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759ef658 | 1 | /* -*-c-*- |
2 | * | |
1a6043f9 | 3 | * $Id$ |
759ef658 | 4 | * |
5 | * File descriptor passing | |
6 | * | |
7 | * (c) 2003 Straylight/Edgeware | |
8 | */ | |
9 | ||
d4efbcd9 | 10 | /*----- Licensing notice --------------------------------------------------* |
759ef658 | 11 | * |
12 | * This file is part of the mLib utilities library. | |
13 | * | |
14 | * mLib is free software; you can redistribute it and/or modify | |
15 | * it under the terms of the GNU Library General Public License as | |
16 | * published by the Free Software Foundation; either version 2 of the | |
17 | * License, or (at your option) any later version. | |
d4efbcd9 | 18 | * |
759ef658 | 19 | * mLib is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
22 | * GNU Library General Public License for more details. | |
d4efbcd9 | 23 | * |
759ef658 | 24 | * You should have received a copy of the GNU Library General Public |
25 | * License along with mLib; if not, write to the Free | |
26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, | |
27 | * MA 02111-1307, USA. | |
28 | */ | |
29 | ||
759ef658 | 30 | /*----- Header files ------------------------------------------------------*/ |
31 | ||
b3a0ac5e MW |
32 | #include "config.h" |
33 | ||
759ef658 | 34 | #include <errno.h> |
35 | #include <stdio.h> | |
36 | #include <stdlib.h> | |
37 | #include <string.h> | |
38 | ||
39 | #include <sys/types.h> | |
40 | #include <sys/time.h> | |
41 | #include <unistd.h> | |
42 | #include <sys/socket.h> | |
43 | #include <sys/uio.h> | |
44 | #include <sys/un.h> | |
45 | ||
46 | #include "fdpass.h" | |
47 | ||
48 | /*----- Main code ---------------------------------------------------------*/ | |
49 | ||
50 | /* --- @fdpass_send@ --- * | |
51 | * | |
52 | * Arguments: @int sock@ = socket to send over | |
53 | * @int fd@ = file descriptor to send | |
54 | * @const void *p@ = pointer to data to send | |
55 | * @size_t sz@ = size of buffer to send | |
56 | * | |
57 | * Returns: On error, @-1@, otherwise number of bytes transferred from | |
58 | * @p@. | |
59 | * | |
60 | * Use: Sends a copy of file descriptor @fd@ to the other end of | |
61 | * @sock@. | |
62 | */ | |
63 | ||
64 | ssize_t fdpass_send(int sock, int fd, const void *p, size_t sz) | |
65 | { | |
66 | struct iovec iov; | |
67 | struct msghdr msg; | |
68 | #ifndef HAVE_MSG_ACCRIGHTS | |
69 | char buf[CMSG_SPACE(sizeof(fd))]; | |
70 | struct cmsghdr *cmsg; | |
71 | #endif | |
72 | ||
73 | iov.iov_base = (/*unconst*/ void *)p; | |
74 | iov.iov_len = sz; | |
75 | msg.msg_name = 0; | |
76 | msg.msg_namelen = 0; | |
77 | msg.msg_iov = &iov; | |
78 | msg.msg_iovlen = 1; | |
759ef658 | 79 | #ifdef HAVE_MSG_ACCRIGHTS |
80 | msg.msg_accrights = &fd; | |
81 | msg.msg_accrightslen = sizeof(fd); | |
d4efbcd9 | 82 | #else |
1a6043f9 | 83 | msg.msg_flags = 0; |
759ef658 | 84 | msg.msg_control = buf; |
85 | msg.msg_controllen = sizeof(buf); | |
86 | cmsg = CMSG_FIRSTHDR(&msg); | |
87 | cmsg->cmsg_len = CMSG_LEN(sizeof(fd)); | |
88 | cmsg->cmsg_level = SOL_SOCKET; | |
89 | cmsg->cmsg_type = SCM_RIGHTS; | |
90 | memcpy(CMSG_DATA(cmsg), &fd, sizeof(fd)); | |
91 | #endif | |
92 | return (sendmsg(sock, &msg, 0)); | |
93 | } | |
94 | ||
95 | /* --- @fdpass_recv@ --- * | |
96 | * | |
97 | * Arguments: @int sock@ = socket to send over | |
98 | * @int *fd@ = where to put received descriptor | |
99 | * @void *p@ = pointer to where to put data | |
100 | * @size_t sz@ = size of buffer | |
101 | * | |
102 | * Returns: On error, @-1@, otherwise number of bytes transferred. | |
103 | * | |
104 | * Use: Receives a file descriptor. If the call succeeds, and there | |
105 | * was a file descriptor, then @fd@ won't be @-1@ on exit; | |
106 | * otherwise it will. At most one descriptor will be collected. | |
107 | */ | |
108 | ||
109 | ssize_t fdpass_recv(int sock, int *fd, void *p, size_t sz) | |
110 | { | |
111 | struct iovec iov; | |
112 | struct msghdr msg; | |
113 | ssize_t rc; | |
114 | #ifndef HAVE_MSG_ACCRIGHTS | |
115 | char buf[CMSG_SPACE(sizeof(fd))]; | |
116 | struct cmsghdr *cmsg; | |
117 | int fdtmp; | |
118 | #endif | |
119 | ||
120 | *fd = -1; | |
121 | iov.iov_base = p; | |
122 | iov.iov_len = sz; | |
123 | msg.msg_name = 0; | |
124 | msg.msg_namelen = 0; | |
125 | msg.msg_iov = &iov; | |
126 | msg.msg_iovlen = 1; | |
759ef658 | 127 | #ifdef HAVE_MSG_ACCRIGHTS |
128 | msg.msg_accrights = fd; | |
129 | msg.msg_accrightslen = sizeof(*fd); | |
130 | #else | |
1a6043f9 | 131 | msg.msg_flags = 0; |
759ef658 | 132 | msg.msg_control = buf; |
133 | msg.msg_controllen = sizeof(buf); | |
134 | #endif | |
135 | if ((rc = recvmsg(sock, &msg, 0)) < 0) | |
136 | return (rc); | |
137 | #ifdef HAVE_MSG_ACCRIGHTS | |
138 | if (msg.msg_accrightslen < sizeof(*fd)) | |
139 | *fd = -1; | |
140 | #else | |
141 | for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) { | |
142 | if (cmsg->cmsg_level == SOL_SOCKET && | |
143 | cmsg->cmsg_type == SCM_RIGHTS && | |
d4efbcd9 | 144 | cmsg->cmsg_len >= CMSG_LEN(sizeof(fd))) { |
759ef658 | 145 | memcpy(&fdtmp, CMSG_DATA(cmsg), sizeof(fdtmp)); |
146 | if (*fd == -1) | |
147 | *fd = fdtmp; | |
148 | else | |
149 | close(fdtmp); | |
150 | } | |
151 | } | |
152 | #endif | |
153 | return (rc); | |
154 | } | |
155 | ||
156 | /*----- That's all, folks -------------------------------------------------*/ |