From 1b911148009f696717da0b676d6d10af85d5aefb Mon Sep 17 00:00:00 2001 From: Emilio Pozuelo Monfort Date: Sat, 17 Jul 2010 22:09:13 +0200 Subject: [PATCH] Add support to send file descriptors over Unix sockets --- sysdeps/mach/hurd/recvmsg.c | 105 ++++++++++++++++++++++++++++++++++++++++++-- sysdeps/mach/hurd/sendmsg.c | 73 +++++++++++++++++++++++++----- 2 files changed, 163 insertions(+), 15 deletions(-) --- a/sysdeps/mach/hurd/recvmsg.c +++ b/sysdeps/mach/hurd/recvmsg.c @@ -32,13 +32,33 @@ addr_port_t aport; char *data = NULL; mach_msg_type_number_t len = 0; - mach_port_t *ports; + mach_port_t *ports, *newports; mach_msg_type_number_t nports = 0; + struct cmsghdr *cmsg; char *cdata = NULL; mach_msg_type_number_t clen = 0; size_t amount; char *buf; - int i; + int nfds, *fds; + int i, j; + + error_t reauthenticate (mach_port_t port, mach_port_t *result) + { + error_t err; + mach_port_t ref; + ref = __mach_reply_port (); + do + err = __io_reauthenticate (port, ref, MACH_MSG_TYPE_MAKE_SEND); + while (err == EINTR); + if (!err) + do + err = __USEPORT (AUTH, __auth_user_authenticate (port, + ref, MACH_MSG_TYPE_MAKE_SEND, + result)); + while (err == EINTR); + __mach_port_destroy (__mach_task_self (), ref); + return err; + } /* Find the total number of bytes to be read. */ amount = 0; @@ -135,6 +155,85 @@ message->msg_controllen = clen; memcpy (message->msg_control, cdata, message->msg_controllen); + /* SCM_RIGHTS ports. */ + if (nports > 0) + { + newports = __alloca (nports * sizeof (mach_port_t)); + + /* Reauthenticate all ports here. */ + for (i = 0; i < nports; i++) + { + err = reauthenticate (ports[i], &newports[i]); + __mach_port_deallocate (__mach_task_self (), ports[i]); + if (err) + { + for (j = 0; j < i; j++) + __mach_port_deallocate (__mach_task_self (), newports[j]); + for (j = i+1; j < nports; j++) + __mach_port_deallocate (__mach_task_self (), ports[j]); + + __vm_deallocate (__mach_task_self (), (vm_address_t) cdata, clen); + __hurd_fail (err); + } + } + + j = 0; + for (cmsg = CMSG_FIRSTHDR (message); + cmsg; + cmsg = CMSG_NXTHDR (message, cmsg)) + { + if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) + { + fds = (int *) CMSG_DATA (cmsg); + nfds = (cmsg->cmsg_len - CMSG_ALIGN (sizeof (struct cmsghdr))) + / sizeof (int); + + for (i = 0; i < nfds && j < nports; i++) + { + /* The fd's flags are passed in the control data. */ + fds[i] = _hurd_intern_fd (newports[j++], fds[i], 0); + if (fds[i] == -1) + { + err = errno; + goto cleanup; + } + } + } + } + + if (j != nports) + err = EGRATUITOUS; + + if (err) + cleanup: + { + /* Clean up all the file descriptors. */ + nports = j; + j = 0; + for (cmsg = CMSG_FIRSTHDR (message); + cmsg; + cmsg = CMSG_NXTHDR (message, cmsg)) + { + if (cmsg->cmsg_level == SOL_SOCKET + && cmsg->cmsg_type == SCM_RIGHTS) + { + fds = (int *) CMSG_DATA (cmsg); + nfds = (cmsg->cmsg_len + - CMSG_ALIGN (sizeof (struct cmsghdr))) + / sizeof (int); + for (i = 0; i < nfds && j < nports; i++, j++) + _hurd_fd_close (_hurd_fd_get (fds[i])); + } + } + + for (; j < nports; j++) + __mach_port_deallocate (__mach_task_self (), newports[j]); + + __vm_deallocate (__mach_task_self (), (vm_address_t) cdata, clen); + __hurd_fail (err); + } + } + __vm_deallocate (__mach_task_self (), (vm_address_t) cdata, clen); return (buf - data); --- a/sysdeps/mach/hurd/sendmsg.c +++ b/sysdeps/mach/hurd/sendmsg.c @@ -31,6 +31,10 @@ __libc_sendmsg (int fd, const struct msghdr *message, int flags) { error_t err = 0; + struct cmsghdr *cmsg; + mach_port_t *ports = NULL; + mach_msg_type_number_t nports = 0; + int *fds, nfds; struct sockaddr_un *addr = message->msg_name; socklen_t addr_len = message->msg_namelen; addr_port_t aport = MACH_PORT_NULL; @@ -43,6 +47,7 @@ mach_msg_type_number_t len; mach_msg_type_number_t amount; int dealloc = 0; + int socketrpc = 0; int i; /* Find the total number of bytes to be written. */ @@ -100,6 +105,47 @@ } } + /* SCM_RIGHTS support: get the number of fds to send. */ + cmsg = CMSG_FIRSTHDR (message); + for (; cmsg; cmsg = CMSG_NXTHDR (message, cmsg)) + if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) + nports += (cmsg->cmsg_len - CMSG_ALIGN (sizeof (struct cmsghdr))) + / sizeof (int); + + if (nports) + ports = __alloca (nports * sizeof (mach_port_t)); + + nports = 0; + for (cmsg = CMSG_FIRSTHDR (message); + cmsg; + cmsg = CMSG_NXTHDR (message, cmsg)) + { + if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) + { + fds = (int *) CMSG_DATA (cmsg); + nfds = (cmsg->cmsg_len - CMSG_ALIGN (sizeof (struct cmsghdr))) + / sizeof (int); + + for (i = 0; i < nfds; i++) + { + err = HURD_DPORT_USE + (fds[i], + ({ + err = __io_restrict_auth (port, &ports[nports], + 0, 0, 0, 0); + if (! err) + nports++; + /* We pass the flags in the control data. */ + fds[i] = descriptor->flags; + err; + })); + + if (err) + goto out; + } + } + } + if (addr) { if (addr->sun_family == AF_LOCAL) @@ -109,9 +154,8 @@ file_t file = __file_name_lookup (addr->sun_path, 0, 0); if (file == MACH_PORT_NULL) { - if (dealloc) - __vm_deallocate (__mach_task_self (), data.addr, len); - return -1; + err = errno; + goto out; } err = __ifsock_getsockaddr (file, &aport); __mach_port_deallocate (__mach_task_self (), file); @@ -119,11 +163,7 @@ /* The file did not grok the ifsock protocol. */ err = ENOTSOCK; if (err) - { - if (dealloc) - __vm_deallocate (__mach_task_self (), data.addr, len); - return __hurd_fail (err); - } + goto out; } else err = EIEIO; @@ -142,8 +182,9 @@ /* Send the data. */ err = __socket_send (port, aport, flags, data.ptr, len, - NULL, - MACH_MSG_TYPE_COPY_SEND, 0, + ports, + MACH_MSG_TYPE_COPY_SEND, + nports, message->msg_control, message->msg_controllen, &amount); @@ -152,11 +193,19 @@ } err; })); + socketrpc = 1; + + out: + for (i = 0; i < nports; i++) + __mach_port_deallocate (__mach_task_self (), ports[i]); if (dealloc) __vm_deallocate (__mach_task_self (), data.addr, len); - return err ? __hurd_sockfail (fd, flags, err) : amount; + if (socketrpc) + return err ? __hurd_sockfail (fd, flags, err) : amount; + else + return __hurd_fail (err); } weak_alias (__libc_sendmsg, sendmsg)