diff options
| -rw-r--r-- | cifsacl.h | 4 | ||||
| -rw-r--r-- | setcifsacl.c | 253 | ||||
| -rw-r--r-- | setcifsacl.rst.in | 27 |
3 files changed, 235 insertions, 49 deletions
@@ -26,7 +26,9 @@ #define _CIFSACL_H #define BUFSIZE 1024 -#define ATTRNAME "system.cifs_acl" +#define ATTRNAME "system.cifs_acl" +#define ATTRNAME_ACL ATTRNAME +#define ATTRNAME_NTSD "system.cifs_ntsd" #define MAX_NUM_AUTHS 6 diff --git a/setcifsacl.c b/setcifsacl.c index 9a301e2..6e5a633 100644 --- a/setcifsacl.c +++ b/setcifsacl.c @@ -44,7 +44,9 @@ enum setcifsacl_actions { ActDelete, ActModify, ActAdd, - ActSet + ActSetAcl, + ActSetOwner, + ActSetGroup }; static void *plugin_handle; @@ -140,6 +142,90 @@ copy_sec_desc(const struct cifs_ntsd *pntsd, struct cifs_ntsd *pnntsd, return bufsize; } +/* + * This function (and the one above) does not need to set the SACL-related + * fields, and this works fine because on the SMB protocol level, setting owner + * info, DACL, and SACL requires one to use separate flags that control which + * part of the descriptor is begin looked at on the server side + */ +static ssize_t +copy_sec_desc_with_sid(const struct cifs_ntsd *pntsd, struct cifs_ntsd *pnntsd, + struct cifs_sid *sid, int maction) +{ + int size, daclsize; + int osidoffset, gsidoffset, dacloffset; + int nosidoffset, ngsidoffset, ndacloffset, nsidssize; + ssize_t bufsize; + struct cifs_sid *owner_sid_ptr, *group_sid_ptr; + struct cifs_sid *nowner_sid_ptr, *ngroup_sid_ptr; + struct cifs_ctrl_acl *dacl_ptr, *ndacl_ptr; + + /* copy security descriptor control portion */ + osidoffset = le32toh(pntsd->osidoffset); + gsidoffset = le32toh(pntsd->gsidoffset); + dacloffset = le32toh(pntsd->dacloffset); + /* + * the size of the owner or group sid might be different from the old + * one, so the group sid offest might change, and if the owner is + * positioned before the DACL, the dacl offset might change as well; + * note however, that the owner sid offset does not change + */ + nosidoffset = osidoffset; + size = sizeof(struct cifs_ntsd); + pnntsd->revision = pntsd->revision; + pnntsd->type = pntsd->type; + pnntsd->osidoffset = pntsd->osidoffset; + bufsize = size; + + /* set the pointers for source sids */ + if (maction == ActSetOwner) { + owner_sid_ptr = sid; + group_sid_ptr = (struct cifs_sid *)((char *)pntsd + gsidoffset); + } + if (maction == ActSetGroup) { + owner_sid_ptr = (struct cifs_sid *)((char *)pntsd + osidoffset); + group_sid_ptr = sid; + } + + dacl_ptr = (struct cifs_ctrl_acl *)((char *)pntsd + dacloffset); + daclsize = le16toh(dacl_ptr->size) + sizeof(struct cifs_ctrl_acl); + + /* copy owner sid */ + nowner_sid_ptr = (struct cifs_sid *)((char *)pnntsd + nosidoffset); + size = copy_cifs_sid(nowner_sid_ptr, owner_sid_ptr); + bufsize += size; + nsidssize = size; + + /* copy group sid */ + ngsidoffset = nosidoffset + size; + ngroup_sid_ptr = (struct cifs_sid *)((char *)pnntsd + ngsidoffset); + pnntsd->gsidoffset = htole32(ngsidoffset); + size = copy_cifs_sid(ngroup_sid_ptr, group_sid_ptr); + bufsize += size; + nsidssize += size; + + /* position the dacl control info as in the fetched descriptor */ + if (dacloffset <= osidoffset) + ndacloffset = dacloffset; + else + ndacloffset = nosidoffset + nsidssize; + ndacl_ptr = (struct cifs_ctrl_acl *)((char *)pnntsd + ndacloffset); + pnntsd->dacloffset = htole32(ndacloffset); + + /* the DACL control fields do not change */ + ndacl_ptr->revision = dacl_ptr->revision; + ndacl_ptr->size = dacl_ptr->size; + ndacl_ptr->num_aces = dacl_ptr->num_aces; + + /* + * add DACL size (control portion and the array of aces) to the + * buffer size + */ + bufsize += daclsize; + + return bufsize; +} + static int copy_ace(struct cifs_ace *dace, struct cifs_ace *sace) { @@ -788,7 +874,7 @@ setacl_action(struct cifs_ntsd *pntsd, struct cifs_ntsd **npntsd, rc = ace_add(pntsd, npntsd, bufsize, facesptr, numfaces, cacesptr, numcaces); break; - case ActSet: + case ActSetAcl: rc = ace_set(pntsd, npntsd, bufsize, cacesptr, numcaces); break; default: @@ -803,9 +889,10 @@ static void setcifsacl_usage(const char *prog) { fprintf(stderr, - "%s: Alter CIFS/NTFS ACL in a security descriptor of a file object\n", + "%s: Alter CIFS/NTFS ACL or owner/group in a security descriptor of a file object\n", + prog); + fprintf(stderr, "Usage: %s option [<list_of_ACEs>|<SID>] <file_name>\n", prog); - fprintf(stderr, "Usage: %s option <list_of_ACEs> <file_name>\n", prog); fprintf(stderr, "Valid options:\n"); fprintf(stderr, "\t-v Version of the program\n"); fprintf(stderr, "\n\t-a Add ACE(s), separated by a comma, to an ACL\n"); @@ -825,21 +912,32 @@ setcifsacl_usage(const char *prog) "\n\t-S Replace existing ACL with ACE(s), separated by a comma\n"); fprintf(stderr, "\tsetcifsacl -S \"ACL:Administrator:ALLOWED/0x0/D\" <file_name>\n"); + fprintf(stderr, + "\n\t-o Set owner using specified SID (name or raw format)\n"); + fprintf(stderr, + "\tsetcifsacl -o \"Administrator\" <file_name>\n"); + fprintf(stderr, + "\n\t-g Set group using specified SID (name or raw format)\n"); + fprintf(stderr, + "\tsetcifsacl -g \"Administrators\" <file_name>\n"); fprintf(stderr, "\nRefer to setcifsacl(1) manpage for details\n"); } int main(const int argc, char *const argv[]) { - int i, rc, c, numcaces, numfaces; + int i, rc, c, numcaces = 0, numfaces = 0; enum setcifsacl_actions maction = ActUnknown; ssize_t attrlen, bufsize = BUFSIZE; - char *ace_list, *filename, *attrval, **arrptr = NULL; + char *ace_list = NULL, *filename = NULL, *attrval = NULL, + **arrptr = NULL, *sid_str = NULL; struct cifs_ctrl_acl *daclptr = NULL; struct cifs_ace **cacesptr = NULL, **facesptr = NULL; struct cifs_ntsd *ntsdptr = NULL; + struct cifs_sid sid; + char *attrname = ATTRNAME_ACL; - c = getopt(argc, argv, "hvD:M:a:S:"); + c = getopt(argc, argv, "hvD:M:a:S:o:g:"); switch (c) { case 'D': maction = ActDelete; @@ -854,9 +952,19 @@ main(const int argc, char *const argv[]) ace_list = optarg; break; case 'S': - maction = ActSet; + maction = ActSetAcl; ace_list = optarg; break; + case 'o': + maction = ActSetOwner; + sid_str = optarg; + attrname = ATTRNAME_NTSD; + break; + case 'g': + maction = ActSetGroup; + sid_str = optarg; + attrname = ATTRNAME_NTSD; + break; case 'h': setcifsacl_usage(basename(argv[0])); return 0; @@ -875,11 +983,16 @@ main(const int argc, char *const argv[]) } filename = argv[3]; - if (!ace_list) { + if (!ace_list && maction != ActSetOwner && maction != ActSetGroup) { printf("%s: No valid ACEs specified\n", __func__); return -1; } + if (!sid_str && (maction == ActSetOwner || maction == ActSetGroup)) { + printf("%s: No valid SIDs specified\n", __func__); + return -1; + } + if (init_plugin(&plugin_handle)) { fprintf(stderr, "WARNING: unable to initialize idmapping " "plugin. Only \"raw\" SID strings will be " @@ -889,16 +1002,24 @@ main(const int argc, char *const argv[]) plugin_loaded = true; } - numcaces = get_numcaces(ace_list); - - arrptr = parse_cmdline_aces(ace_list, numcaces); - if (!arrptr) - goto setcifsacl_numcaces_ret; + if (maction == ActSetOwner || maction == ActSetGroup) { + /* parse the sid */ + if (setcifsacl_str_to_sid(sid_str, &sid)) { + printf("%s: failed to parce \'%s\' as SID\n", __func__, + sid_str); + goto setcifsacl_numcaces_ret; + } + } else { + numcaces = get_numcaces(ace_list); - cacesptr = build_cmdline_aces(arrptr, numcaces); - if (!cacesptr) - goto setcifsacl_cmdlineparse_ret; + arrptr = parse_cmdline_aces(ace_list, numcaces); + if (!arrptr) + goto setcifsacl_numcaces_ret; + cacesptr = build_cmdline_aces(arrptr, numcaces); + if (!cacesptr) + goto setcifsacl_cmdlineparse_ret; + } cifsacl: if (bufsize >= XATTR_SIZE_MAX) { printf("%s: Buffer size %zd exceeds max size of %d\n", @@ -912,7 +1033,7 @@ cifsacl: goto setcifsacl_cmdlineverify_ret; } - attrlen = getxattr(filename, ATTRNAME, attrval, bufsize); + attrlen = getxattr(filename, attrname, attrval, bufsize); if (attrlen == -1) { if (errno == ERANGE) { free(attrval); @@ -924,26 +1045,64 @@ cifsacl: } } - numfaces = get_numfaces((struct cifs_ntsd *)attrval, attrlen, &daclptr); - if (!numfaces && maction != ActAdd) { /* if we are not adding aces */ - printf("%s: Empty DACL\n", __func__); - goto setcifsacl_facenum_ret; - } + if (maction == ActSetOwner || maction == ActSetGroup) { + struct cifs_ntsd *pfntsd = (struct cifs_ntsd *)attrval; + int dacloffset = le32toh(pfntsd->dacloffset); + struct cifs_ctrl_acl *daclinfo = + (struct cifs_ctrl_acl *)(attrval + dacloffset); + int numaces = le16toh(daclinfo->num_aces); + int acessize = le32toh(daclinfo->size); + size_t faceoffset, naceoffset; + char *faceptr, *naceptr; - facesptr = build_fetched_aces((char *)daclptr, numfaces); - if (!facesptr) - goto setcifsacl_facenum_ret; + /* + * this allocates large enough buffer for max sid size and the + * dacl info from the fetched security descriptor + */ + rc = alloc_sec_desc(pfntsd, &ntsdptr, numaces, &faceoffset); + if (rc) + goto setcifsacl_numcaces_ret; - bufsize = 0; - rc = setacl_action((struct cifs_ntsd *)attrval, &ntsdptr, &bufsize, - facesptr, numfaces, cacesptr, numcaces, maction); - if (rc) - goto setcifsacl_action_ret; + /* + * copy the control structures from the fetched descriptor, the + * sid specified by the user, and adjust the offsets/move dacl + * control structure if needed + */ + bufsize = copy_sec_desc_with_sid(pfntsd, ntsdptr, &sid, + maction); + + /* copy aces verbatim as they have not changed */ + faceptr = attrval + faceoffset; + naceoffset = le32toh(ntsdptr->dacloffset) + + sizeof(struct cifs_ctrl_acl); + naceptr = (char *)ntsdptr + naceoffset; + memcpy(naceptr, faceptr, acessize); + } else { + bufsize = 0; + + numfaces = get_numfaces((struct cifs_ntsd *)attrval, attrlen, + &daclptr); + if (!numfaces && maction != ActAdd) { + /* if we are not adding aces */ + printf("%s: Empty DACL\n", __func__); + goto setcifsacl_facenum_ret; + } + + facesptr = build_fetched_aces((char *)daclptr, numfaces); + if (!facesptr) + goto setcifsacl_facenum_ret; - attrlen = setxattr(filename, ATTRNAME, ntsdptr, bufsize, 0); + rc = setacl_action((struct cifs_ntsd *)attrval, &ntsdptr, + &bufsize, facesptr, numfaces, cacesptr, + numcaces, maction); + if (rc) + goto setcifsacl_action_ret; + } + + attrlen = setxattr(filename, attrname, ntsdptr, bufsize, 0); if (attrlen == -1) { printf("%s: setxattr error: %s\n", __func__, strerror(errno)); - goto setcifsacl_facenum_ret; + goto setcifsacl_action_ret; } if (plugin_loaded) @@ -951,25 +1110,33 @@ cifsacl: return 0; setcifsacl_action_ret: - free(ntsdptr); + if (ntsdptr) + free(ntsdptr); setcifsacl_facenum_ret: - for (i = 0; i < numfaces; ++i) - free(facesptr[i]); - free(facesptr); + if (facesptr) { + for (i = 0; i < numfaces; ++i) + free(facesptr[i]); + free(facesptr); + } setcifsacl_getx_ret: - free(attrval); + if (attrval) + free(attrval); setcifsacl_cmdlineverify_ret: - for (i = 0; i < numcaces; ++i) - free(cacesptr[i]); - free(cacesptr); + if (cacesptr) { + for (i = 0; i < numcaces; ++i) + free(cacesptr[i]); + free(cacesptr); + } setcifsacl_cmdlineparse_ret: - free(arrptr); + if (arrptr) + free(arrptr); setcifsacl_numcaces_ret: - exit_plugin(plugin_handle); + if (plugin_loaded) + exit_plugin(plugin_handle); return -1; } diff --git a/setcifsacl.rst.in b/setcifsacl.rst.in index de9c758..985af7c 100644 --- a/setcifsacl.rst.in +++ b/setcifsacl.rst.in @@ -2,16 +2,16 @@ setcifsacl ========== ------------------------------------------------------------------------------------------------- -Userspace helper to alter an ACL in a security descriptor for Common Internet File System (CIFS) ------------------------------------------------------------------------------------------------- +------------------------------------------------------------------------------------------------------------------- +Userspace helper to alter an ACL or owner/group SID in a security descriptor for Common Internet File System (CIFS) +------------------------------------------------------------------------------------------------------------------- :Manual section: 1 ******** SYNOPSIS ******** - setcifsacl [-v|-a|-D|-M|-S] "{one or more ACEs}" {file system object} + setcifsacl [-v|-a|-D|-M|-S|-o|-g] "{one or more ACEs or a SID}" {file system object} *********** DESCRIPTION @@ -20,7 +20,7 @@ DESCRIPTION This tool is part of the cifs-utils suite. ``setcifsacl`` is a userspace helper program for the Linux CIFS client -file system. It is intended to alter an ACL of a security descriptor +file system. It is intended to alter an ACL or set owner/group SID of a security descriptor for a file system object. Whether a security descriptor to be set is applied or not is determined by the CIFS/SMB server. @@ -55,6 +55,13 @@ OPTIONS Set an ACL of security descriptor with the list of ACEs Existing ACL is replaced entirely with the specified ACEs. +-o + Set owner SID to one specified as a command line argument. + +-g + Set group SID to one specified as a command line argument. + + The owner/group SID can be specified as a name or a raw SID value. Every ACE entry starts with "ACL:" One or more ACEs are specified within double quotes. Multiple ACEs are separated by a comma. @@ -93,6 +100,16 @@ Set an ACL setcifsacl -S "ACL:CIFSTESTDOM\Administrator:0x0/0x0/FULL,ACL:CIFSTESTDOM\user2:0x0/0x0/FULL" <file_name> +Set owner SID +============= + + setcifsacl -o "S-1-5-21-3338130290-3403600371-1423429424-2102" <file_name> + +Set group SID +============= + + setcifsacl -g "Administrators@BUILTIN" <file_name> + ***** NOTES ***** |