diff options
Diffstat (limited to 'librpc/ndr')
| -rw-r--r-- | librpc/ndr/libndr.h | 1 | ||||
| -rw-r--r-- | librpc/ndr/ndr_dns.c | 210 | ||||
| -rw-r--r-- | librpc/ndr/ndr_dns.h | 3 |
3 files changed, 214 insertions, 0 deletions
diff --git a/librpc/ndr/libndr.h b/librpc/ndr/libndr.h index c110b76ae5..6bc96cada6 100644 --- a/librpc/ndr/libndr.h +++ b/librpc/ndr/libndr.h @@ -92,6 +92,7 @@ struct ndr_push { struct ndr_token_list *relative_list; struct ndr_token_list *relative_begin_list; struct ndr_token_list *nbt_string_list; + struct ndr_token_list *dns_string_list; struct ndr_token_list *full_ptr_list; /* this is used to ensure we generate unique reference IDs */ diff --git a/librpc/ndr/ndr_dns.c b/librpc/ndr/ndr_dns.c new file mode 100644 index 0000000000..18dde2bd1a --- /dev/null +++ b/librpc/ndr/ndr_dns.c @@ -0,0 +1,210 @@ +/* + Unix SMB/CIFS implementation. + + manipulate dns name structures + + Copyright (C) 2010 Kai Blin <kai@samba.org> + + Heavily based on nbtname.c which is: + + Copyright (C) Andrew Tridgell 2005 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +/* + see rfc1002 for the detailed format of compressed names +*/ + +#include "includes.h" +#include "librpc/gen_ndr/ndr_dns.h" +#include "librpc/gen_ndr/ndr_misc.h" +#include "system/locale.h" +#include "lib/util/util_net.h" + +/* don't allow an unlimited number of name components */ +#define MAX_COMPONENTS 10 + +/** + print a dns string +*/ +_PUBLIC_ void ndr_print_dns_string(struct ndr_print *ndr, const char *name, const char *s) +{ + ndr_print_string(ndr, name, s); +} + +/* + pull one component of a dns_string +*/ +static enum ndr_err_code ndr_pull_component(struct ndr_pull *ndr, + uint8_t **component, + uint32_t *offset, + uint32_t *max_offset) +{ + uint8_t len; + unsigned int loops = 0; + while (loops < 5) { + if (*offset >= ndr->data_size) { + return ndr_pull_error(ndr, NDR_ERR_STRING, + "BAD DNS NAME component"); + } + len = ndr->data[*offset]; + if (len == 0) { + *offset += 1; + *max_offset = MAX(*max_offset, *offset); + *component = NULL; + return NDR_ERR_SUCCESS; + } + if ((len & 0xC0) == 0xC0) { + /* its a label pointer */ + if (1 + *offset >= ndr->data_size) { + return ndr_pull_error(ndr, NDR_ERR_STRING, + "BAD DNS NAME component"); + } + *max_offset = MAX(*max_offset, *offset + 2); + *offset = ((len&0x3F)<<8) | ndr->data[1 + *offset]; + *max_offset = MAX(*max_offset, *offset); + loops++; + continue; + } + if ((len & 0xC0) != 0) { + /* its a reserved length field */ + return ndr_pull_error(ndr, NDR_ERR_STRING, + "BAD DNS NAME component"); + } + if (*offset + len + 2 > ndr->data_size) { + return ndr_pull_error(ndr, NDR_ERR_STRING, + "BAD DNS NAME component"); + } + *component = (uint8_t*)talloc_strndup(ndr, (const char *)&ndr->data[1 + *offset], len); + NDR_ERR_HAVE_NO_MEMORY(*component); + *offset += len + 1; + *max_offset = MAX(*max_offset, *offset); + return NDR_ERR_SUCCESS; + } + + /* too many pointers */ + return ndr_pull_error(ndr, NDR_ERR_STRING, "BAD DNS NAME component"); +} + +/** + pull a dns_string from the wire +*/ +_PUBLIC_ enum ndr_err_code ndr_pull_dns_string(struct ndr_pull *ndr, int ndr_flags, const char **s) +{ + uint32_t offset = ndr->offset; + uint32_t max_offset = offset; + unsigned num_components; + char *name; + + if (!(ndr_flags & NDR_SCALARS)) { + return NDR_ERR_SUCCESS; + } + + name = NULL; + + /* break up name into a list of components */ + for (num_components=0;num_components<MAX_COMPONENTS;num_components++) { + uint8_t *component = NULL; + NDR_CHECK(ndr_pull_component(ndr, &component, &offset, &max_offset)); + if (component == NULL) break; + if (name) { + name = talloc_asprintf_append_buffer(name, ".%s", component); + NDR_ERR_HAVE_NO_MEMORY(name); + } else { + name = (char *)component; + } + } + if (num_components == MAX_COMPONENTS) { + return ndr_pull_error(ndr, NDR_ERR_STRING, + "BAD DNS NAME too many components"); + } + if (num_components == 0) { + name = talloc_strdup(ndr, ""); + NDR_ERR_HAVE_NO_MEMORY(name); + } + + (*s) = name; + ndr->offset = max_offset; + + return NDR_ERR_SUCCESS; +} + +/** + push a dns string to the wire +*/ +_PUBLIC_ enum ndr_err_code ndr_push_dns_string(struct ndr_push *ndr, int ndr_flags, const char *s) +{ + if (!(ndr_flags & NDR_SCALARS)) { + return NDR_ERR_SUCCESS; + } + + while (s && *s) { + enum ndr_err_code ndr_err; + char *compname; + size_t complen; + uint32_t offset; + + /* see if we have pushed the remaing string allready, + * if so we use a label pointer to this string + */ + ndr_err = ndr_token_retrieve_cmp_fn(&ndr->dns_string_list, s, &offset, (comparison_fn_t)strcmp, false); + if (NDR_ERR_CODE_IS_SUCCESS(ndr_err)) { + uint8_t b[2]; + + if (offset > 0x3FFF) { + return ndr_push_error(ndr, NDR_ERR_STRING, + "offset for dns string label pointer %u[%08X] > 0x00003FFF", + offset, offset); + } + + b[0] = 0xC0 | (offset>>8); + b[1] = (offset & 0xFF); + + return ndr_push_bytes(ndr, b, 2); + } + + complen = strcspn(s, "."); + + /* we need to make sure the length fits into 6 bytes */ + if (complen > 0x3F) { + return ndr_push_error(ndr, NDR_ERR_STRING, + "component length %u[%08X] > 0x0000003F", + (unsigned)complen, (unsigned)complen); + } + + compname = talloc_asprintf(ndr, "%c%*.*s", + (unsigned char)complen, + (unsigned char)complen, + (unsigned char)complen, s); + NDR_ERR_HAVE_NO_MEMORY(compname); + + /* remember the current componemt + the rest of the string + * so it can be reused later + */ + NDR_CHECK(ndr_token_store(ndr, &ndr->dns_string_list, s, ndr->offset)); + + /* push just this component into the blob */ + NDR_CHECK(ndr_push_bytes(ndr, (const uint8_t *)compname, complen+1)); + talloc_free(compname); + + s += complen; + if (*s == '.') s++; + } + + /* if we reach the end of the string and have pushed the last component + * without using a label pointer, we need to terminate the string + */ + return ndr_push_bytes(ndr, (const uint8_t *)"", 1); +} diff --git a/librpc/ndr/ndr_dns.h b/librpc/ndr/ndr_dns.h new file mode 100644 index 0000000000..d0b6ab36f3 --- /dev/null +++ b/librpc/ndr/ndr_dns.h @@ -0,0 +1,3 @@ +_PUBLIC_ void ndr_print_dns_string(struct ndr_print *ndr, const char *name, const char *s); +_PUBLIC_ enum ndr_err_code ndr_pull_dns_string(struct ndr_pull *ndr, int ndr_flags, const char **s); +_PUBLIC_ enum ndr_err_code ndr_push_dns_string(struct ndr_push *ndr, int ndr_flags, const char *s); 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