src/sys/rmtsysc.c

   1 /*
   2  * Copyright 2000, International Business Machines Corporation and others.
   3  * All Rights Reserved.
   4  *
   5  * This software has been released under the terms of the IBM Public
   6  * License.  For details, see the LICENSE file in the top-level source
   7  * directory or online at http://www.openafs.org/dl/license10.html
   8  */
   9
  10 /*
  11  * This module (residing in lib/afs/librmtsys.a) implements the client side of
  12  * the rpc version (via rx) of non-standard system calls. Currently only rpc
  13  * calls of setpag, and pioctl are supported.
  14  */
  15 #include <afsconfig.h>
  16 #include <afs/param.h>
  17
  18 #include <roken.h>
  19
  20 #include <limits.h>
  21
  22 #include <afs/vice.h>
  23 #include <rx/xdr.h>
  24
  25 #include "rmtsys.h"
  26 #include "sys_prototypes.h"
  27
  28
  29 #define NOPAG       0xffffffff  /* Also defined in afs/afs.h */
  30 static afs_int32 hostAddr = 0;
  31 static int hostAddrLookup = 0;
  32 char *afs_server = 0, server_name[128];
  33 static afs_int32 SetClientCreds(struct clientcred *creds, afs_uint32 * groups);
  34 int afs_get_pag_from_groups(afs_uint32 g0, afs_uint32 g1);
  35 void afs_get_groups_from_pag(afs_uint32 pag, afs_uint32 * g0p, afs_uint32 * g1p);
  36
  37 /* Picks up the name of the remote afs client host where the rmtsys
  38  * daemon resides. Since the clients may be diskless and/or readonly
  39  * ones we felt it's better to rely on an shell environment
  40  * (AFSSERVER) for the host name first. If that is not set, the
  41  * $HOME/.AFSSERVER file is checked, otherwise the "/.AFSSERVER" is
  42  * used.
  43  */
  44 afs_int32
  45 GetAfsServerAddr(char *syscall)
  46 {
  47     struct hostent *th;
  48
  49     if (hostAddrLookup) {
  50         /* Take advantage of caching and assume that the remote host
  51          * address won't change during a single program's invocation.
  52          */
  53         return hostAddr;
  54     }
  55     hostAddrLookup = 1;
  56
  57     if (!(afs_server = getenv("AFSSERVER"))) {
  58         char *home_dir;
  59         FILE *fp;
  60         int len = 0;
  61
  62         if (!(home_dir = getenv("HOME"))) {
  63             /* Our last chance is the "/.AFSSERVER" file */
  64             fp = fopen("/.AFSSERVER", "r");
  65             if (fp == 0) {
  66                 return 0;
  67             }
  68         } else {
  69             char *pathname;
  70
  71             len = asprintf(&pathname, "%s/%s", home_dir, ".AFSSERVER");
  72             if (len < 0 || pathname == NULL)
  73                 return 0;
  74             fp = fopen(pathname, "r");
  75             free(pathname);
  76
  77             if (fp == 0) {
  78                 /* Our last chance is the "/.AFSSERVER" file */
  79                 fp = fopen("/.AFSSERVER", "r");
  80                 if (fp == 0) {
  81                     return 0;
  82                 }
  83             }
  84         }
  85         if (fgets(server_name, 128, fp) != NULL)
  86             len = strlen(server_name);
  87         fclose(fp);
  88         if (len == 0) {
  89             return 0;
  90         }
  91         if (server_name[len - 1] == '\n') {
  92             server_name[len - 1] = 0;
  93         }
  94         afs_server = server_name;
  95     }
  96     th = gethostbyname(afs_server);
  97     if (!th) {
  98         printf("host %s not found; %s call aborted\n", afs_server, syscall);
  99         return 0;
 100     }
 101     memcpy(&hostAddr, th->h_addr, sizeof(hostAddr));
 102     return hostAddr;
 103 }
 104
 105
 106 /* Does the actual RX connection to the afs server */
 107 struct rx_connection *
 108 rx_connection(afs_int32 * errorcode, char *syscall)
 109 {
 110     struct rx_connection *conn;
 111     struct rx_securityClass *null_securityObject;
 112     afs_int32 host;
 113
 114     if (!(host = GetAfsServerAddr(syscall))) {
 115         *errorcode = -1;
 116         return (struct rx_connection *)0;
 117     }
 118     *errorcode = rx_Init(0);
 119     if (*errorcode) {
 120         printf("Rx initialize failed \n");
 121         return (struct rx_connection *)0;
 122     }
 123     null_securityObject = rxnull_NewClientSecurityObject();
 124     conn =
 125         rx_NewConnection(host, htons(AFSCONF_RMTSYSPORT), RMTSYS_SERVICEID,
 126                          null_securityObject, RX_SECIDX_NULL);
 127     if (!conn) {
 128         printf("Unable to make a new connection\n");
 129         *errorcode = -1;
 130         return (struct rx_connection *)0;
 131     }
 132     return conn;
 133 }
 134
 135
 136 /* WARNING: The calling program (i.e. klog) MUST be suid-root since we need to
 137  * do a setgroups(2) call with the new pag.... */
 138 #ifdef AFS_DUX40_ENV
 139 #pragma weak setpag = afs_setpag
 140 int
 141 afs_setpag(void)
 142 #else
 143 int
 144 setpag(void)
 145 #endif
 146 {
 147     struct rx_connection *conn;
 148     clientcred creds;
 149     afs_int32 errorcode, errornumber, newpag, ngroups, j;
 150     afs_uint32 groups[NGROUPS_MAX];
 151
 152     if (!(conn = rx_connection(&errorcode, "setpag"))) {
 153         /* Remote call can't be performed for some reason.
 154          * Try the local 'setpag' system call ... */
 155         errorcode = lsetpag();
 156         return errorcode;
 157     }
 158     ngroups = SetClientCreds(&creds, groups);
 159     errorcode = RMTSYS_SetPag(conn, &creds, &newpag, &errornumber);
 160     if (errornumber) {
 161         errno = errornumber;
 162         errorcode = -1;
 163         printf("Warning: Remote setpag to %s has failed (err=%d)...\n",
 164                afs_server, errno);
 165     }
 166     if (errorcode) {
 167         return errorcode;
 168     }
 169     if (afs_get_pag_from_groups(groups[0], groups[1]) == NOPAG) {
 170         /* we will have to shift grouplist to make room for pag */
 171         if (ngroups + 2 > NGROUPS_MAX) {
 172             /* this is what the real setpag returns */
 173             errno = E2BIG;
 174             return -1;
 175         }
 176         for (j = ngroups - 1; j >= 0; j--) {
 177             groups[j + 2] = groups[j];
 178         }
 179         ngroups += 2;
 180     }
 181     afs_get_groups_from_pag(newpag, &groups[0], &groups[1]);
 182     if (setgroups(ngroups, groups) == -1) {
 183         return -1;
 184     }
 185 #ifdef  AFS_HPUX_ENV
 186     errorcode = setuid(getuid());
 187 #else
 188     errorcode = setreuid(-1, getuid());
 189 #endif /* AFS_HPUX_ENV */
 190     return errorcode;
 191 }
 192
 193
 194 /* Remote pioctl(2) client routine */
 195 #ifdef AFS_DUX40_ENV
 196 #pragma weak pioctl = afs_pioctl
 197 int
 198 afs_pioctl(char *path, afs_int32 cmd, struct ViceIoctl *data,
 199            afs_int32 follow)
 200 #else
 201 int
 202 pioctl(char *path, afs_int32 cmd, struct ViceIoctl *data, afs_int32 follow)
 203 #endif
 204 {
 205     struct rx_connection *conn;
 206     clientcred creds;
 207     afs_int32 errorcode, errornumber, ins = data->in_size;
 208     afs_uint32 groups[NGROUPS_MAX];
 209     rmtbulk InData, OutData;
 210     char pathname[256], *pathp = pathname, *inbuffer;
 211     if (!(conn = rx_connection(&errorcode, "pioctl"))) {
 212         /* Remote call can't be performed for some reason.
 213          * Try the local 'pioctl' system call ... */
 214         errorcode = lpioctl(path, cmd, data, follow);
 215         return errorcode;
 216     }
 217     (void)SetClientCreds(&creds, groups);
 218 #ifdef  AFS_OSF_ENV
 219     if (!ins)
 220         ins = 1;
 221 #endif
 222     if (!(inbuffer = malloc(ins)))
 223         return (-1);            /* helpless here */
 224     if (data->in_size)
 225         memcpy(inbuffer, data->in, data->in_size);
 226     InData.rmtbulk_len = data->in_size;
 227     InData.rmtbulk_val = inbuffer;
 228     inparam_conversion(cmd, InData.rmtbulk_val, 0);
 229
 230     OutData.rmtbulk_len = MAXBUFFERLEN * sizeof(*OutData.rmtbulk_val);
 231     OutData.rmtbulk_val = malloc(OutData.rmtbulk_len);
 232     if (!OutData.rmtbulk_val) {
 233         free(inbuffer);
 234         return -1;
 235     }
 236
 237     /* We always need to pass absolute pathnames to the remote pioctl since we
 238      * lose the current directory value when doing an rpc call. Below we
 239      * prepend the current absolute path directory, if the name is relative */
 240     if (path) {
 241         if (*path != '/') {
 242             /* assuming relative path name */
 243             if (getcwd(pathname, 256) == NULL) {
 244                 free(inbuffer);
 245                 printf("getwd failed\n");
 246                 return -1;
 247             }
 248             strcpy(pathname + strlen(pathname), "/");
 249             strcat(pathname, path);
 250         } else {
 251             strcpy(pathname, path);
 252         }
 253     } else {
 254         /* Special meaning for a "NULL" pathname since xdr_string hates nil
 255          * pointers, at least on non-RTS; of course the proper solution would
 256          * be to change the interface declartion. */
 257         strcpy(pathname, NIL_PATHP);
 258     }
 259     errorcode =
 260         RMTSYS_Pioctl(conn, &creds, pathp, cmd, follow, &InData, &OutData,
 261                       &errornumber);
 262     if (errornumber) {
 263         errno = errornumber;
 264         errorcode = -1;         /* Necessary since errorcode is 0 on
 265                                  * standard remote pioctl errors */
 266         if (errno != EDOM && errno != EACCES)
 267             printf("Warning: Remote pioctl to %s has failed (err=%d)...\n",
 268                    afs_server, errno);
 269     }
 270     if (!errorcode) {
 271         /* Do the conversions back to the host order; store the results back
 272          * on the same buffer */
 273         if (data->out_size < OutData.rmtbulk_len) {
 274             errno = EINVAL;
 275             errorcode = -1;
 276         } else {
 277             memcpy(data->out, OutData.rmtbulk_val, data->out_size);
 278             outparam_conversion(cmd, data->out, 1);
 279         }
 280     }
 281     free(OutData.rmtbulk_val);
 282     free(inbuffer);
 283     return errorcode;
 284 }
 285
 286
 287 int
 288 afs_get_pag_from_groups(afs_uint32 g0, afs_uint32 g1)
 289 {
 290     afs_uint32 h, l, result;
 291
 292     g0 -= 0x3f00;
 293     g1 -= 0x3f00;
 294     if (g0 < 0xc000 && g1 < 0xc000) {
 295         l = ((g0 & 0x3fff) << 14) | (g1 & 0x3fff);
 296         h = (g0 >> 14);
 297         h = (g1 >> 14) + h + h + h;
 298         result = ((h << 28) | l);
 299         /* Additional testing */
 300         if (((result >> 24) & 0xff) == 'A')
 301             return result;
 302         else
 303             return NOPAG;
 304     }
 305     return NOPAG;
 306 }
 307
 308 void
 309 afs_get_groups_from_pag(afs_uint32 pag, afs_uint32 * g0p, afs_uint32 * g1p)
 310 {
 311     unsigned short g0, g1;
 312
 313     pag &= 0x7fffffff;
 314     g0 = 0x3fff & (pag >> 14);
 315     g1 = 0x3fff & pag;
 316     g0 |= ((pag >> 28) / 3) << 14;
 317     g1 |= ((pag >> 28) % 3) << 14;
 318     *g0p = g0 + 0x3f00;
 319     *g1p = g1 + 0x3f00;
 320 }
 321
 322
 323 static afs_int32
 324 SetClientCreds(struct clientcred *creds, afs_uint32 * groups)
 325 {
 326     afs_int32 ngroups;
 327
 328     creds->uid = getuid();
 329     groups[0] = groups[1] = 0;
 330     ngroups = getgroups(NGROUPS_MAX, groups);
 331     creds->group0 = groups[0];
 332     creds->group1 = groups[1];
 333     return ngroups;
 334 }