
|
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*/
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static int getenv_int(const char *name)
|
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{
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char *val, *endptr;
|
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int ret;
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|
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val = getenv(name);
|
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/* Treat empty value as unset variable. */
|
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if (val == NULL || *val == '\0')
|
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return -ENOENT;
|
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|
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ret = strtol(val, &endptr, 10);
|
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if (val == endptr || *endptr != '\0')
|
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bail("unable to parse %s=%s", name, val);
|
||||
/*
|
||||
* Sanity check: this must be a non-negative number.
|
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*/
|
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if (ret < 0)
|
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bail("bad value for %s=%s (%d)", name, val, ret);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
/*
|
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* Sets up logging by getting log fd and log level from the environment,
|
||||
* if available.
|
||||
*/
|
||||
static void setup_logpipe(void)
|
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{
|
||||
int i;
|
||||
|
||||
i = getenv_int("_LIBCONTAINER_LOGPIPE");
|
||||
if (i < 0) {
|
||||
/* We are not runc init, or log pipe was not provided. */
|
||||
return;
|
||||
}
|
||||
logfd = i;
|
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|
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i = getenv_int("_LIBCONTAINER_LOGLEVEL");
|
||||
if (i < 0)
|
||||
return;
|
||||
loglevel = i;
|
||||
}
|
||||
|
||||
/* Returns the clone(2) flag for a namespace, given the name of a namespace. */
|
||||
static int nsflag(char *name)
|
||||
{
|
||||
@@ -645,101 +522,6 @@ static inline int sane_kill(pid_t pid, int signum)
|
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return 0;
|
||||
}
|
||||
|
||||
void receive_fd(int sockfd, int new_fd)
|
||||
{
|
||||
int bytes_read;
|
||||
struct msghdr msg = { };
|
||||
struct cmsghdr *cmsg;
|
||||
struct iovec iov = { };
|
||||
char null_byte = '\0';
|
||||
int ret;
|
||||
int fd_count;
|
||||
int *fd_payload;
|
||||
|
||||
iov.iov_base = &null_byte;
|
||||
iov.iov_len = 1;
|
||||
|
||||
msg.msg_iov = &iov;
|
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msg.msg_iovlen = 1;
|
||||
|
||||
msg.msg_controllen = CMSG_SPACE(sizeof(int));
|
||||
msg.msg_control = malloc(msg.msg_controllen);
|
||||
if (msg.msg_control == NULL) {
|
||||
bail("Can't allocate memory to receive fd.");
|
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}
|
||||
|
||||
memset(msg.msg_control, 0, msg.msg_controllen);
|
||||
|
||||
bytes_read = recvmsg(sockfd, &msg, 0);
|
||||
if (bytes_read != 1)
|
||||
bail("failed to receive fd from unix socket %d", sockfd);
|
||||
if (msg.msg_flags & MSG_CTRUNC)
|
||||
bail("received truncated control message from unix socket %d", sockfd);
|
||||
|
||||
cmsg = CMSG_FIRSTHDR(&msg);
|
||||
if (!cmsg)
|
||||
bail("received message from unix socket %d without control message", sockfd);
|
||||
|
||||
if (cmsg->cmsg_level != SOL_SOCKET)
|
||||
bail("received unknown control message from unix socket %d: cmsg_level=%d", sockfd, cmsg->cmsg_level);
|
||||
|
||||
if (cmsg->cmsg_type != SCM_RIGHTS)
|
||||
bail("received unknown control message from unix socket %d: cmsg_type=%d", sockfd, cmsg->cmsg_type);
|
||||
|
||||
fd_count = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
|
||||
if (fd_count != 1)
|
||||
bail("received control message from unix socket %d with too many fds: %d", sockfd, fd_count);
|
||||
|
||||
fd_payload = (int *)CMSG_DATA(cmsg);
|
||||
ret = dup3(*fd_payload, new_fd, O_CLOEXEC);
|
||||
if (ret < 0)
|
||||
bail("cannot dup3 fd %d to %d", *fd_payload, new_fd);
|
||||
|
||||
free(msg.msg_control);
|
||||
|
||||
ret = close(*fd_payload);
|
||||
if (ret < 0)
|
||||
bail("cannot close fd %d", *fd_payload);
|
||||
}
|
||||
|
||||
void send_fd(int sockfd, int fd)
|
||||
{
|
||||
int bytes_written;
|
||||
struct msghdr msg = { };
|
||||
struct cmsghdr *cmsg;
|
||||
struct iovec iov[1] = { };
|
||||
char null_byte = '\0';
|
||||
|
||||
iov[0].iov_base = &null_byte;
|
||||
iov[0].iov_len = 1;
|
||||
|
||||
msg.msg_iov = iov;
|
||||
msg.msg_iovlen = 1;
|
||||
|
||||
/* We send only one fd as specified by cmsg->cmsg_len below, even
|
||||
* though msg.msg_controllen might have more space due to alignment. */
|
||||
msg.msg_controllen = CMSG_SPACE(sizeof(int));
|
||||
msg.msg_control = malloc(msg.msg_controllen);
|
||||
if (msg.msg_control == NULL) {
|
||||
bail("Can't allocate memory to send fd.");
|
||||
}
|
||||
|
||||
memset(msg.msg_control, 0, msg.msg_controllen);
|
||||
|
||||
cmsg = CMSG_FIRSTHDR(&msg);
|
||||
cmsg->cmsg_level = SOL_SOCKET;
|
||||
cmsg->cmsg_type = SCM_RIGHTS;
|
||||
cmsg->cmsg_len = CMSG_LEN(sizeof(int));
|
||||
memcpy(CMSG_DATA(cmsg), &fd, sizeof(int));
|
||||
|
||||
bytes_written = sendmsg(sockfd, &msg, 0);
|
||||
|
||||
free(msg.msg_control);
|
||||
|
||||
if (bytes_written != 1)
|
||||
bail("failed to send fd %d via unix socket %d", fd, sockfd);
|
||||
}
|
||||
|
||||
void receive_mountsources(int sockfd)
|
||||
{
|
||||
char *mount_fds, *endp;
|
||||
|
||||
Reference in New Issue
Block a user