1*baacf047SPaolo Bonzini /* 2*baacf047SPaolo Bonzini * Helpers for getting linearized buffers from iov / filling buffers into iovs 3*baacf047SPaolo Bonzini * 4*baacf047SPaolo Bonzini * Copyright IBM, Corp. 2007, 2008 5*baacf047SPaolo Bonzini * Copyright (C) 2010 Red Hat, Inc. 6*baacf047SPaolo Bonzini * 7*baacf047SPaolo Bonzini * Author(s): 8*baacf047SPaolo Bonzini * Anthony Liguori <aliguori@us.ibm.com> 9*baacf047SPaolo Bonzini * Amit Shah <amit.shah@redhat.com> 10*baacf047SPaolo Bonzini * Michael Tokarev <mjt@tls.msk.ru> 11*baacf047SPaolo Bonzini * 12*baacf047SPaolo Bonzini * This work is licensed under the terms of the GNU GPL, version 2. See 13*baacf047SPaolo Bonzini * the COPYING file in the top-level directory. 14*baacf047SPaolo Bonzini * 15*baacf047SPaolo Bonzini * Contributions after 2012-01-13 are licensed under the terms of the 16*baacf047SPaolo Bonzini * GNU GPL, version 2 or (at your option) any later version. 17*baacf047SPaolo Bonzini */ 18*baacf047SPaolo Bonzini 19*baacf047SPaolo Bonzini #include "qemu/iov.h" 20*baacf047SPaolo Bonzini 21*baacf047SPaolo Bonzini #ifdef _WIN32 22*baacf047SPaolo Bonzini # include <windows.h> 23*baacf047SPaolo Bonzini # include <winsock2.h> 24*baacf047SPaolo Bonzini #else 25*baacf047SPaolo Bonzini # include <sys/types.h> 26*baacf047SPaolo Bonzini # include <sys/socket.h> 27*baacf047SPaolo Bonzini #endif 28*baacf047SPaolo Bonzini 29*baacf047SPaolo Bonzini size_t iov_from_buf(const struct iovec *iov, unsigned int iov_cnt, 30*baacf047SPaolo Bonzini size_t offset, const void *buf, size_t bytes) 31*baacf047SPaolo Bonzini { 32*baacf047SPaolo Bonzini size_t done; 33*baacf047SPaolo Bonzini unsigned int i; 34*baacf047SPaolo Bonzini for (i = 0, done = 0; (offset || done < bytes) && i < iov_cnt; i++) { 35*baacf047SPaolo Bonzini if (offset < iov[i].iov_len) { 36*baacf047SPaolo Bonzini size_t len = MIN(iov[i].iov_len - offset, bytes - done); 37*baacf047SPaolo Bonzini memcpy(iov[i].iov_base + offset, buf + done, len); 38*baacf047SPaolo Bonzini done += len; 39*baacf047SPaolo Bonzini offset = 0; 40*baacf047SPaolo Bonzini } else { 41*baacf047SPaolo Bonzini offset -= iov[i].iov_len; 42*baacf047SPaolo Bonzini } 43*baacf047SPaolo Bonzini } 44*baacf047SPaolo Bonzini assert(offset == 0); 45*baacf047SPaolo Bonzini return done; 46*baacf047SPaolo Bonzini } 47*baacf047SPaolo Bonzini 48*baacf047SPaolo Bonzini size_t iov_to_buf(const struct iovec *iov, const unsigned int iov_cnt, 49*baacf047SPaolo Bonzini size_t offset, void *buf, size_t bytes) 50*baacf047SPaolo Bonzini { 51*baacf047SPaolo Bonzini size_t done; 52*baacf047SPaolo Bonzini unsigned int i; 53*baacf047SPaolo Bonzini for (i = 0, done = 0; (offset || done < bytes) && i < iov_cnt; i++) { 54*baacf047SPaolo Bonzini if (offset < iov[i].iov_len) { 55*baacf047SPaolo Bonzini size_t len = MIN(iov[i].iov_len - offset, bytes - done); 56*baacf047SPaolo Bonzini memcpy(buf + done, iov[i].iov_base + offset, len); 57*baacf047SPaolo Bonzini done += len; 58*baacf047SPaolo Bonzini offset = 0; 59*baacf047SPaolo Bonzini } else { 60*baacf047SPaolo Bonzini offset -= iov[i].iov_len; 61*baacf047SPaolo Bonzini } 62*baacf047SPaolo Bonzini } 63*baacf047SPaolo Bonzini assert(offset == 0); 64*baacf047SPaolo Bonzini return done; 65*baacf047SPaolo Bonzini } 66*baacf047SPaolo Bonzini 67*baacf047SPaolo Bonzini size_t iov_memset(const struct iovec *iov, const unsigned int iov_cnt, 68*baacf047SPaolo Bonzini size_t offset, int fillc, size_t bytes) 69*baacf047SPaolo Bonzini { 70*baacf047SPaolo Bonzini size_t done; 71*baacf047SPaolo Bonzini unsigned int i; 72*baacf047SPaolo Bonzini for (i = 0, done = 0; (offset || done < bytes) && i < iov_cnt; i++) { 73*baacf047SPaolo Bonzini if (offset < iov[i].iov_len) { 74*baacf047SPaolo Bonzini size_t len = MIN(iov[i].iov_len - offset, bytes - done); 75*baacf047SPaolo Bonzini memset(iov[i].iov_base + offset, fillc, len); 76*baacf047SPaolo Bonzini done += len; 77*baacf047SPaolo Bonzini offset = 0; 78*baacf047SPaolo Bonzini } else { 79*baacf047SPaolo Bonzini offset -= iov[i].iov_len; 80*baacf047SPaolo Bonzini } 81*baacf047SPaolo Bonzini } 82*baacf047SPaolo Bonzini assert(offset == 0); 83*baacf047SPaolo Bonzini return done; 84*baacf047SPaolo Bonzini } 85*baacf047SPaolo Bonzini 86*baacf047SPaolo Bonzini size_t iov_size(const struct iovec *iov, const unsigned int iov_cnt) 87*baacf047SPaolo Bonzini { 88*baacf047SPaolo Bonzini size_t len; 89*baacf047SPaolo Bonzini unsigned int i; 90*baacf047SPaolo Bonzini 91*baacf047SPaolo Bonzini len = 0; 92*baacf047SPaolo Bonzini for (i = 0; i < iov_cnt; i++) { 93*baacf047SPaolo Bonzini len += iov[i].iov_len; 94*baacf047SPaolo Bonzini } 95*baacf047SPaolo Bonzini return len; 96*baacf047SPaolo Bonzini } 97*baacf047SPaolo Bonzini 98*baacf047SPaolo Bonzini /* helper function for iov_send_recv() */ 99*baacf047SPaolo Bonzini static ssize_t 100*baacf047SPaolo Bonzini do_send_recv(int sockfd, struct iovec *iov, unsigned iov_cnt, bool do_send) 101*baacf047SPaolo Bonzini { 102*baacf047SPaolo Bonzini #if defined CONFIG_IOVEC && defined CONFIG_POSIX 103*baacf047SPaolo Bonzini ssize_t ret; 104*baacf047SPaolo Bonzini struct msghdr msg; 105*baacf047SPaolo Bonzini memset(&msg, 0, sizeof(msg)); 106*baacf047SPaolo Bonzini msg.msg_iov = iov; 107*baacf047SPaolo Bonzini msg.msg_iovlen = iov_cnt; 108*baacf047SPaolo Bonzini do { 109*baacf047SPaolo Bonzini ret = do_send 110*baacf047SPaolo Bonzini ? sendmsg(sockfd, &msg, 0) 111*baacf047SPaolo Bonzini : recvmsg(sockfd, &msg, 0); 112*baacf047SPaolo Bonzini } while (ret < 0 && errno == EINTR); 113*baacf047SPaolo Bonzini return ret; 114*baacf047SPaolo Bonzini #else 115*baacf047SPaolo Bonzini /* else send piece-by-piece */ 116*baacf047SPaolo Bonzini /*XXX Note: windows has WSASend() and WSARecv() */ 117*baacf047SPaolo Bonzini unsigned i = 0; 118*baacf047SPaolo Bonzini ssize_t ret = 0; 119*baacf047SPaolo Bonzini while (i < iov_cnt) { 120*baacf047SPaolo Bonzini ssize_t r = do_send 121*baacf047SPaolo Bonzini ? send(sockfd, iov[i].iov_base, iov[i].iov_len, 0) 122*baacf047SPaolo Bonzini : recv(sockfd, iov[i].iov_base, iov[i].iov_len, 0); 123*baacf047SPaolo Bonzini if (r > 0) { 124*baacf047SPaolo Bonzini ret += r; 125*baacf047SPaolo Bonzini } else if (!r) { 126*baacf047SPaolo Bonzini break; 127*baacf047SPaolo Bonzini } else if (errno == EINTR) { 128*baacf047SPaolo Bonzini continue; 129*baacf047SPaolo Bonzini } else { 130*baacf047SPaolo Bonzini /* else it is some "other" error, 131*baacf047SPaolo Bonzini * only return if there was no data processed. */ 132*baacf047SPaolo Bonzini if (ret == 0) { 133*baacf047SPaolo Bonzini ret = -1; 134*baacf047SPaolo Bonzini } 135*baacf047SPaolo Bonzini break; 136*baacf047SPaolo Bonzini } 137*baacf047SPaolo Bonzini i++; 138*baacf047SPaolo Bonzini } 139*baacf047SPaolo Bonzini return ret; 140*baacf047SPaolo Bonzini #endif 141*baacf047SPaolo Bonzini } 142*baacf047SPaolo Bonzini 143*baacf047SPaolo Bonzini ssize_t iov_send_recv(int sockfd, struct iovec *iov, unsigned iov_cnt, 144*baacf047SPaolo Bonzini size_t offset, size_t bytes, 145*baacf047SPaolo Bonzini bool do_send) 146*baacf047SPaolo Bonzini { 147*baacf047SPaolo Bonzini ssize_t ret; 148*baacf047SPaolo Bonzini unsigned si, ei; /* start and end indexes */ 149*baacf047SPaolo Bonzini if (bytes == 0) { 150*baacf047SPaolo Bonzini /* Catch the do-nothing case early, as otherwise we will pass an 151*baacf047SPaolo Bonzini * empty iovec to sendmsg/recvmsg(), and not all implementations 152*baacf047SPaolo Bonzini * accept this. 153*baacf047SPaolo Bonzini */ 154*baacf047SPaolo Bonzini return 0; 155*baacf047SPaolo Bonzini } 156*baacf047SPaolo Bonzini 157*baacf047SPaolo Bonzini /* Find the start position, skipping `offset' bytes: 158*baacf047SPaolo Bonzini * first, skip all full-sized vector elements, */ 159*baacf047SPaolo Bonzini for (si = 0; si < iov_cnt && offset >= iov[si].iov_len; ++si) { 160*baacf047SPaolo Bonzini offset -= iov[si].iov_len; 161*baacf047SPaolo Bonzini } 162*baacf047SPaolo Bonzini if (offset) { 163*baacf047SPaolo Bonzini assert(si < iov_cnt); 164*baacf047SPaolo Bonzini /* second, skip `offset' bytes from the (now) first element, 165*baacf047SPaolo Bonzini * undo it on exit */ 166*baacf047SPaolo Bonzini iov[si].iov_base += offset; 167*baacf047SPaolo Bonzini iov[si].iov_len -= offset; 168*baacf047SPaolo Bonzini } 169*baacf047SPaolo Bonzini /* Find the end position skipping `bytes' bytes: */ 170*baacf047SPaolo Bonzini /* first, skip all full-sized elements */ 171*baacf047SPaolo Bonzini for (ei = si; ei < iov_cnt && iov[ei].iov_len <= bytes; ++ei) { 172*baacf047SPaolo Bonzini bytes -= iov[ei].iov_len; 173*baacf047SPaolo Bonzini } 174*baacf047SPaolo Bonzini if (bytes) { 175*baacf047SPaolo Bonzini /* second, fixup the last element, and remember 176*baacf047SPaolo Bonzini * the length we've cut from the end of it in `bytes' */ 177*baacf047SPaolo Bonzini size_t tail; 178*baacf047SPaolo Bonzini assert(ei < iov_cnt); 179*baacf047SPaolo Bonzini assert(iov[ei].iov_len > bytes); 180*baacf047SPaolo Bonzini tail = iov[ei].iov_len - bytes; 181*baacf047SPaolo Bonzini iov[ei].iov_len = bytes; 182*baacf047SPaolo Bonzini bytes = tail; /* bytes is now equal to the tail size */ 183*baacf047SPaolo Bonzini ++ei; 184*baacf047SPaolo Bonzini } 185*baacf047SPaolo Bonzini 186*baacf047SPaolo Bonzini ret = do_send_recv(sockfd, iov + si, ei - si, do_send); 187*baacf047SPaolo Bonzini 188*baacf047SPaolo Bonzini /* Undo the changes above */ 189*baacf047SPaolo Bonzini if (offset) { 190*baacf047SPaolo Bonzini iov[si].iov_base -= offset; 191*baacf047SPaolo Bonzini iov[si].iov_len += offset; 192*baacf047SPaolo Bonzini } 193*baacf047SPaolo Bonzini if (bytes) { 194*baacf047SPaolo Bonzini iov[ei-1].iov_len += bytes; 195*baacf047SPaolo Bonzini } 196*baacf047SPaolo Bonzini 197*baacf047SPaolo Bonzini return ret; 198*baacf047SPaolo Bonzini } 199*baacf047SPaolo Bonzini 200*baacf047SPaolo Bonzini 201*baacf047SPaolo Bonzini void iov_hexdump(const struct iovec *iov, const unsigned int iov_cnt, 202*baacf047SPaolo Bonzini FILE *fp, const char *prefix, size_t limit) 203*baacf047SPaolo Bonzini { 204*baacf047SPaolo Bonzini unsigned int i, v, b; 205*baacf047SPaolo Bonzini uint8_t *c; 206*baacf047SPaolo Bonzini 207*baacf047SPaolo Bonzini c = iov[0].iov_base; 208*baacf047SPaolo Bonzini for (i = 0, v = 0, b = 0; b < limit; i++, b++) { 209*baacf047SPaolo Bonzini if (i == iov[v].iov_len) { 210*baacf047SPaolo Bonzini i = 0; v++; 211*baacf047SPaolo Bonzini if (v == iov_cnt) { 212*baacf047SPaolo Bonzini break; 213*baacf047SPaolo Bonzini } 214*baacf047SPaolo Bonzini c = iov[v].iov_base; 215*baacf047SPaolo Bonzini } 216*baacf047SPaolo Bonzini if ((b % 16) == 0) { 217*baacf047SPaolo Bonzini fprintf(fp, "%s: %04x:", prefix, b); 218*baacf047SPaolo Bonzini } 219*baacf047SPaolo Bonzini if ((b % 4) == 0) { 220*baacf047SPaolo Bonzini fprintf(fp, " "); 221*baacf047SPaolo Bonzini } 222*baacf047SPaolo Bonzini fprintf(fp, " %02x", c[i]); 223*baacf047SPaolo Bonzini if ((b % 16) == 15) { 224*baacf047SPaolo Bonzini fprintf(fp, "\n"); 225*baacf047SPaolo Bonzini } 226*baacf047SPaolo Bonzini } 227*baacf047SPaolo Bonzini if ((b % 16) != 0) { 228*baacf047SPaolo Bonzini fprintf(fp, "\n"); 229*baacf047SPaolo Bonzini } 230*baacf047SPaolo Bonzini } 231*baacf047SPaolo Bonzini 232*baacf047SPaolo Bonzini unsigned iov_copy(struct iovec *dst_iov, unsigned int dst_iov_cnt, 233*baacf047SPaolo Bonzini const struct iovec *iov, unsigned int iov_cnt, 234*baacf047SPaolo Bonzini size_t offset, size_t bytes) 235*baacf047SPaolo Bonzini { 236*baacf047SPaolo Bonzini size_t len; 237*baacf047SPaolo Bonzini unsigned int i, j; 238*baacf047SPaolo Bonzini for (i = 0, j = 0; i < iov_cnt && j < dst_iov_cnt && bytes; i++) { 239*baacf047SPaolo Bonzini if (offset >= iov[i].iov_len) { 240*baacf047SPaolo Bonzini offset -= iov[i].iov_len; 241*baacf047SPaolo Bonzini continue; 242*baacf047SPaolo Bonzini } 243*baacf047SPaolo Bonzini len = MIN(bytes, iov[i].iov_len - offset); 244*baacf047SPaolo Bonzini 245*baacf047SPaolo Bonzini dst_iov[j].iov_base = iov[i].iov_base + offset; 246*baacf047SPaolo Bonzini dst_iov[j].iov_len = len; 247*baacf047SPaolo Bonzini j++; 248*baacf047SPaolo Bonzini bytes -= len; 249*baacf047SPaolo Bonzini offset = 0; 250*baacf047SPaolo Bonzini } 251*baacf047SPaolo Bonzini assert(offset == 0); 252*baacf047SPaolo Bonzini return j; 253*baacf047SPaolo Bonzini } 254*baacf047SPaolo Bonzini 255*baacf047SPaolo Bonzini /* io vectors */ 256*baacf047SPaolo Bonzini 257*baacf047SPaolo Bonzini void qemu_iovec_init(QEMUIOVector *qiov, int alloc_hint) 258*baacf047SPaolo Bonzini { 259*baacf047SPaolo Bonzini qiov->iov = g_malloc(alloc_hint * sizeof(struct iovec)); 260*baacf047SPaolo Bonzini qiov->niov = 0; 261*baacf047SPaolo Bonzini qiov->nalloc = alloc_hint; 262*baacf047SPaolo Bonzini qiov->size = 0; 263*baacf047SPaolo Bonzini } 264*baacf047SPaolo Bonzini 265*baacf047SPaolo Bonzini void qemu_iovec_init_external(QEMUIOVector *qiov, struct iovec *iov, int niov) 266*baacf047SPaolo Bonzini { 267*baacf047SPaolo Bonzini int i; 268*baacf047SPaolo Bonzini 269*baacf047SPaolo Bonzini qiov->iov = iov; 270*baacf047SPaolo Bonzini qiov->niov = niov; 271*baacf047SPaolo Bonzini qiov->nalloc = -1; 272*baacf047SPaolo Bonzini qiov->size = 0; 273*baacf047SPaolo Bonzini for (i = 0; i < niov; i++) 274*baacf047SPaolo Bonzini qiov->size += iov[i].iov_len; 275*baacf047SPaolo Bonzini } 276*baacf047SPaolo Bonzini 277*baacf047SPaolo Bonzini void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len) 278*baacf047SPaolo Bonzini { 279*baacf047SPaolo Bonzini assert(qiov->nalloc != -1); 280*baacf047SPaolo Bonzini 281*baacf047SPaolo Bonzini if (qiov->niov == qiov->nalloc) { 282*baacf047SPaolo Bonzini qiov->nalloc = 2 * qiov->nalloc + 1; 283*baacf047SPaolo Bonzini qiov->iov = g_realloc(qiov->iov, qiov->nalloc * sizeof(struct iovec)); 284*baacf047SPaolo Bonzini } 285*baacf047SPaolo Bonzini qiov->iov[qiov->niov].iov_base = base; 286*baacf047SPaolo Bonzini qiov->iov[qiov->niov].iov_len = len; 287*baacf047SPaolo Bonzini qiov->size += len; 288*baacf047SPaolo Bonzini ++qiov->niov; 289*baacf047SPaolo Bonzini } 290*baacf047SPaolo Bonzini 291*baacf047SPaolo Bonzini /* 292*baacf047SPaolo Bonzini * Concatenates (partial) iovecs from src_iov to the end of dst. 293*baacf047SPaolo Bonzini * It starts copying after skipping `soffset' bytes at the 294*baacf047SPaolo Bonzini * beginning of src and adds individual vectors from src to 295*baacf047SPaolo Bonzini * dst copies up to `sbytes' bytes total, or up to the end 296*baacf047SPaolo Bonzini * of src_iov if it comes first. This way, it is okay to specify 297*baacf047SPaolo Bonzini * very large value for `sbytes' to indicate "up to the end 298*baacf047SPaolo Bonzini * of src". 299*baacf047SPaolo Bonzini * Only vector pointers are processed, not the actual data buffers. 300*baacf047SPaolo Bonzini */ 301*baacf047SPaolo Bonzini void qemu_iovec_concat_iov(QEMUIOVector *dst, 302*baacf047SPaolo Bonzini struct iovec *src_iov, unsigned int src_cnt, 303*baacf047SPaolo Bonzini size_t soffset, size_t sbytes) 304*baacf047SPaolo Bonzini { 305*baacf047SPaolo Bonzini int i; 306*baacf047SPaolo Bonzini size_t done; 307*baacf047SPaolo Bonzini assert(dst->nalloc != -1); 308*baacf047SPaolo Bonzini for (i = 0, done = 0; done < sbytes && i < src_cnt; i++) { 309*baacf047SPaolo Bonzini if (soffset < src_iov[i].iov_len) { 310*baacf047SPaolo Bonzini size_t len = MIN(src_iov[i].iov_len - soffset, sbytes - done); 311*baacf047SPaolo Bonzini qemu_iovec_add(dst, src_iov[i].iov_base + soffset, len); 312*baacf047SPaolo Bonzini done += len; 313*baacf047SPaolo Bonzini soffset = 0; 314*baacf047SPaolo Bonzini } else { 315*baacf047SPaolo Bonzini soffset -= src_iov[i].iov_len; 316*baacf047SPaolo Bonzini } 317*baacf047SPaolo Bonzini } 318*baacf047SPaolo Bonzini assert(soffset == 0); /* offset beyond end of src */ 319*baacf047SPaolo Bonzini } 320*baacf047SPaolo Bonzini 321*baacf047SPaolo Bonzini /* 322*baacf047SPaolo Bonzini * Concatenates (partial) iovecs from src to the end of dst. 323*baacf047SPaolo Bonzini * It starts copying after skipping `soffset' bytes at the 324*baacf047SPaolo Bonzini * beginning of src and adds individual vectors from src to 325*baacf047SPaolo Bonzini * dst copies up to `sbytes' bytes total, or up to the end 326*baacf047SPaolo Bonzini * of src if it comes first. This way, it is okay to specify 327*baacf047SPaolo Bonzini * very large value for `sbytes' to indicate "up to the end 328*baacf047SPaolo Bonzini * of src". 329*baacf047SPaolo Bonzini * Only vector pointers are processed, not the actual data buffers. 330*baacf047SPaolo Bonzini */ 331*baacf047SPaolo Bonzini void qemu_iovec_concat(QEMUIOVector *dst, 332*baacf047SPaolo Bonzini QEMUIOVector *src, size_t soffset, size_t sbytes) 333*baacf047SPaolo Bonzini { 334*baacf047SPaolo Bonzini qemu_iovec_concat_iov(dst, src->iov, src->niov, soffset, sbytes); 335*baacf047SPaolo Bonzini } 336*baacf047SPaolo Bonzini 337*baacf047SPaolo Bonzini void qemu_iovec_destroy(QEMUIOVector *qiov) 338*baacf047SPaolo Bonzini { 339*baacf047SPaolo Bonzini assert(qiov->nalloc != -1); 340*baacf047SPaolo Bonzini 341*baacf047SPaolo Bonzini qemu_iovec_reset(qiov); 342*baacf047SPaolo Bonzini g_free(qiov->iov); 343*baacf047SPaolo Bonzini qiov->nalloc = 0; 344*baacf047SPaolo Bonzini qiov->iov = NULL; 345*baacf047SPaolo Bonzini } 346*baacf047SPaolo Bonzini 347*baacf047SPaolo Bonzini void qemu_iovec_reset(QEMUIOVector *qiov) 348*baacf047SPaolo Bonzini { 349*baacf047SPaolo Bonzini assert(qiov->nalloc != -1); 350*baacf047SPaolo Bonzini 351*baacf047SPaolo Bonzini qiov->niov = 0; 352*baacf047SPaolo Bonzini qiov->size = 0; 353*baacf047SPaolo Bonzini } 354*baacf047SPaolo Bonzini 355*baacf047SPaolo Bonzini size_t qemu_iovec_to_buf(QEMUIOVector *qiov, size_t offset, 356*baacf047SPaolo Bonzini void *buf, size_t bytes) 357*baacf047SPaolo Bonzini { 358*baacf047SPaolo Bonzini return iov_to_buf(qiov->iov, qiov->niov, offset, buf, bytes); 359*baacf047SPaolo Bonzini } 360*baacf047SPaolo Bonzini 361*baacf047SPaolo Bonzini size_t qemu_iovec_from_buf(QEMUIOVector *qiov, size_t offset, 362*baacf047SPaolo Bonzini const void *buf, size_t bytes) 363*baacf047SPaolo Bonzini { 364*baacf047SPaolo Bonzini return iov_from_buf(qiov->iov, qiov->niov, offset, buf, bytes); 365*baacf047SPaolo Bonzini } 366*baacf047SPaolo Bonzini 367*baacf047SPaolo Bonzini size_t qemu_iovec_memset(QEMUIOVector *qiov, size_t offset, 368*baacf047SPaolo Bonzini int fillc, size_t bytes) 369*baacf047SPaolo Bonzini { 370*baacf047SPaolo Bonzini return iov_memset(qiov->iov, qiov->niov, offset, fillc, bytes); 371*baacf047SPaolo Bonzini } 372*baacf047SPaolo Bonzini 373*baacf047SPaolo Bonzini size_t iov_discard_front(struct iovec **iov, unsigned int *iov_cnt, 374*baacf047SPaolo Bonzini size_t bytes) 375*baacf047SPaolo Bonzini { 376*baacf047SPaolo Bonzini size_t total = 0; 377*baacf047SPaolo Bonzini struct iovec *cur; 378*baacf047SPaolo Bonzini 379*baacf047SPaolo Bonzini for (cur = *iov; *iov_cnt > 0; cur++) { 380*baacf047SPaolo Bonzini if (cur->iov_len > bytes) { 381*baacf047SPaolo Bonzini cur->iov_base += bytes; 382*baacf047SPaolo Bonzini cur->iov_len -= bytes; 383*baacf047SPaolo Bonzini total += bytes; 384*baacf047SPaolo Bonzini break; 385*baacf047SPaolo Bonzini } 386*baacf047SPaolo Bonzini 387*baacf047SPaolo Bonzini bytes -= cur->iov_len; 388*baacf047SPaolo Bonzini total += cur->iov_len; 389*baacf047SPaolo Bonzini *iov_cnt -= 1; 390*baacf047SPaolo Bonzini } 391*baacf047SPaolo Bonzini 392*baacf047SPaolo Bonzini *iov = cur; 393*baacf047SPaolo Bonzini return total; 394*baacf047SPaolo Bonzini } 395*baacf047SPaolo Bonzini 396*baacf047SPaolo Bonzini size_t iov_discard_back(struct iovec *iov, unsigned int *iov_cnt, 397*baacf047SPaolo Bonzini size_t bytes) 398*baacf047SPaolo Bonzini { 399*baacf047SPaolo Bonzini size_t total = 0; 400*baacf047SPaolo Bonzini struct iovec *cur; 401*baacf047SPaolo Bonzini 402*baacf047SPaolo Bonzini if (*iov_cnt == 0) { 403*baacf047SPaolo Bonzini return 0; 404*baacf047SPaolo Bonzini } 405*baacf047SPaolo Bonzini 406*baacf047SPaolo Bonzini cur = iov + (*iov_cnt - 1); 407*baacf047SPaolo Bonzini 408*baacf047SPaolo Bonzini while (*iov_cnt > 0) { 409*baacf047SPaolo Bonzini if (cur->iov_len > bytes) { 410*baacf047SPaolo Bonzini cur->iov_len -= bytes; 411*baacf047SPaolo Bonzini total += bytes; 412*baacf047SPaolo Bonzini break; 413*baacf047SPaolo Bonzini } 414*baacf047SPaolo Bonzini 415*baacf047SPaolo Bonzini bytes -= cur->iov_len; 416*baacf047SPaolo Bonzini total += cur->iov_len; 417*baacf047SPaolo Bonzini cur--; 418*baacf047SPaolo Bonzini *iov_cnt -= 1; 419*baacf047SPaolo Bonzini } 420*baacf047SPaolo Bonzini 421*baacf047SPaolo Bonzini return total; 422*baacf047SPaolo Bonzini } 423