diff options
Diffstat (limited to 'tun.c')
| -rw-r--r-- | tun.c | 77 |
1 files changed, 54 insertions, 23 deletions
@@ -3643,17 +3643,21 @@ tun_standby (struct tuntap *tt) */ static void -write_dhcp_u8 (struct buffer *buf, const int type, const int data) +write_dhcp_u8 (struct buffer *buf, const int type, const int data, bool *error) { if (!buf_safe (buf, 3)) - msg (M_FATAL, "write_dhcp_u8: buffer overflow building DHCP options"); + { + *error = true; + msg (M_WARN, "write_dhcp_u8: buffer overflow building DHCP options"); + return; + } buf_write_u8 (buf, type); buf_write_u8 (buf, 1); buf_write_u8 (buf, data); } static void -write_dhcp_u32_array (struct buffer *buf, const int type, const uint32_t *data, const unsigned int len) +write_dhcp_u32_array (struct buffer *buf, const int type, const uint32_t *data, const unsigned int len, bool *error) { if (len > 0) { @@ -3661,9 +3665,17 @@ write_dhcp_u32_array (struct buffer *buf, const int type, const uint32_t *data, const int size = len * sizeof (uint32_t); if (!buf_safe (buf, 2 + size)) - msg (M_FATAL, "write_dhcp_u32_array: buffer overflow building DHCP options"); + { + *error = true; + msg (M_WARN, "write_dhcp_u32_array: buffer overflow building DHCP options"); + return; + } if (size < 1 || size > 255) - msg (M_FATAL, "write_dhcp_u32_array: size (%d) must be > 0 and <= 255", size); + { + *error = true; + msg (M_WARN, "write_dhcp_u32_array: size (%d) must be > 0 and <= 255", size); + return; + } buf_write_u8 (buf, type); buf_write_u8 (buf, size); for (i = 0; i < len; ++i) @@ -3672,46 +3684,61 @@ write_dhcp_u32_array (struct buffer *buf, const int type, const uint32_t *data, } static void -write_dhcp_str (struct buffer *buf, const int type, const char *str) +write_dhcp_str (struct buffer *buf, const int type, const char *str, bool *error) { const int len = strlen (str); if (!buf_safe (buf, 2 + len)) - msg (M_FATAL, "write_dhcp_str: buffer overflow building DHCP options"); + { + *error = true; + msg (M_WARN, "write_dhcp_str: buffer overflow building DHCP options"); + return; + } if (len < 1 || len > 255) - msg (M_FATAL, "write_dhcp_str: string '%s' must be > 0 bytes and <= 255 bytes", str); + { + *error = true; + msg (M_WARN, "write_dhcp_str: string '%s' must be > 0 bytes and <= 255 bytes", str); + return; + } buf_write_u8 (buf, type); buf_write_u8 (buf, len); buf_write (buf, str, len); } -static void +static bool build_dhcp_options_string (struct buffer *buf, const struct tuntap_options *o) { + bool error = false; if (o->domain) - write_dhcp_str (buf, 15, o->domain); + write_dhcp_str (buf, 15, o->domain, &error); if (o->netbios_scope) - write_dhcp_str (buf, 47, o->netbios_scope); + write_dhcp_str (buf, 47, o->netbios_scope, &error); if (o->netbios_node_type) - write_dhcp_u8 (buf, 46, o->netbios_node_type); + write_dhcp_u8 (buf, 46, o->netbios_node_type, &error); - write_dhcp_u32_array (buf, 6, (uint32_t*)o->dns, o->dns_len); - write_dhcp_u32_array (buf, 44, (uint32_t*)o->wins, o->wins_len); - write_dhcp_u32_array (buf, 42, (uint32_t*)o->ntp, o->ntp_len); - write_dhcp_u32_array (buf, 45, (uint32_t*)o->nbdd, o->nbdd_len); + write_dhcp_u32_array (buf, 6, (uint32_t*)o->dns, o->dns_len, &error); + write_dhcp_u32_array (buf, 44, (uint32_t*)o->wins, o->wins_len, &error); + write_dhcp_u32_array (buf, 42, (uint32_t*)o->ntp, o->ntp_len, &error); + write_dhcp_u32_array (buf, 45, (uint32_t*)o->nbdd, o->nbdd_len, &error); /* the MS DHCP server option 'Disable Netbios-over-TCP/IP is implemented as vendor option 001, value 002. A value of 001 means 'leave NBT alone' which is the default */ if (o->disable_nbt) { - buf_write_u8 (buf, 43); + if (!buf_safe (buf, 8)) + { + msg (M_WARN, "build_dhcp_options_string: buffer overflow building DHCP options"); + return false; + } + buf_write_u8 (buf, 43); buf_write_u8 (buf, 6); /* total length field */ buf_write_u8 (buf, 0x001); buf_write_u8 (buf, 4); /* length of the vendor specified field */ buf_write_u32 (buf, 0x002); } + return !error; } void @@ -4006,12 +4033,16 @@ open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6 if (tt->options.dhcp_options) { struct buffer buf = alloc_buf (256); - build_dhcp_options_string (&buf, &tt->options); - msg (D_DHCP_OPT, "DHCP option string: %s", format_hex (BPTR (&buf), BLEN (&buf), 0, &gc)); - if (!DeviceIoControl (tt->hand, TAP_IOCTL_CONFIG_DHCP_SET_OPT, - BPTR (&buf), BLEN (&buf), - BPTR (&buf), BLEN (&buf), &len, NULL)) - msg (M_FATAL, "ERROR: The TAP-Win32 driver rejected a TAP_IOCTL_CONFIG_DHCP_SET_OPT DeviceIoControl call"); + if (build_dhcp_options_string (&buf, &tt->options)) + { + msg (D_DHCP_OPT, "DHCP option string: %s", format_hex (BPTR (&buf), BLEN (&buf), 0, &gc)); + if (!DeviceIoControl (tt->hand, TAP_IOCTL_CONFIG_DHCP_SET_OPT, + BPTR (&buf), BLEN (&buf), + BPTR (&buf), BLEN (&buf), &len, NULL)) + msg (M_FATAL, "ERROR: The TAP-Win32 driver rejected a TAP_IOCTL_CONFIG_DHCP_SET_OPT DeviceIoControl call"); + } + else + msg (M_WARN, "DHCP option string not set due to error"); free_buf (&buf); } #endif |