upstream/mercurial-mirror Files · rust/chg/src/sendfds.c

rhg: use `Command::exec` instead of `Command::status`...

rhg: use `Command::exec` instead of `Command::status` `rhg` is supposed to be a transparent executable, using a subprocess defeats that purpose. See inline comments for more details. This also introduces the `which` crate to check if the fallback executable actually exists to help debugging (plain `execve` doesn't give much information). The error code 253 is used to signify that the fallback is not found, but may mean in the future that it is otherwise invalid if we start being more specific. Differential Revision: https://phab.mercurial-scm.org/D12578

Yuya Nishihara - - Load All Authors

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      /*

       * Utility to send fds via Unix domain socket

       *

       * Copyright 2011, 2018 Yuya Nishihara <yuya@tcha.org>

       *

       * This software may be used and distributed according to the terms of the

       * GNU General Public License version 2 or any later version.

       */

      #include <errno.h>

      #include <stdlib.h>

      #include <string.h>

      #include <sys/socket.h>

      #include <sys/types.h>

      #define MAX_FD_LEN 10

      /*

       * Sends the given fds with 1-byte dummy payload.

       *

       * Returns the number of bytes sent on success, -1 on error and errno is set

       * appropriately.

       */

      ssize_t sendfds(int sockfd, const int *fds, size_t fdlen)

      {

      	char dummy[1] = {0};

      	struct iovec iov = {dummy, sizeof(dummy)};

      	char fdbuf[CMSG_SPACE(sizeof(fds[0]) * MAX_FD_LEN)];

      	struct msghdr msgh;

      	struct cmsghdr *cmsg;

      	/* just use a fixed-size buffer since we'll never send tons of fds */

      	if (fdlen > MAX_FD_LEN) {

      		errno = EINVAL;

      		return -1;

      	}

      	memset(&msgh, 0, sizeof(msgh));

      	msgh.msg_iov = &iov;

      	msgh.msg_iovlen = 1;

      	msgh.msg_control = fdbuf;

      	msgh.msg_controllen = CMSG_SPACE(sizeof(fds[0]) * fdlen);

      	cmsg = CMSG_FIRSTHDR(&msgh);

      	cmsg->cmsg_level = SOL_SOCKET;

      	cmsg->cmsg_type = SCM_RIGHTS;

      	cmsg->cmsg_len = CMSG_LEN(sizeof(fds[0]) * fdlen);

      	memcpy(CMSG_DATA(cmsg), fds, sizeof(fds[0]) * fdlen);

      	msgh.msg_controllen = cmsg->cmsg_len;

      	return sendmsg(sockfd, &msgh, 0);

      }

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				/*
				* Utility to send fds via Unix domain socket
				*
				* Copyright 2011, 2018 Yuya Nishihara <yuya@tcha.org>
				*
				* This software may be used and distributed according to the terms of the
				* GNU General Public License version 2 or any later version.
				*/

				#include <errno.h>
				#include <stdlib.h>
				#include <string.h>
				#include <sys/socket.h>
				#include <sys/types.h>

				#define MAX_FD_LEN 10

				/*
				* Sends the given fds with 1-byte dummy payload.
				*
				* Returns the number of bytes sent on success, -1 on error and errno is set
				* appropriately.
				*/
				ssize_t sendfds(int sockfd, const int *fds, size_t fdlen)
				{
				char dummy[1] = {0};
				struct iovec iov = {dummy, sizeof(dummy)};
				char fdbuf[CMSG_SPACE(sizeof(fds[0]) * MAX_FD_LEN)];
				struct msghdr msgh;
				struct cmsghdr *cmsg;

				/* just use a fixed-size buffer since we'll never send tons of fds */
				if (fdlen > MAX_FD_LEN) {
				errno = EINVAL;
				return -1;
				}

				memset(&msgh, 0, sizeof(msgh));
				msgh.msg_iov = &iov;
				msgh.msg_iovlen = 1;
				msgh.msg_control = fdbuf;
				msgh.msg_controllen = CMSG_SPACE(sizeof(fds[0]) * fdlen);

				cmsg = CMSG_FIRSTHDR(&msgh);
				cmsg->cmsg_level = SOL_SOCKET;
				cmsg->cmsg_type = SCM_RIGHTS;
				cmsg->cmsg_len = CMSG_LEN(sizeof(fds[0]) * fdlen);
				memcpy(CMSG_DATA(cmsg), fds, sizeof(fds[0]) * fdlen);
				msgh.msg_controllen = cmsg->cmsg_len;
				return sendmsg(sockfd, &msgh, 0);
				}