1 /* 2 * Copyright (c) 1994 Christos Zoulas 3 * Copyright (c) 1995 Frank van der Linden 4 * Copyright (c) 1995 Scott Bartram 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 * 29 * from: svr4_util.c,v 1.5 1995/01/22 23:44:50 christos Exp 30 * $FreeBSD$ 31 */ 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/namei.h> 36 #include <sys/proc.h> 37 #include <sys/malloc.h> 38 #include <sys/vnode.h> 39 40 #include <machine/stdarg.h> 41 42 #include <compat/linux/linux_util.h> 43 44 const char linux_emul_path[] = "/compat/linux"; 45 46 /* 47 * Search an alternate path before passing pathname arguments on 48 * to system calls. Useful for keeping a separate 'emulation tree'. 49 * 50 * If cflag is set, we check if an attempt can be made to create 51 * the named file, i.e. we check if the directory it should 52 * be in exists. 53 */ 54 int 55 linux_emul_find(td, sgp, path, pbuf, cflag) 56 struct thread *td; 57 caddr_t *sgp; /* Pointer to stackgap memory */ 58 char *path; 59 char **pbuf; 60 int cflag; 61 { 62 char *newpath; 63 size_t sz; 64 int error; 65 66 error = linux_emul_convpath(td, path, (sgp == NULL) ? UIO_SYSSPACE : 67 UIO_USERSPACE, &newpath, cflag); 68 if (newpath == NULL) 69 return (error); 70 71 if (sgp == NULL) { 72 *pbuf = newpath; 73 return (error); 74 } 75 76 sz = strlen(newpath); 77 *pbuf = stackgap_alloc(sgp, sz + 1); 78 if (*pbuf != NULL) 79 error = copyout(newpath, *pbuf, sz + 1); 80 else 81 error = ENAMETOOLONG; 82 free(newpath, M_TEMP); 83 84 return (error); 85 } 86 87 int 88 linux_emul_convpath(td, path, pathseg, pbuf, cflag) 89 struct thread *td; 90 char *path; 91 enum uio_seg pathseg; 92 char **pbuf; 93 int cflag; 94 { 95 struct nameidata nd; 96 struct nameidata ndroot; 97 struct vattr vat; 98 struct vattr vatroot; 99 int error; 100 const char *prefix; 101 char *ptr, *buf, *cp; 102 size_t len, sz; 103 104 buf = (char *) malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 105 *pbuf = buf; 106 107 prefix = linux_emul_path; 108 for (ptr = buf; (*ptr = *prefix) != '\0'; ptr++, prefix++) 109 continue; 110 sz = MAXPATHLEN - (ptr - buf); 111 112 if (pathseg == UIO_SYSSPACE) 113 error = copystr(path, ptr, sz, &len); 114 else 115 error = copyinstr(path, ptr, sz, &len); 116 117 if (error) { 118 *pbuf = NULL; 119 free(buf, M_TEMP); 120 return error; 121 } 122 123 if (*ptr != '/') { 124 error = EINVAL; 125 goto keeporig; 126 } 127 128 /* 129 * We know that there is a / somewhere in this pathname. 130 * Search backwards for it, to find the file's parent dir 131 * to see if it exists in the alternate tree. If it does, 132 * and we want to create a file (cflag is set). We don't 133 * need to worry about the root comparison in this case. 134 */ 135 136 if (cflag) { 137 for (cp = &ptr[len] - 1; *cp != '/'; cp--); 138 *cp = '\0'; 139 140 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, buf, td); 141 error = namei(&nd); 142 *cp = '/'; 143 if (error != 0) 144 goto keeporig; 145 } 146 else { 147 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, buf, td); 148 149 if ((error = namei(&nd)) != 0) 150 goto keeporig; 151 152 /* 153 * We now compare the vnode of the linux_root to the one 154 * vnode asked. If they resolve to be the same, then we 155 * ignore the match so that the real root gets used. 156 * This avoids the problem of traversing "../.." to find the 157 * root directory and never finding it, because "/" resolves 158 * to the emulation root directory. This is expensive :-( 159 */ 160 NDINIT(&ndroot, LOOKUP, FOLLOW, UIO_SYSSPACE, linux_emul_path, 161 td); 162 163 if ((error = namei(&ndroot)) != 0) { 164 /* Cannot happen! */ 165 NDFREE(&nd, NDF_ONLY_PNBUF); 166 vrele(nd.ni_vp); 167 goto keeporig; 168 } 169 170 if ((error = VOP_GETATTR(nd.ni_vp, &vat, td->td_ucred, td)) != 0) { 171 goto bad; 172 } 173 174 if ((error = VOP_GETATTR(ndroot.ni_vp, &vatroot, td->td_ucred, td)) 175 != 0) { 176 goto bad; 177 } 178 179 if (vat.va_fsid == vatroot.va_fsid && 180 vat.va_fileid == vatroot.va_fileid) { 181 error = ENOENT; 182 goto bad; 183 } 184 185 } 186 187 NDFREE(&nd, NDF_ONLY_PNBUF); 188 vrele(nd.ni_vp); 189 if (!cflag) { 190 NDFREE(&ndroot, NDF_ONLY_PNBUF); 191 vrele(ndroot.ni_vp); 192 } 193 return error; 194 195 bad: 196 NDFREE(&ndroot, NDF_ONLY_PNBUF); 197 vrele(ndroot.ni_vp); 198 NDFREE(&nd, NDF_ONLY_PNBUF); 199 vrele(nd.ni_vp); 200 keeporig: 201 /* Keep the original path; copy it back to the start of the buffer. */ 202 bcopy(ptr, buf, len); 203 return error; 204 } 205 206 void 207 linux_msg(const struct thread *td, const char *fmt, ...) 208 { 209 va_list ap; 210 struct proc *p; 211 212 p = td->td_proc; 213 printf("linux: pid %d (%s): ", (int)p->p_pid, p->p_comm); 214 va_start(ap, fmt); 215 vprintf(fmt, ap); 216 va_end(ap); 217 printf("\n"); 218 } 219