From 41a89aeebac146000de97b778800e755db29568f Mon Sep 17 00:00:00 2001 From: Thomas Haller Date: Thu, 4 Jan 2018 16:12:40 +0100 Subject: [PATCH] dhcp: cleanup handling of ipv4.dhcp-client-id and avoid assertion failure The internal client asserts that the length of the client ID is not more than MAX_CLIENT_ID_LEN. Avoid that assert by truncating the string. Also add new nm_dhcp_client_set_client_id_*() setters, that either set the ID based on a string (in our common dhclient specific format), or based on the binary data (as obtained from systemd client). Also, add checks and assertions that the client ID which is set via nm_dhcp_client_set_client_id() is always of length of at least 2 (as required by rfc2132, section-9.14). (cherry picked from commit 686afe531ab3774cd818feda8361de74101971f5) --- libnm-core/nm-setting-ip4-config.c | 2 +- src/dhcp/nm-dhcp-client.c | 67 ++++++++++++++++--- src/dhcp/nm-dhcp-client.h | 9 ++- src/dhcp/nm-dhcp-dhclient-utils.c | 8 ++- src/dhcp/nm-dhcp-systemd.c | 18 ++--- src/dhcp/nm-dhcp-utils.c | 9 ++- src/nm-types.h | 2 + .../src/libsystemd-network/sd-dhcp-client.c | 1 + 8 files changed, 88 insertions(+), 28 deletions(-) diff --git a/libnm-core/nm-setting-ip4-config.c b/libnm-core/nm-setting-ip4-config.c index 26e7f5056c..d9c0cbb142 100644 --- a/libnm-core/nm-setting-ip4-config.c +++ b/libnm-core/nm-setting-ip4-config.c @@ -191,7 +191,7 @@ verify (NMSetting *setting, NMConnection *connection, GError **error) return FALSE; } - if (priv->dhcp_client_id && !strlen (priv->dhcp_client_id)) { + if (priv->dhcp_client_id && !priv->dhcp_client_id[0]) { g_set_error_literal (error, NM_CONNECTION_ERROR, NM_CONNECTION_ERROR_INVALID_PROPERTY, diff --git a/src/dhcp/nm-dhcp-client.c b/src/dhcp/nm-dhcp-client.c index 20ea092f0d..1f19db1481 100644 --- a/src/dhcp/nm-dhcp-client.c +++ b/src/dhcp/nm-dhcp-client.c @@ -186,19 +186,69 @@ nm_dhcp_client_get_client_id (NMDhcpClient *self) return NM_DHCP_CLIENT_GET_PRIVATE (self)->client_id; } +static void +_set_client_id (NMDhcpClient *self, GBytes *client_id, gboolean take) +{ + NMDhcpClientPrivate *priv = NM_DHCP_CLIENT_GET_PRIVATE (self); + + nm_assert (!client_id || g_bytes_get_size (client_id) >= 2); + + if ( priv->client_id == client_id + || ( priv->client_id + && g_bytes_equal (priv->client_id, client_id))) { + if (take && client_id) + g_bytes_unref (client_id); + return; + } + + if (priv->client_id) + g_bytes_unref (priv->client_id); + priv->client_id = client_id; + if (!take && client_id) + g_bytes_ref (client_id); +} + void nm_dhcp_client_set_client_id (NMDhcpClient *self, GBytes *client_id) { - NMDhcpClientPrivate *priv; + g_return_if_fail (NM_IS_DHCP_CLIENT (self)); + g_return_if_fail (!client_id || g_bytes_get_size (client_id) >= 2); + + _set_client_id (self, client_id, FALSE); +} + +void +nm_dhcp_client_set_client_id_bin (NMDhcpClient *self, + guint8 type, + const guint8 *client_id, + gsize len) +{ + guint8 *buf; + GBytes *b; g_return_if_fail (NM_IS_DHCP_CLIENT (self)); + g_return_if_fail (client_id); + g_return_if_fail (len > 0); - priv = NM_DHCP_CLIENT_GET_PRIVATE (self); + buf = g_malloc (len + 1); + buf[0] = type; + memcpy (buf + 1, client_id, len); + b = g_bytes_new_take (buf, len + 1); + _set_client_id (self, b, TRUE); +} - if (priv->client_id && client_id && g_bytes_equal (priv->client_id, client_id)) - return; - g_clear_pointer (&priv->client_id, g_bytes_unref); - priv->client_id = client_id ? g_bytes_ref (client_id) : NULL; +void +nm_dhcp_client_set_client_id_str (NMDhcpClient *self, + const char *dhcp_client_id) +{ + g_return_if_fail (NM_IS_DHCP_CLIENT (self)); + g_return_if_fail (!dhcp_client_id || dhcp_client_id[0]); + + _set_client_id (self, + dhcp_client_id + ? nm_dhcp_utils_client_id_string_to_bytes (dhcp_client_id) + : NULL, + TRUE); } const char * @@ -448,7 +498,6 @@ nm_dhcp_client_start_ip4 (NMDhcpClient *self, const char *last_ip4_address) { NMDhcpClientPrivate *priv; - gs_unref_bytes GBytes *tmp = NULL; g_return_val_if_fail (NM_IS_DHCP_CLIENT (self), FALSE); @@ -462,9 +511,7 @@ nm_dhcp_client_start_ip4 (NMDhcpClient *self, else _LOGI ("activation: beginning transaction (timeout in %u seconds)", (guint) priv->timeout); - if (dhcp_client_id) - tmp = nm_dhcp_utils_client_id_string_to_bytes (dhcp_client_id); - nm_dhcp_client_set_client_id (self, tmp); + nm_dhcp_client_set_client_id_str (self, dhcp_client_id); g_clear_pointer (&priv->hostname, g_free); priv->hostname = g_strdup (hostname); diff --git a/src/dhcp/nm-dhcp-client.h b/src/dhcp/nm-dhcp-client.h index 02804002f3..2c63416825 100644 --- a/src/dhcp/nm-dhcp-client.h +++ b/src/dhcp/nm-dhcp-client.h @@ -173,7 +173,14 @@ gboolean nm_dhcp_client_handle_event (gpointer unused, const char *reason, NMDhcpClient *self); -void nm_dhcp_client_set_client_id (NMDhcpClient *self, GBytes *client_id); +void nm_dhcp_client_set_client_id (NMDhcpClient *self, + GBytes *client_id); +void nm_dhcp_client_set_client_id_bin (NMDhcpClient *self, + guint8 type, + const guint8 *client_id, + gsize len); +void nm_dhcp_client_set_client_id_str (NMDhcpClient *self, + const char *dhcp_client_id); /***************************************************************************** * Client data diff --git a/src/dhcp/nm-dhcp-dhclient-utils.c b/src/dhcp/nm-dhcp-dhclient-utils.c index e63e6a8696..4df90d76a0 100644 --- a/src/dhcp/nm-dhcp-dhclient-utils.c +++ b/src/dhcp/nm-dhcp-dhclient-utils.c @@ -178,7 +178,7 @@ read_client_id (const char *str) gs_free char *s = NULL; char *p; - g_assert (!strncmp (str, CLIENTID_TAG, NM_STRLEN (CLIENTID_TAG))); + nm_assert (!strncmp (str, CLIENTID_TAG, NM_STRLEN (CLIENTID_TAG))); str += NM_STRLEN (CLIENTID_TAG); while (g_ascii_isspace (*str)) @@ -198,6 +198,9 @@ read_client_id (const char *str) if (s[strlen (s) - 1] == ';') s[strlen (s) - 1] = '\0'; + if (!s[0]) + return NULL; + return nm_dhcp_utils_client_id_string_to_bytes (s); } @@ -329,8 +332,7 @@ nm_dhcp_dhclient_create_config (const char *interface, continue; /* Otherwise capture and return the existing client id */ - if (out_new_client_id) - *out_new_client_id = read_client_id (p); + NM_SET_OUT (out_new_client_id, read_client_id (p)); } /* Override config file hostname and use one from the connection */ diff --git a/src/dhcp/nm-dhcp-systemd.c b/src/dhcp/nm-dhcp-systemd.c index 9b1a44332c..f79b7cb1e4 100644 --- a/src/dhcp/nm-dhcp-systemd.c +++ b/src/dhcp/nm-dhcp-systemd.c @@ -489,19 +489,13 @@ _save_client_id (NMDhcpSystemd *self, const uint8_t *client_id, size_t len) { - gs_unref_bytes GBytes *b = NULL; - gs_free char *buf = NULL; - g_return_if_fail (self != NULL); g_return_if_fail (client_id != NULL); g_return_if_fail (len > 0); if (!nm_dhcp_client_get_client_id (NM_DHCP_CLIENT (self))) { - buf = g_malloc (len + 1); - buf[0] = type; - memcpy (buf + 1, client_id, len); - b = g_bytes_new (buf, len + 1); - nm_dhcp_client_set_client_id (NM_DHCP_CLIENT (self), b); + nm_dhcp_client_set_client_id_bin (NM_DHCP_CLIENT (self), + type, client_id, len); } } @@ -543,7 +537,7 @@ bound4_handle (NMDhcpSystemd *self) add_requests_to_options (options, dhcp4_requests); dhcp_lease_save (lease, priv->lease_file); - sd_dhcp_client_get_client_id(priv->client4, &type, &client_id, &client_id_len); + sd_dhcp_client_get_client_id (priv->client4, &type, &client_id, &client_id_len); if (client_id) _save_client_id (self, type, client_id, client_id_len); @@ -691,14 +685,14 @@ ip4_start (NMDhcpClient *client, const char *dhcp_anycast_addr, const char *last override_client_id = nm_dhcp_client_get_client_id (client); if (override_client_id) { client_id = g_bytes_get_data (override_client_id, &client_id_len); - g_assert (client_id && client_id_len); + nm_assert (client_id && client_id_len >= 2); sd_dhcp_client_set_client_id (priv->client4, client_id[0], client_id + 1, - client_id_len - 1); + NM_MIN (client_id_len - 1, _NM_SD_MAX_CLIENT_ID_LEN)); } else if (lease) { r = sd_dhcp_lease_get_client_id (lease, (const void **) &client_id, &client_id_len); - if (r == 0 && client_id_len) { + if (r == 0 && client_id_len >= 2) { sd_dhcp_client_set_client_id (priv->client4, client_id[0], client_id + 1, diff --git a/src/dhcp/nm-dhcp-utils.c b/src/dhcp/nm-dhcp-utils.c index 4b2d57b90f..50ca2abe2d 100644 --- a/src/dhcp/nm-dhcp-utils.c +++ b/src/dhcp/nm-dhcp-utils.c @@ -750,8 +750,15 @@ nm_dhcp_utils_client_id_string_to_bytes (const char *client_id) g_return_val_if_fail (client_id && client_id[0], NULL); /* Try as hex encoded */ - if (strchr (client_id, ':')) + if (strchr (client_id, ':')) { bytes = nm_utils_hexstr2bin (client_id); + + /* the result must be at least two bytes long, + * because @client_id contains a delimiter + * but nm_utils_hexstr2bin() does not allow + * leading nor trailing delimiters. */ + nm_assert (!bytes || g_bytes_get_size (bytes) >= 2); + } if (!bytes) { /* Fall back to string */ len = strlen (client_id); diff --git a/src/nm-types.h b/src/nm-types.h index cc657397ea..02163f87e6 100644 --- a/src/nm-types.h +++ b/src/nm-types.h @@ -25,6 +25,8 @@ #error "nm-utils-private.h" must not be used outside of libnm-core/. Do you want "nm-core-internal.h"? #endif +#define _NM_SD_MAX_CLIENT_ID_LEN (sizeof (guint32) + 128) + /* core */ typedef struct _NMExportedObject NMExportedObject; typedef struct _NMActiveConnection NMActiveConnection; diff --git a/src/systemd/src/libsystemd-network/sd-dhcp-client.c b/src/systemd/src/libsystemd-network/sd-dhcp-client.c index fc6ad422d0..5eab005029 100644 --- a/src/systemd/src/libsystemd-network/sd-dhcp-client.c +++ b/src/systemd/src/libsystemd-network/sd-dhcp-client.c @@ -311,6 +311,7 @@ int sd_dhcp_client_set_client_id( assert_return(client, -EINVAL); assert_return(data, -EINVAL); assert_return(data_len > 0 && data_len <= MAX_CLIENT_ID_LEN, -EINVAL); + G_STATIC_ASSERT_EXPR (_NM_SD_MAX_CLIENT_ID_LEN == MAX_CLIENT_ID_LEN); switch (type) {