1 | /* Copyright (C) 2001-2024 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | |
4 | The GNU C Library is free software; you can redistribute it and/or |
5 | modify it under the terms of the GNU Lesser General Public License as |
6 | published by the Free Software Foundation; either version 2.1 of the |
7 | License, or (at your option) any later version. |
8 | |
9 | The GNU C Library is distributed in the hope that it will be useful, |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | Lesser General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU Lesser General Public |
15 | License along with the GNU C Library; see the file COPYING.LIB. If |
16 | not, see <https://www.gnu.org/licenses/>. */ |
17 | |
18 | #include <errno.h> |
19 | #include <string.h> |
20 | #include <sys/socket.h> |
21 | |
22 | #include <hurd.h> |
23 | #include <hurd/fd.h> |
24 | #include <hurd/socket.h> |
25 | #include <sysdep-cancel.h> |
26 | |
27 | /* Receive a message as described by MESSAGE from socket FD. |
28 | Returns the number of bytes read or -1 for errors. */ |
29 | ssize_t |
30 | __libc_recvmsg (int fd, struct msghdr *message, int flags) |
31 | { |
32 | error_t err; |
33 | addr_port_t aport; |
34 | char *data = NULL; |
35 | mach_msg_type_number_t len = 0; |
36 | mach_port_t *ports, *newports = NULL; |
37 | mach_msg_type_number_t nports = 0; |
38 | struct cmsghdr *cmsg; |
39 | char *cdata = NULL; |
40 | mach_msg_type_number_t clen = 0; |
41 | size_t amount; |
42 | char *buf; |
43 | int nfds, *opened_fds = NULL; |
44 | int i, ii, j; |
45 | int newfds; |
46 | int cancel_oldtype; |
47 | |
48 | error_t reauthenticate (mach_port_t port, mach_port_t *result) |
49 | { |
50 | error_t err; |
51 | mach_port_t ref; |
52 | ref = __mach_reply_port (); |
53 | int cancel_oldtype; |
54 | |
55 | cancel_oldtype = LIBC_CANCEL_ASYNC(); |
56 | do |
57 | err = __io_reauthenticate (port, ref, MACH_MSG_TYPE_MAKE_SEND); |
58 | while (err == EINTR); |
59 | if (!err) |
60 | do |
61 | err = __USEPORT_CANCEL (AUTH, __auth_user_authenticate (port, |
62 | ref, MACH_MSG_TYPE_MAKE_SEND, |
63 | result)); |
64 | while (err == EINTR); |
65 | LIBC_CANCEL_RESET (cancel_oldtype); |
66 | |
67 | __mach_port_destroy (__mach_task_self (), ref); |
68 | return err; |
69 | } |
70 | |
71 | /* Find the total number of bytes to be read. */ |
72 | amount = 0; |
73 | for (i = 0; i < message->msg_iovlen; i++) |
74 | { |
75 | amount += message->msg_iov[i].iov_len; |
76 | |
77 | /* As an optimization, we set the initial values of DATA and LEN |
78 | from the first non-empty iovec. This kicks-in in the case |
79 | where the whole packet fits into that iovec buffer. */ |
80 | if (data == NULL && message->msg_iov[i].iov_len > 0) |
81 | { |
82 | data = message->msg_iov[i].iov_base; |
83 | len = message->msg_iov[i].iov_len; |
84 | } |
85 | } |
86 | |
87 | buf = data; |
88 | cancel_oldtype = LIBC_CANCEL_ASYNC(); |
89 | err = HURD_DPORT_USE_CANCEL (fd, __socket_recv (port, &aport, |
90 | flags, &data, &len, |
91 | &ports, &nports, |
92 | &cdata, &clen, |
93 | &message->msg_flags, amount)); |
94 | LIBC_CANCEL_RESET (cancel_oldtype); |
95 | if (err) |
96 | return __hurd_sockfail (fd, flags, err); |
97 | |
98 | if (message->msg_name != NULL && aport != MACH_PORT_NULL) |
99 | { |
100 | char *buf = message->msg_name; |
101 | mach_msg_type_number_t buflen = message->msg_namelen; |
102 | int type; |
103 | |
104 | cancel_oldtype = LIBC_CANCEL_ASYNC(); |
105 | err = __socket_whatis_address (aport, &type, &buf, &buflen); |
106 | LIBC_CANCEL_RESET (cancel_oldtype); |
107 | |
108 | if (err == EOPNOTSUPP) |
109 | /* If the protocol server can't tell us the address, just return a |
110 | zero-length one. */ |
111 | { |
112 | buf = message->msg_name; |
113 | buflen = 0; |
114 | err = 0; |
115 | } |
116 | |
117 | if (err) |
118 | { |
119 | __mach_port_deallocate (__mach_task_self (), aport); |
120 | return __hurd_sockfail (fd, flags, err); |
121 | } |
122 | |
123 | if (message->msg_namelen > buflen) |
124 | message->msg_namelen = buflen; |
125 | |
126 | if (buf != message->msg_name) |
127 | { |
128 | memcpy (message->msg_name, buf, message->msg_namelen); |
129 | __vm_deallocate (__mach_task_self (), (vm_address_t) buf, buflen); |
130 | } |
131 | |
132 | if (buflen > 0) |
133 | ((struct sockaddr *) message->msg_name)->sa_family = type; |
134 | } |
135 | else if (message->msg_name != NULL) |
136 | message->msg_namelen = 0; |
137 | |
138 | if (MACH_PORT_VALID (aport)) |
139 | __mach_port_deallocate (__mach_task_self (), aport); |
140 | |
141 | if (buf == data) |
142 | buf += len; |
143 | else |
144 | { |
145 | /* Copy the data into MSG. */ |
146 | if (len > amount) |
147 | message->msg_flags |= MSG_TRUNC; |
148 | else |
149 | amount = len; |
150 | |
151 | buf = data; |
152 | for (i = 0; i < message->msg_iovlen; i++) |
153 | { |
154 | #define min(a, b) ((a) > (b) ? (b) : (a)) |
155 | size_t copy = min (message->msg_iov[i].iov_len, amount); |
156 | |
157 | memcpy (message->msg_iov[i].iov_base, buf, copy); |
158 | |
159 | buf += copy; |
160 | amount -= copy; |
161 | if (len == 0) |
162 | break; |
163 | } |
164 | |
165 | __vm_deallocate (__mach_task_self (), (vm_address_t) data, len); |
166 | } |
167 | |
168 | /* Copy the control message into MSG. */ |
169 | if (clen > message->msg_controllen) |
170 | message->msg_flags |= MSG_CTRUNC; |
171 | else |
172 | message->msg_controllen = clen; |
173 | memcpy (message->msg_control, cdata, message->msg_controllen); |
174 | |
175 | if (nports > 0) |
176 | { |
177 | newports = __alloca (nports * sizeof (mach_port_t)); |
178 | opened_fds = __alloca (nports * sizeof (int)); |
179 | } |
180 | |
181 | /* This counts how many ports we processed completely. */ |
182 | i = 0; |
183 | /* This counts how many new fds we create. */ |
184 | newfds = 0; |
185 | |
186 | for (cmsg = CMSG_FIRSTHDR (message); |
187 | cmsg; |
188 | cmsg = CMSG_NXTHDR (message, cmsg)) |
189 | { |
190 | if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) |
191 | { |
192 | /* SCM_RIGHTS support. */ |
193 | /* The fd's flags are passed in the control data. */ |
194 | int *fds = (int *) CMSG_DATA (cmsg); |
195 | nfds = (cmsg->cmsg_len - CMSG_ALIGN (sizeof (struct cmsghdr))) |
196 | / sizeof (int); |
197 | |
198 | for (j = 0; j < nfds; j++) |
199 | { |
200 | int fd_flags = (flags & MSG_CMSG_CLOEXEC) ? O_CLOEXEC : 0; |
201 | err = reauthenticate (ports[i], &newports[newfds]); |
202 | if (err) |
203 | goto cleanup; |
204 | /* We do not currently take any flag from the sender. */ |
205 | fds[j] = opened_fds[newfds] = _hurd_intern_fd (newports[newfds], |
206 | (fds[j] & 0) |
207 | | fd_flags, |
208 | 0); |
209 | if (fds[j] == -1) |
210 | { |
211 | err = errno; |
212 | __mach_port_deallocate (__mach_task_self (), newports[newfds]); |
213 | goto cleanup; |
214 | } |
215 | i++; |
216 | newfds++; |
217 | } |
218 | } |
219 | } |
220 | |
221 | for (i = 0; i < nports; i++) |
222 | __mach_port_deallocate (mach_task_self (), ports[i]); |
223 | |
224 | __vm_deallocate (__mach_task_self (), (vm_address_t) cdata, clen); |
225 | |
226 | return (buf - data); |
227 | |
228 | cleanup: |
229 | /* Clean up all the file descriptors from port 0 to i-1. */ |
230 | if (nports > 0) |
231 | { |
232 | ii = 0; |
233 | newfds = 0; |
234 | for (cmsg = CMSG_FIRSTHDR (message); |
235 | cmsg; |
236 | cmsg = CMSG_NXTHDR (message, cmsg)) |
237 | { |
238 | if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) |
239 | { |
240 | nfds = (cmsg->cmsg_len - CMSG_ALIGN (sizeof (struct cmsghdr))) |
241 | / sizeof (int); |
242 | for (j = 0; j < nfds && ii < i; j++, ii++, newfds++) |
243 | { |
244 | _hurd_fd_close (_hurd_fd_get (opened_fds[newfds])); |
245 | __mach_port_deallocate (__mach_task_self (), newports[newfds]); |
246 | __mach_port_deallocate (__mach_task_self (), ports[ii]); |
247 | } |
248 | } |
249 | } |
250 | } |
251 | |
252 | __vm_deallocate (__mach_task_self (), (vm_address_t) cdata, clen); |
253 | return __hurd_fail (err); |
254 | } |
255 | |
256 | weak_alias (__libc_recvmsg, recvmsg) |
257 | weak_alias (__libc_recvmsg, __recvmsg) |
258 | |