fdo-mirrors/NetworkManager
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/NetworkManager/NetworkManager.git synced 2026-01-26 13:10:34 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions

ndisc: fix encoding DNS Search List Option in RA

Browse source 
The format is different than what was implemented.

Read [1] or see systemd's implementation ([2]).

[1] https://tools.ietf.org/html/rfc8106#section-5.2
[2] 65ab27211c/src/libsystemd-network/sd-radv.c (L791)

Fixes: 6387856602 ('ndisc/lndp: add ability to announce the managed IPv6 configuration')
(cherry picked from commit 872f265859)
This commit is contained in:
Thomas Haller 2021-01-12 19:17:09 +01:00
parent 5dfbbb8ffe
commit 08492516e7
No known key found for this signature in database
GPG key ID: 29C2366E4DFC5728
1 changed files with 77 additions and 33 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

110
src/ndisc/nm-lndp-ndisc.c
View file

@ -13,6 +13,8 @@
#include <stdarg.h>
#include <ndp.h>
#include "nm-glib-aux/nm-str-buf.h"
#include "systemd/nm-sd-utils-shared.h"
#include "nm-ndisc-private.h"
#include "NetworkManagerUtils.h"
#include "platform/nm-platform.h"
@ -372,13 +374,14 @@ G_STATIC_ASSERT(sizeof(NMLndpDnsslOption) == 8u);
static gboolean
send_ra(NMNDisc *ndisc, GError **error)
{
NMLndpNDiscPrivate * priv = NM_LNDP_NDISC_GET_PRIVATE(ndisc);
NMNDiscDataInternal *rdata = ndisc->rdata;
gint32 now = nm_utils_get_monotonic_timestamp_sec();
int errsv;
struct in6_addr * addr;
struct ndp_msg * msg;
guint i;
NMLndpNDiscPrivate * priv = NM_LNDP_NDISC_GET_PRIVATE(ndisc);
NMNDiscDataInternal * rdata = ndisc->rdata;
gint32 now = nm_utils_get_monotonic_timestamp_sec();
int errsv;
struct in6_addr * addr;
struct ndp_msg * msg;
guint i;
nm_auto_str_buf NMStrBuf sbuf = NM_STR_BUF_INIT(0, FALSE);
errsv = ndp_msg_new(&msg, NDP_MSG_RA);
if (errsv) {
@ -458,39 +461,80 @@ send_ra(NMNDisc *ndisc, GError **error)
}
dns_servers_done:
if (rdata->dns_domains->len) {
if (rdata->dns_domains->len > 0u) {
NMLndpDnsslOption *option;
NMNDiscDNSDomain * dns_server;
int len = sizeof(*option);
uint8_t * search_list;
gsize padding;
gsize len;
nm_str_buf_reset(&sbuf, NULL);
for (i = 0; i < rdata->dns_domains->len; i++) {
dns_server = &g_array_index(rdata->dns_domains, NMNDiscDNSDomain, i);
len += strlen(dns_server->domain) + 2;
}
len = (len + 8) & ~0x7;
const NMNDiscDNSDomain *dns_domain =
&g_array_index(rdata->dns_domains, NMNDiscDNSDomain, i);
const char *domain = dns_domain->domain;
gsize domain_l;
gsize n_reserved;
int r;
option = _ndp_msg_add_option(msg, len);
if (option) {
option->header.nd_opt_type = NM_ND_OPT_DNSSL;
option->header.nd_opt_len = len / 8;
option->lifetime = htonl(900);
search_list = option->search_list;
for (i = 0; i < rdata->dns_domains->len; i++) {
NMNDiscDNSDomain *dns_domain =
&g_array_index(rdata->dns_domains, NMNDiscDNSDomain, i);
uint8_t domain_len = strlen(dns_domain->domain);
*search_list++ = domain_len;
memcpy(search_list, dns_domain->domain, domain_len);
search_list += domain_len;
*search_list++ = '\0';
if (nm_str_is_empty(domain)) {
nm_assert_not_reached();
continue;
}
} else {
_LOGW("The RA is too big, had to omit DNS search list.");
domain_l = strlen(domain);
nm_str_buf_maybe_expand(&sbuf, domain_l + 2u, FALSE);
n_reserved = sbuf.allocated - sbuf.len;
r = nm_sd_dns_name_to_wire_format(
domain,
(guint8 *) (&nm_str_buf_get_str_unsafe(&sbuf)[sbuf.len]),
n_reserved,
FALSE);
if (r < 0 || ((gsize) r) > n_reserved) {
nm_assert(r != -ENOBUFS);
nm_assert(r < 0);
/* we don't expect errors here, unless the domain name is invalid.
* That should have been caught (and rejected) by upper layers, but
* at this point it seems dangerous to assert (as it's hard to review
* that all callers got it correct). So instead silently ignore the error. */
continue;
}
nm_str_buf_set_size(&sbuf, sbuf.len + ((gsize) r), TRUE, FALSE);
}
if (sbuf.len == 0) {
/* no valid domains? */
goto dns_domains_done;
}
len = sizeof(*option) + sbuf.len;
padding = len % 8u;
if (padding != 0u) {
padding = 8u - padding;
len += padding;
}
nm_assert(len % 8u == 0u);
nm_assert(len > 0u);
nm_assert(len / 8u >= 2u);
if (len / 8u >= 256u || !(option = _ndp_msg_add_option(msg, len))) {
_LOGW("The RA is too big, had to omit DNS search list.");
goto dns_domains_done;
}
nm_str_buf_append_c_len(&sbuf, '\0', padding);
option->header.nd_opt_type = NM_ND_OPT_DNSSL;
option->header.nd_opt_len = len / 8u;
option->reserved = 0;
option->lifetime = htonl(900);
memcpy(option->search_list, nm_str_buf_get_str_unsafe(&sbuf), sbuf.len);
}
dns_domains_done:
errsv = ndp_msg_send(priv->ndp, msg);