This patch implements section 5.3.6. of RFC6458, that is, support for 'SCTP Next Receive Information Structure' (SCTP_NXTINFO) which is placed into ancillary data cmsghdr structure for each recvmsg() call, if this information is already available when delivering the current message. This option can be enabled/disabled via setsockopt(2) on SOL_SCTP level by setting an int value with 1/0 for SCTP_RECVNXTINFO in user space applications as per RFC6458, section 8.1.30. The sctp_nxtinfo structure is defined as per RFC as below ... struct sctp_nxtinfo { uint16_t nxt_sid; uint16_t nxt_flags; uint32_t nxt_ppid; uint32_t nxt_length; sctp_assoc_t nxt_assoc_id; }; ... and provided under cmsg_level IPPROTO_SCTP, cmsg_type SCTP_NXTINFO, while cmsg_data[] contains struct sctp_nxtinfo. Joint work with Daniel Borkmann.
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| @@ -96,6 +96,7 @@ typedef __s32 sctp_assoc_t; · 95 unmodified lines | ||
| 96 | 96 | #define SCTP_AUTO_ASCONF 30 |
| 97 | 97 | #define SCTP_PEER_ADDR_THLDS 31 |
| 98 | 98 | #define SCTP_RECVRCVINFO 32 |
| 99 | +#define SCTP_RECVNXTINFO 33 | |
| 99 | 100 | |
| 100 | 101 | /* Internal Socket Options. Some of the sctp library functions are |
| 101 | 102 | * implemented using these socket options. |
| @@ -111,6 +112,13 @@ typedef __s32 sctp_assoc_t; · 9 unmodified lines | ||
| 111 | 112 | #define SCTP_SOCKOPT_CONNECTX3 111 /* CONNECTX requests (updated) */ |
| 112 | 113 | #define SCTP_GET_ASSOC_STATS 112 /* Read only */ |
| 113 | 114 | |
| 115 | +/* These are bit fields for msghdr->msg_flags. See section 5.1. */ | |
| 116 | +/* On user space Linux, these live in <bits/socket.h> as an enum. */ | |
| 117 | +enum sctp_msg_flags { | |
| 118 | + MSG_NOTIFICATION = 0x8000, | |
| 119 | +#define MSG_NOTIFICATION MSG_NOTIFICATION | |
| 120 | +}; | |
| 121 | + | |
| 114 | 122 | /* 5.3.1 SCTP Initiation Structure (SCTP_INIT) |
| 115 | 123 | * |
| 116 | 124 | * This cmsghdr structure provides information for initializing new |
| @@ -187,6 +195,25 @@ struct sctp_rcvinfo { · 70 unmodified lines | ||
| 187 | 195 | sctp_assoc_t rcv_assoc_id; |
| 188 | 196 | }; |
| 189 | 197 | |
| 198 | +/* 5.3.6 SCTP Next Receive Information Structure (SCTP_NXTINFO) | |
| 199 | + * | |
| 200 | + * This cmsghdr structure describes SCTP receive information | |
| 201 | + * of the next message that will be delivered through recvmsg() | |
| 202 | + * if this information is already available when delivering | |
| 203 | + * the current message. | |
| 204 | + * | |
| 205 | + * cmsg_level cmsg_type cmsg_data[] | |
| 206 | + * ------------ ------------ ------------------- | |
| 207 | + * IPPROTO_SCTP SCTP_NXTINFO struct sctp_nxtinfo | |
| 208 | + */ | |
| 209 | +struct sctp_nxtinfo { | |
| 210 | + __u16 nxt_sid; | |
| 211 | + __u16 nxt_flags; | |
| 212 | + __u32 nxt_ppid; | |
| 213 | + __u32 nxt_length; | |
| 214 | + sctp_assoc_t nxt_assoc_id; | |
| 215 | +}; | |
| 216 | + | |
| 190 | 217 | /* |
| 191 | 218 | * sinfo_flags: 16 bits (unsigned integer) |
| 192 | 219 | * |
| @@ -194,11 +221,12 @@ struct sctp_rcvinfo { · 1 unmodified line | ||
| 194 | 221 | * a bitwise OR of these values. |
| 195 | 222 | */ |
| 196 | 223 | enum sctp_sinfo_flags { |
| 197 | − SCTP_UNORDERED = 1, /* Send/receive message unordered. */ | |
| 198 | − SCTP_ADDR_OVER = 2, /* Override the primary destination. */ | |
| 199 | − SCTP_ABORT=4, /* Send an ABORT message to the peer. */ | |
| 200 | − SCTP_SACK_IMMEDIATELY = 8, /* SACK should be sent without delay */ | |
| 201 | − SCTP_EOF=MSG_FIN, /* Initiate graceful shutdown process. */ | |
| 224 | + SCTP_UNORDERED = (1 << 0), /* Send/receive message unordered. */ | |
| 225 | + SCTP_ADDR_OVER = (1 << 1), /* Override the primary destination. */ | |
| 226 | + SCTP_ABORT = (1 << 2), /* Send an ABORT message to the peer. */ | |
| 227 | + SCTP_SACK_IMMEDIATELY = (1 << 3), /* SACK should be sent without delay. */ | |
| 228 | + SCTP_NOTIFICATION = MSG_NOTIFICATION, /* Next message is not user msg but notification. */ | |
| 229 | + SCTP_EOF = MSG_FIN, /* Initiate graceful shutdown process. */ | |
| 202 | 230 | }; |
| 203 | 231 | |
| 204 | 232 | typedef union { |
| @@ -217,6 +245,8 @@ typedef enum sctp_cmsg_type { · 12 unmodified lines | ||
| 217 | 245 | #define SCTP_SNDINFO SCTP_SNDINFO |
| 218 | 246 | SCTP_RCVINFO, /* 5.3.5 SCTP Receive Information Structure */ |
| 219 | 247 | #define SCTP_RCVINFO SCTP_RCVINFO |
| 248 | + SCTP_NXTINFO, /* 5.3.6 SCTP Next Receive Information Structure */ | |
| 249 | +#define SCTP_NXTINFO SCTP_NXTINFO | |
| 220 | 250 | } sctp_cmsg_t; |
| 221 | 251 | |
| 222 | 252 | /* |
| @@ -844,13 +874,6 @@ struct sctp_assoc_stats { · 621 unmodified lines | ||
| 844 | 874 | __u64 sas_ictrlchunks; /* Control chunks received */ |
| 845 | 875 | }; |
| 846 | 876 | |
| 847 | −/* These are bit fields for msghdr->msg_flags. See section 5.1. */ | |
| 848 | −/* On user space Linux, these live in <bits/socket.h> as an enum. */ | |
| 849 | −enum sctp_msg_flags { | |
| 850 | − MSG_NOTIFICATION = 0x8000, | |
| 851 | −#define MSG_NOTIFICATION MSG_NOTIFICATION | |
| 852 | −}; | |
| 853 | − | |
| 854 | 877 | /* |
| 855 | 878 | * 8.1 sctp_bindx() |
| 856 | 879 | * |