diff options
Diffstat (limited to 'iov.c')
| -rw-r--r-- | iov.c | 192 |
1 files changed, 141 insertions, 51 deletions
@@ -7,6 +7,7 @@ * Author(s): * Anthony Liguori <aliguori@us.ibm.com> * Amit Shah <amit.shah@redhat.com> + * Michael Tokarev <mjt@tls.msk.ru> * * This work is licensed under the terms of the GNU GPL, version 2. See * the COPYING file in the top-level directory. @@ -17,75 +18,69 @@ #include "iov.h" +#ifdef _WIN32 +# include <windows.h> +# include <winsock2.h> +#else +# include <sys/types.h> +# include <sys/socket.h> +#endif + size_t iov_from_buf(struct iovec *iov, unsigned int iov_cnt, - const void *buf, size_t iov_off, size_t size) + size_t offset, const void *buf, size_t bytes) { - size_t iovec_off, buf_off; + size_t done; unsigned int i; - - iovec_off = 0; - buf_off = 0; - for (i = 0; i < iov_cnt && size; i++) { - if (iov_off < (iovec_off + iov[i].iov_len)) { - size_t len = MIN((iovec_off + iov[i].iov_len) - iov_off, size); - - memcpy(iov[i].iov_base + (iov_off - iovec_off), buf + buf_off, len); - - buf_off += len; - iov_off += len; - size -= len; + for (i = 0, done = 0; (offset || done < bytes) && i < iov_cnt; i++) { + if (offset < iov[i].iov_len) { + size_t len = MIN(iov[i].iov_len - offset, bytes - done); + memcpy(iov[i].iov_base + offset, buf + done, len); + done += len; + offset = 0; + } else { + offset -= iov[i].iov_len; } - iovec_off += iov[i].iov_len; } - return buf_off; + assert(offset == 0); + return done; } size_t iov_to_buf(const struct iovec *iov, const unsigned int iov_cnt, - void *buf, size_t iov_off, size_t size) + size_t offset, void *buf, size_t bytes) { - uint8_t *ptr; - size_t iovec_off, buf_off; + size_t done; unsigned int i; - - ptr = buf; - iovec_off = 0; - buf_off = 0; - for (i = 0; i < iov_cnt && size; i++) { - if (iov_off < (iovec_off + iov[i].iov_len)) { - size_t len = MIN((iovec_off + iov[i].iov_len) - iov_off , size); - - memcpy(ptr + buf_off, iov[i].iov_base + (iov_off - iovec_off), len); - - buf_off += len; - iov_off += len; - size -= len; + for (i = 0, done = 0; (offset || done < bytes) && i < iov_cnt; i++) { + if (offset < iov[i].iov_len) { + size_t len = MIN(iov[i].iov_len - offset, bytes - done); + memcpy(buf + done, iov[i].iov_base + offset, len); + done += len; + offset = 0; + } else { + offset -= iov[i].iov_len; } - iovec_off += iov[i].iov_len; } - return buf_off; + assert(offset == 0); + return done; } -size_t iov_clear(const struct iovec *iov, const unsigned int iov_cnt, - size_t iov_off, size_t size) +size_t iov_memset(const struct iovec *iov, const unsigned int iov_cnt, + size_t offset, int fillc, size_t bytes) { - size_t iovec_off, buf_off; + size_t done; unsigned int i; - - iovec_off = 0; - buf_off = 0; - for (i = 0; i < iov_cnt && size; i++) { - if (iov_off < (iovec_off + iov[i].iov_len)) { - size_t len = MIN((iovec_off + iov[i].iov_len) - iov_off , size); - - memset(iov[i].iov_base + (iov_off - iovec_off), 0, len); - - buf_off += len; - iov_off += len; - size -= len; + for (i = 0, done = 0; (offset || done < bytes) && i < iov_cnt; i++) { + if (offset < iov[i].iov_len) { + size_t len = MIN(iov[i].iov_len - offset, bytes - done); + memset(iov[i].iov_base + offset, fillc, len); + done += len; + offset = 0; + } else { + offset -= iov[i].iov_len; } - iovec_off += iov[i].iov_len; } - return buf_off; + assert(offset == 0); + return done; } size_t iov_size(const struct iovec *iov, const unsigned int iov_cnt) @@ -100,6 +95,101 @@ size_t iov_size(const struct iovec *iov, const unsigned int iov_cnt) return len; } +/* helper function for iov_send_recv() */ +static ssize_t +do_send_recv(int sockfd, struct iovec *iov, unsigned iov_cnt, bool do_send) +{ +#if defined CONFIG_IOVEC && defined CONFIG_POSIX + ssize_t ret; + struct msghdr msg; + memset(&msg, 0, sizeof(msg)); + msg.msg_iov = iov; + msg.msg_iovlen = iov_cnt; + do { + ret = do_send + ? sendmsg(sockfd, &msg, 0) + : recvmsg(sockfd, &msg, 0); + } while (ret < 0 && errno == EINTR); + return ret; +#else + /* else send piece-by-piece */ + /*XXX Note: windows has WSASend() and WSARecv() */ + unsigned i; + size_t count = 0; + for (i = 0; i < iov_cnt; ++i) { + ssize_t r = do_send + ? send(sockfd, iov[i].iov_base, iov[i].iov_len, 0) + : recv(sockfd, iov[i].iov_base, iov[i].iov_len, 0); + if (r > 0) { + ret += r; + } else if (!r) { + break; + } else if (errno == EINTR) { + continue; + } else { + /* else it is some "other" error, + * only return if there was no data processed. */ + if (ret == 0) { + return -1; + } + break; + } + } + return count; +#endif +} + +ssize_t iov_send_recv(int sockfd, struct iovec *iov, unsigned iov_cnt, + size_t offset, size_t bytes, + bool do_send) +{ + ssize_t ret; + unsigned si, ei; /* start and end indexes */ + + /* Find the start position, skipping `offset' bytes: + * first, skip all full-sized vector elements, */ + for (si = 0; si < iov_cnt && offset >= iov[si].iov_len; ++si) { + offset -= iov[si].iov_len; + } + if (offset) { + assert(si < iov_cnt); + /* second, skip `offset' bytes from the (now) first element, + * undo it on exit */ + iov[si].iov_base += offset; + iov[si].iov_len -= offset; + } + /* Find the end position skipping `bytes' bytes: */ + /* first, skip all full-sized elements */ + for (ei = si; ei < iov_cnt && iov[ei].iov_len <= bytes; ++ei) { + bytes -= iov[ei].iov_len; + } + if (bytes) { + /* second, fixup the last element, and remember + * the length we've cut from the end of it in `bytes' */ + size_t tail; + assert(ei < iov_cnt); + assert(iov[ei].iov_len > bytes); + tail = iov[ei].iov_len - bytes; + iov[ei].iov_len = bytes; + bytes = tail; /* bytes is now equal to the tail size */ + ++ei; + } + + ret = do_send_recv(sockfd, iov + si, ei - si, do_send); + + /* Undo the changes above */ + if (offset) { + iov[si].iov_base -= offset; + iov[si].iov_len += offset; + } + if (bytes) { + iov[ei-1].iov_len += bytes; + } + + return ret; +} + + void iov_hexdump(const struct iovec *iov, const unsigned int iov_cnt, FILE *fp, const char *prefix, size_t limit) { |