Socket Level Properties

Starting with the Oracle Solaris 11.2 release, you can use the SO_FLOW_SLA option to set the service-level properties for the socket. A socket application using the SO_FLOW_SLA socket option causes the system to create a system flow, which is an enforcement mechanism for the service-level properties. You can use flowadm(1M) to observe the system flows. These system flows have the prefix <id>.sys.sock.

The pfiles(1) prints the SO_FLOW_SLA socket option with other socket options.

The usage of SO_FLOW_SLA socket option is described in the following example.

#include <sys/types.h>
#include <sys/socket.h>

extern struct sockaddr *serv_addr;

int fd;
mac_flow_props_t mprop;
mac_flow_props_t mprop_result;

fd = socket(AF_INET, SOCK_STREAM, 0);

mprop.mfp_version = MAC_FLOW_PROP_VERSION1;
mprop.mfp_mask = MFP_MAXBW | MFP_PRIORITY;
mprop.mfp_priority = MFP_PRIO_HIGH;
mprop.mfp_maxbw = 100000000;           /* in bits per second */
setsockopt(fd, SOL_SOCKET, SO_FLOW_SLA, &mprop, sizeof (mprop));

connect(fd, serv_addr, sizeof(*serv_addr));

getsockopt(fd, SOL_SOCKET, SO_FLOW_SLA, &mprop_result, sizeof (mprop_result));

In the example, the TCP client socket is created along with the system flow. The flow is set to a high priority and the maximum bandwidth is set to 100Mbps.

The system flow is created for the socket by calling connect() or accept() functions after setsockopt(3SOCKET). If either accept() or connect() function is already called, setting SO_FLOW_SLA will create a flow. Properties of the flow are set according to the values specified in mac_flow_props_t structure. This structure is passed as a pointer to setsockopt(3SOCKET) as an optval argument. You can know the status of the flow creation by using getsockopt(3SOCKET). The status is stored in the mprop_result.mfp_status field. The mac_flow_props_t structure is defined as follows.

typedef struct mac_flow_props_s {
int		mfp_version;
uint32_t   mfp_mask;
int		mfp_priority;   /* flow priority */
uint64_t   mfp_maxbw;	  /* bandwidth limit in bps */
int		mfp_status;	 /* flow create status for getsockopt */
} mac_flow_props_t;

The following list describes the fields of the mac_flow_props_t structure.

mfp_version

Denotes the version of the mac_flow_props_t structure. Currently, mfp_version can only be set to 1.

#define MAC_FLOW_PROP_VERSION1

mfp_mask

Denotes the bit mask values. The following bit mask values are valid.

• MRP_MAXBW

• MRP_PRIORITY

mfp_priority

Denotes the priority of processing the packets that belong to the socket. The following priority values are valid.

• MFP_PRIO_NORMAL

• MFP_PRIO_HIGH

mfp_maxbw

Denotes the maximum bandwidth allotted to the socket in bits per second. Value of 0 means all the packets of socket must be dropped.

mfp_status

Denotes the status of the flow creation. You can obtain the status of flow creation by calling getsockopt(3SOCKET). getsockopt(3SOCKET) sets the mfp_status field. A value of 0 means a flow is successfully created. In case of an error, this field is set to one of the following error codes.

• EPERM: No Privilege.

• ENOTCONN: If the call is made before the application does a connect or bind.

• EOPNOTSUPP: Flow creation is not supported for this socket.

• EALREADY: Flow with identical attributes exists.

• EINPROGRESS: Flow is being created.