1<!-- Creator : groff version 1.22.2 --> 2<!-- CreationDate: Thu Feb 2 22:36:46 2017 --> 3<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 4"http://www.w3.org/TR/html4/loose.dtd"> 5<html> 6<head> 7<meta name="generator" content="groff -Thtml, see www.gnu.org"> 8<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> 9<meta name="Content-Style" content="text/css"> 10<style type="text/css"> 11 p { margin-top: 0; margin-bottom: 0; vertical-align: top } 12 pre { margin-top: 0; margin-bottom: 0; vertical-align: top } 13 table { margin-top: 0; margin-bottom: 0; vertical-align: top } 14 h1 { text-align: center } 15</style> 16<title>mtcp_getsockopt</title> 17 18</head> 19<body> 20 21<h1 align="center">mtcp_getsockopt</h1> 22 23<a href="#NAME">NAME</a><br> 24<a href="#SYNOPSIS">SYNOPSIS</a><br> 25<a href="#DESCRIPTION">DESCRIPTION</a><br> 26<a href="#RETURN VALUE">RETURN VALUE</a><br> 27<a href="#ERRORS">ERRORS</a><br> 28<a href="#AUTHORS">AUTHORS</a><br> 29<a href="#SEE ALSO">SEE ALSO</a><br> 30<a href="#COLOPHON">COLOPHON</a><br> 31 32<hr> 33 34 35<h2>NAME 36<a name="NAME"></a> 37</h2> 38 39 40 41<p style="margin-left:11%; margin-top: 1em">mtcp_getsockopt 42− get options on mTCP/mOS sockets</p> 43 44<h2>SYNOPSIS 45<a name="SYNOPSIS"></a> 46</h2> 47 48 49<p style="margin-left:11%; margin-top: 1em"><b>#include 50<mtcp_api.h></b></p> 51 52<p style="margin-left:11%; margin-top: 1em"><b>int 53mtcp_getsockopt(mctx_t</b> <i>mctx</i><b>, int</b> 54<i>sockid</i><b>, int</b> <i>level</i><b>, int</b> 55<i>optname</i><b>, const void *</b><i>optval</i><b>, 56socklen_t *</b><i>optlen</i><b>);</b></p> 57 58<h2>DESCRIPTION 59<a name="DESCRIPTION"></a> 60</h2> 61 62 63 64<p style="margin-left:11%; margin-top: 1em"><b>mtcp_getsockopt</b>() 65manipulate options for the socket referred to by the 66<i>sockid</i> descriptor. These options may exist at 67multiple protocol levels. When manipulating socket options, 68the level at which the options resides and the name of the 69option must be specified. A user can use <b>SOL_SOCKET</b> 70<i>level</i> to adjust these options for mTCP endpoint 71applications; while <b>SOL_MONSOCKET</b> <i>level</i> can be 72used to adjust options for monitoring sockets.</p> 73 74<p style="margin-left:11%; margin-top: 1em">For 75<b>mtcp_getsockopt()</b> <i>optval</i> identifies the buffer 76in which the value for the requested option is to be 77returned and the <i>optlen</i> argument is updated to 78indicate the actual size of the <i>optval</i> returned. It 79is the user’s responsibility to allocate memory for 80both <i>optval</i> and <i>optlen</i> arguments.</p> 81 82<p style="margin-left:11%; margin-top: 1em">At the moment, 83mOS only provides one <i>optname</i> named <b>SO_ERROR</b> 84that can only be used for <b>mtcp_getsockopt()</b> function 85for SOL_SOCKET socket <i>level</i> with the specified option 86name returns the most recently recorded socket error for the 87particular connection (specific to the <i>sockid</i> socket 88descriptor).</p> 89 90<p style="margin-left:11%; margin-top: 1em">SOL_MONSOCKET 91socket <i>level</i> can be used by <b>mtcp_getsockopt()</b> 92to retrieve a number of socket options.</p> 93 94<table width="100%" border="0" rules="none" frame="void" 95 cellspacing="0" cellpadding="0"> 96<tr valign="top" align="left"> 97<td width="11%"></td> 98<td width="29%"> 99 100 101<p style="margin-top: 1em">MOS_FRAGINFO_CLIBUF</p></td> 102<td width="9%"></td> 103<td width="51%"> 104 105 106<p style="margin-top: 1em">Gives back offsets to fragments 107(non-contiguous data segments) currently stored in 108client’s TCP ring buffer. The <i>optval</i> is an 109array of struct tcp_ring_fragment which is defined as:</p></td></tr> 110</table> 111 112<p style="margin-left:49%; margin-top: 1em">struct 113tcp_ring_fragment { <br> 114uint64_t offset; <br> 115uint32_t len; <br> 116}</p> 117 118<p style="margin-left:49%; margin-top: 1em">where offset 119flow data starting from client’s TCP SYN sequence 120number, and len is the length of the tcp_ring_fragment. The 121<i>optval</i> holds the size of the array (in terms of the 122number of elements).</p> 123 124<table width="100%" border="0" rules="none" frame="void" 125 cellspacing="0" cellpadding="0"> 126<tr valign="top" align="left"> 127<td width="11%"></td> 128<td width="29%"> 129 130 131<p style="margin-top: 1em">MOS_FRAGINFO_SVRBUF</p></td> 132<td width="9%"></td> 133<td width="51%"> 134 135 136<p style="margin-top: 1em">Gives back offsets to fragments 137(non-contiguous data segments) currently stored in 138server’s TCP ring buffer. The <i>optval</i> is the 139array of struct tcp_ring_fragment</p></td></tr> 140</table> 141 142<p style="margin-left:49%; margin-top: 1em">where offset 143flow data starting from server’s TCP SYN sequence 144number, and len is the length of the tcp_ring_fragment. The 145<i>optlen</i> holds the size of the array (in terms of the 146number of elements).</p> 147 148<table width="100%" border="0" rules="none" frame="void" 149 cellspacing="0" cellpadding="0"> 150<tr valign="top" align="left"> 151<td width="11%"></td> 152<td width="23%"> 153 154 155<p style="margin-top: 1em">MOS_INFO_CLIBUF</p></td> 156<td width="15%"></td> 157<td width="51%"> 158 159 160<p style="margin-top: 1em">Returns meta-data regarding the 161client’s TCP ring buffer. This information is returned 162in the form of <i>optval</i> which is passed as struct 163tcp_buf_info.</p> </td></tr> 164</table> 165 166<p style="margin-left:49%; margin-top: 1em">struct 167tcp_buf_info { <br> 168/* The initial TCP sequence number <br> 169of TCP ring buffer. */ <br> 170uint32_t tcpbi_init_seq;</p> 171 172<p style="margin-left:49%; margin-top: 1em">/* TCP sequence 173number of the ’last <br> 174byte of payload that has already <br> 175been read by the end application’ <br> 176(applies in the case of embedded <br> 177monitor setup) */ <br> 178uint32_t tcpbi_last_byte_read;</p> 179 180<p style="margin-left:49%; margin-top: 1em">/* TCP sequence 181number of the ’last <br> 182byte of the payload that is <br> 183currently buffered and needs to <br> 184be read by the end application’ <br> 185(applies in the case of embedded <br> 186monitor setup). In case of standalone <br> 187monitors, tcpbi_last_byte_read = <br> 188tcpbi_next_byte_expected */ <br> 189uint32_t tcpbi_next_byte_expected;</p> 190 191<p style="margin-left:49%; margin-top: 1em">/* TCP sequence 192number of the ’last <br> 193byte of the payload that is <br> 194currently stored’ in the TCP <br> 195ring buffer. This value may be <br> 196greater than tcpbi_next_byte_expected <br> 197if packets arrive out of order. */ <br> 198uint32_t tcpbi_last_byte_received; <br> 199}</p> 200 201<p style="margin-left:49%; margin-top: 1em">The 202<i>optlen</i> value contains the sizeof(struct 203tcp_buf_info).</p> 204 205<table width="100%" border="0" rules="none" frame="void" 206 cellspacing="0" cellpadding="0"> 207<tr valign="top" align="left"> 208<td width="11%"></td> 209<td width="26%"> 210 211 212<p style="margin-top: 1em">MOS_INFO_SVRBUF</p></td> 213<td width="12%"></td> 214<td width="51%"> 215 216 217<p style="margin-top: 1em">Returns meta-data regarding the 218server’s TCP ring buffer. This information is returned 219in the form of <i>optval</i> which is passed as struct 220tcp_buf_info. The <i>optlen</i> value contains the 221sizeof(struct tcp_buf_info).</p></td></tr> 222<tr valign="top" align="left"> 223<td width="11%"></td> 224<td width="26%"> 225 226 227<p>MOS_TCP_STATE_CLI</p></td> 228<td width="12%"></td> 229<td width="51%"> 230 231 232<p>Returns the current emulated state of the client. The 233<i>optval</i> argument is a pointer to an int whereas the 234<i>optlen</i> argument contains the sizeof(int). The optval 235returns a value of type enum tcpstate which can carry any 236one of the following states.</p></td></tr> 237</table> 238 239<p style="margin-left:49%; margin-top: 1em">enum tcpstate { 240<br> 241TCP_CLOSED = 0, <br> 242TCP_LISTEN, <br> 243TCP_SYN_SENT, <br> 244TCP_SYN_RCVD, <br> 245TCP_ESTABLISHED, <br> 246TCP_FIN_WAIT_1, <br> 247TCP_FINE_WAIT_2, <br> 248TCP_CLOSE_WAIT, <br> 249TCP_CLOSING, <br> 250TCP_LAST_ACK, <br> 251TCP_TIME_WAIT <br> 252}</p> 253 254<table width="100%" border="0" rules="none" frame="void" 255 cellspacing="0" cellpadding="0"> 256<tr valign="top" align="left"> 257<td width="11%"></td> 258<td width="26%"> 259 260 261<p style="margin-top: 1em">MOS_TCP_STATE_SVR</p></td> 262<td width="12%"></td> 263<td width="51%"> 264 265 266<p style="margin-top: 1em">Returns the current emulated 267state of the server. The <i>optval</i> argument is a pointer 268to an int whereas the <i>optlen</i> argument contains the 269sizeof(int). The optval returns a value of type enum 270tcpstate.</p> </td></tr> 271</table> 272 273<p style="margin-left:11%; margin-top: 1em">Both the 274functions take an additional argument named <i>mctx</i> that 275represent the per-core mTCP context in an application (see 276<b>mtcp_create_context()</b> for details).</p> 277 278<h2>RETURN VALUE 279<a name="RETURN VALUE"></a> 280</h2> 281 282 283<p style="margin-left:11%; margin-top: 1em">Returns 0 on 284success; -1 on failure. In case of failure, <i>errno</i> is 285set appropriately.</p> 286 287<h2>ERRORS 288<a name="ERRORS"></a> 289</h2> 290 291 292<table width="100%" border="0" rules="none" frame="void" 293 cellspacing="0" cellpadding="0"> 294<tr valign="top" align="left"> 295<td width="11%"></td> 296<td width="12%"> 297 298 299<p style="margin-top: 1em"><b>EACCES</b></p></td> 300<td width="3%"></td> 301<td width="74%"> 302 303 304<p style="margin-top: 1em"><i>mctx</i> is not valid.</p></td></tr> 305<tr valign="top" align="left"> 306<td width="11%"></td> 307<td width="12%"> 308 309 310<p><b>EBADF</b></p></td> 311<td width="3%"></td> 312<td width="74%"> 313 314 315<p><i>sockid</i> is not a valid socket descriptor.</p></td></tr> 316<tr valign="top" align="left"> 317<td width="11%"></td> 318<td width="12%"> 319 320 321<p><b>ENOTSOCK</b></p></td> 322<td width="3%"></td> 323<td width="74%"> 324 325 326<p>The socket referred to by <i>sockid</i> is not 327valid.</p> </td></tr> 328<tr valign="top" align="left"> 329<td width="11%"></td> 330<td width="12%"> 331 332 333<p><b>ENOSYS</b></p></td> 334<td width="3%"></td> 335<td width="74%"> 336 337 338<p>Either the <i>level</i> or the <i>optname</i> is not 339implemented.</p> </td></tr> 340<tr valign="top" align="left"> 341<td width="11%"></td> 342<td width="12%"> 343 344 345<p><b>EPERM</b></p></td> 346<td width="3%"></td> 347<td width="74%"> 348 349 350<p>Permission to access a socket option is denied.</p></td></tr> 351</table> 352 353<h2>AUTHORS 354<a name="AUTHORS"></a> 355</h2> 356 357 358<p style="margin-left:22%; margin-top: 1em">mOS development 359team <[email protected]></p> 360 361<h2>SEE ALSO 362<a name="SEE ALSO"></a> 363</h2> 364 365 366 367<p style="margin-left:11%; margin-top: 1em"><b>mtcp_socket</b>(), 368<b>mtcp_setsockopt</b>()</p> 369 370<h2>COLOPHON 371<a name="COLOPHON"></a> 372</h2> 373 374 375<p style="margin-left:11%; margin-top: 1em">This page is 376part of mOS release 0.3 <i>docs</i> section. A description 377of the project, and information about reporting bugs, can be 378found at http://mos.kaist.edu/.</p> 379<hr> 380</body> 381</html> 382