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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:51:24 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:51:24 +0000 |
commit | f7548d6d28c313cf80e6f3ef89aed16a19815df1 (patch) | |
tree | a3f6f2a3f247293bee59ecd28e8cd8ceb6ca064a /src/lib/sendfile-util.c | |
parent | Initial commit. (diff) | |
download | dovecot-upstream.tar.xz dovecot-upstream.zip |
Adding upstream version 1:2.3.19.1+dfsg1.upstream/1%2.3.19.1+dfsg1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/lib/sendfile-util.c')
-rw-r--r-- | src/lib/sendfile-util.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/src/lib/sendfile-util.c b/src/lib/sendfile-util.c new file mode 100644 index 0000000..662285b --- /dev/null +++ b/src/lib/sendfile-util.c @@ -0,0 +1,137 @@ +/* Copyright (c) 2002-2018 Dovecot authors, see the included COPYING file */ + +/* kludge a bit to remove _FILE_OFFSET_BITS definition from config.h. + It's required to be able to include sys/sendfile.h with Linux. */ +#include "config.h" +#undef HAVE_CONFIG_H + +#ifdef HAVE_LINUX_SENDFILE +# undef _FILE_OFFSET_BITS +#endif + +#include "lib.h" +#include "sendfile-util.h" + +#ifdef HAVE_LINUX_SENDFILE + +#include <sys/sendfile.h> + +ssize_t safe_sendfile(int out_fd, int in_fd, uoff_t *offset, size_t count) +{ + /* REMEMBER: uoff_t and off_t may not be of same size. */ + off_t safe_offset; + ssize_t ret; + + i_assert(count > 0); + + /* make sure given offset fits into off_t */ + if (sizeof(off_t) * CHAR_BIT == 32) { + /* 32bit off_t */ + if (*offset >= 2147483647L) { + errno = EINVAL; + return -1; + } + if (count > 2147483647L - *offset) + count = 2147483647L - *offset; + } else { + /* they're most likely the same size. if not, fix this + code later */ + i_assert(sizeof(off_t) == sizeof(uoff_t)); + + if (*offset >= OFF_T_MAX) { + errno = EINVAL; + return -1; + } + if (count > OFF_T_MAX - *offset) + count = OFF_T_MAX - *offset; + } + + safe_offset = (off_t)*offset; + ret = sendfile(out_fd, in_fd, &safe_offset, count); + /* ret=0 : trying to read past EOF */ + *offset = (uoff_t)safe_offset; + return ret; +} + +#elif defined(HAVE_FREEBSD_SENDFILE) + +#include <sys/socket.h> +#include <sys/uio.h> + +ssize_t safe_sendfile(int out_fd, int in_fd, uoff_t *offset, size_t count) +{ + struct sf_hdtr hdtr; + off_t sbytes; + int ret; + + /* if count=0 is passed to sendfile(), it sends everything + from in_fd until EOF. We don't want that. */ + i_assert(count > 0); + i_assert(count <= SSIZE_T_MAX); + + i_zero(&hdtr); + ret = sendfile(in_fd, out_fd, *offset, count, &hdtr, &sbytes, 0); + + *offset += sbytes; + + if (ret == 0 || (ret < 0 && errno == EAGAIN && sbytes > 0)) + return (ssize_t)sbytes; + else { + if (errno == ENOTSOCK) { + /* out_fd wasn't a socket. behave as if sendfile() + wasn't supported at all. */ + errno = EINVAL; + } + return -1; + } +} + +#elif defined (HAVE_SOLARIS_SENDFILE) + +#include <sys/sendfile.h> +#include "net.h" + +ssize_t safe_sendfile(int out_fd, int in_fd, uoff_t *offset, size_t count) +{ + ssize_t ret; + off_t s_offset; + + i_assert(count > 0); + i_assert(count <= SSIZE_T_MAX); + + /* NOTE: if outfd is not a socket, some Solaris versions will + kernel panic */ + + s_offset = (off_t)*offset; + ret = sendfile(out_fd, in_fd, &s_offset, count); + + if (ret < 0) { + /* if remote is gone, EPIPE is returned */ + if (errno == EINVAL) { + /* most likely trying to read past EOF */ + ret = 0; + } else if (errno == EAFNOSUPPORT || errno == EOPNOTSUPP) { + /* not supported, return Linux-like EINVAL so caller + sees only consistent errnos. */ + errno = EINVAL; + } else if (s_offset != (off_t)*offset) { + /* some data was sent, return it */ + i_assert(s_offset > (off_t)*offset); + ret = s_offset - (off_t)*offset; + } + } + *offset = (uoff_t)s_offset; + i_assert(ret < 0 || (size_t)ret <= count); + return ret; +} + +#else +ssize_t safe_sendfile(int out_fd ATTR_UNUSED, int in_fd ATTR_UNUSED, + uoff_t *offset ATTR_UNUSED, + size_t count ATTR_UNUSED) +{ + errno = EINVAL; + return -1; +} + +#endif |