From d960371482d75711e61896f27ea0d3740ea69fe0 Mon Sep 17 00:00:00 2001 From: David Herrmann Date: Tue, 22 Sep 2015 14:09:54 +0200 Subject: util: introduce {send,receive}_one_fd() Introduce two new helpers that send/receive a single fd via a unix transport. Also make nspawn use them instead of hard-coding it. Based on a patch by Krzesimir Nowak. --- src/nspawn/nspawn-expose-ports.c | 48 ++++++---------------------------------- 1 file changed, 7 insertions(+), 41 deletions(-) (limited to 'src/nspawn/nspawn-expose-ports.c') diff --git a/src/nspawn/nspawn-expose-ports.c b/src/nspawn/nspawn-expose-ports.c index 38250b6e02..9e63d88b69 100644 --- a/src/nspawn/nspawn-expose-ports.c +++ b/src/nspawn/nspawn-expose-ports.c @@ -183,17 +183,8 @@ int expose_port_execute(sd_netlink *rtnl, ExposePort *l, union in_addr_union *ex } int expose_port_send_rtnl(int send_fd) { - union { - struct cmsghdr cmsghdr; - uint8_t buf[CMSG_SPACE(sizeof(int))]; - } control = {}; - struct msghdr mh = { - .msg_control = &control, - .msg_controllen = sizeof(control), - }; - struct cmsghdr *cmsg; _cleanup_close_ int fd = -1; - ssize_t k; + int r; assert(send_fd >= 0); @@ -201,19 +192,11 @@ int expose_port_send_rtnl(int send_fd) { if (fd < 0) return log_error_errno(errno, "Failed to allocate container netlink: %m"); - cmsg = CMSG_FIRSTHDR(&mh); - cmsg->cmsg_level = SOL_SOCKET; - cmsg->cmsg_type = SCM_RIGHTS; - cmsg->cmsg_len = CMSG_LEN(sizeof(int)); - memcpy(CMSG_DATA(cmsg), &fd, sizeof(int)); - - mh.msg_controllen = cmsg->cmsg_len; - /* Store away the fd in the socket, so that it stays open as * long as we run the child */ - k = sendmsg(send_fd, &mh, MSG_NOSIGNAL); - if (k < 0) - return log_error_errno(errno, "Failed to send netlink fd: %m"); + r = send_one_fd(send_fd, fd); + if (r < 0) + return log_error_errno(r, "Failed to send netlink fd: %m"); return 0; } @@ -224,33 +207,16 @@ int expose_port_watch_rtnl( sd_netlink_message_handler_t handler, union in_addr_union *exposed, sd_netlink **ret) { - - union { - struct cmsghdr cmsghdr; - uint8_t buf[CMSG_SPACE(sizeof(int))]; - } control = {}; - struct msghdr mh = { - .msg_control = &control, - .msg_controllen = sizeof(control), - }; - struct cmsghdr *cmsg; _cleanup_netlink_unref_ sd_netlink *rtnl = NULL; int fd, r; - ssize_t k; assert(event); assert(recv_fd >= 0); assert(ret); - k = recvmsg(recv_fd, &mh, MSG_NOSIGNAL); - if (k < 0) - return log_error_errno(errno, "Failed to recv netlink fd: %m"); - - cmsg = CMSG_FIRSTHDR(&mh); - assert(cmsg->cmsg_level == SOL_SOCKET); - assert(cmsg->cmsg_type == SCM_RIGHTS); - assert(cmsg->cmsg_len == CMSG_LEN(sizeof(int))); - memcpy(&fd, CMSG_DATA(cmsg), sizeof(int)); + fd = receive_one_fd(recv_fd); + if (fd < 0) + return log_error_errno(fd, "Failed to recv netlink fd: %m"); r = sd_netlink_open_fd(&rtnl, fd); if (r < 0) { -- cgit v1.2.3-54-g00ecf