ipnet and DLPI

Device nodes created in /dev/ipnet are DLPI style-1 devices. All M_PROTO and M_PCPROTO-type messages are interpreted as DLPI primitives. Because the device is read-only and packets can only be observed by opening them, the following subset of DLPI primitives is supported:

DL_INFO_REQ
DL_BIND_REQ
DL_UNBIND_REQ
DL_PROMISCON_REQ
DL_PROMISCOFF_REQ
DLIOCRAW

The values returned by the driver in the DL_INFO_ACK primitive in response to the DL_INFO_REQ are:

The /dev/ipnet/* and /dev/lo0 devices only accept DL_BIND_REQ requests for SAPs 4 (IPv4 packets), 6 (IPv6 packets), or 0 (all IP packets). DL_BIND_REQ requests for other SAP values result in a DL_ERROR_ACK of DL_BADSAP.

ipnet primitives

For /dev/ipnet/* devices, the DL_PROMISCON_REQ and DL_PROMISCOFF_REQ primitives with the DL_PROMISC_PHYS flag set in the dl_level field enables/disables the reception of all packets. When disabled, only packets with addresses matching any of the configured addresses on the IP interface are received. When used with the DL_PROMISC_MULTI flag set, reception of all multicast group addresses can be enabled/disabled. DL_PROMISC_PHYS and DL_PROMISC_MULTI have no effect for /dev/lo0. When the DL_PROMISC_SAP flag is set, reception of all IPv4/IPv6 can be enabled/disabled.

The DLIOCRAW ioctl is supported but has no effect on the data returned from the device.

The DL_IOC_IPNET_INFO ioctl enables/disables the inclusion of a dl_ipnetinfo_t structure that is prepended to the IP header when receiving packet data. When enabled, a non-zero integer is returned reflecting the current DL_IOC_IPNET_INFO version. The dl_ipnetinfo_t data structure is defined in <sys/dlpi.h> and includes the following fields:

uint8_t  dli_version;  /* DL_IPNETINFO_* version */
uint8_t  dli_ipver;    /* packet IP header version */
uint16_t dli_len;      /* length of dl_ipnetinfo_t */
uint64_t dli_srczone;  /* packet source zone ID (if any) */
uint64_t dli_dstzone;  /* packet dest zone ID (if any) */

The current dli_version is 1. To robustly support future dl_ipnetinfo_t versions, consumers should check that dli_version is a value they recognize, and must use the dli_len field to advance past the dl_ipnetinfo_t header.