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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/core/iovec.c
downloadlinux-2.6.38-lt-ux500-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'net/core/iovec.c')
-rw-r--r--net/core/iovec.c239
1 files changed, 239 insertions, 0 deletions
diff --git a/net/core/iovec.c b/net/core/iovec.c
new file mode 100644
index 00000000000..d57ace949ab
--- /dev/null
+++ b/net/core/iovec.c
@@ -0,0 +1,239 @@
+/*
+ * iovec manipulation routines.
+ *
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Fixes:
+ * Andrew Lunn : Errors in iovec copying.
+ * Pedro Roque : Added memcpy_fromiovecend and
+ * csum_..._fromiovecend.
+ * Andi Kleen : fixed error handling for 2.1
+ * Alexey Kuznetsov: 2.1 optimisations
+ * Andi Kleen : Fix csum*fromiovecend for IPv6.
+ */
+
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/net.h>
+#include <linux/in6.h>
+#include <asm/uaccess.h>
+#include <asm/byteorder.h>
+#include <net/checksum.h>
+#include <net/sock.h>
+
+/*
+ * Verify iovec. The caller must ensure that the iovec is big enough
+ * to hold the message iovec.
+ *
+ * Save time not doing verify_area. copy_*_user will make this work
+ * in any case.
+ */
+
+int verify_iovec(struct msghdr *m, struct iovec *iov, char *address, int mode)
+{
+ int size, err, ct;
+
+ if (m->msg_namelen) {
+ if (mode == VERIFY_READ) {
+ err = move_addr_to_kernel(m->msg_name, m->msg_namelen,
+ address);
+ if (err < 0)
+ return err;
+ }
+ m->msg_name = address;
+ } else {
+ m->msg_name = NULL;
+ }
+
+ size = m->msg_iovlen * sizeof(struct iovec);
+ if (copy_from_user(iov, m->msg_iov, size))
+ return -EFAULT;
+
+ m->msg_iov = iov;
+ err = 0;
+
+ for (ct = 0; ct < m->msg_iovlen; ct++) {
+ err += iov[ct].iov_len;
+ /*
+ * Goal is not to verify user data, but to prevent returning
+ * negative value, which is interpreted as errno.
+ * Overflow is still possible, but it is harmless.
+ */
+ if (err < 0)
+ return -EMSGSIZE;
+ }
+
+ return err;
+}
+
+/*
+ * Copy kernel to iovec. Returns -EFAULT on error.
+ *
+ * Note: this modifies the original iovec.
+ */
+
+int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len)
+{
+ while (len > 0) {
+ if (iov->iov_len) {
+ int copy = min_t(unsigned int, iov->iov_len, len);
+ if (copy_to_user(iov->iov_base, kdata, copy))
+ return -EFAULT;
+ kdata += copy;
+ len -= copy;
+ iov->iov_len -= copy;
+ iov->iov_base += copy;
+ }
+ iov++;
+ }
+
+ return 0;
+}
+
+/*
+ * Copy iovec to kernel. Returns -EFAULT on error.
+ *
+ * Note: this modifies the original iovec.
+ */
+
+int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len)
+{
+ while (len > 0) {
+ if (iov->iov_len) {
+ int copy = min_t(unsigned int, len, iov->iov_len);
+ if (copy_from_user(kdata, iov->iov_base, copy))
+ return -EFAULT;
+ len -= copy;
+ kdata += copy;
+ iov->iov_base += copy;
+ iov->iov_len -= copy;
+ }
+ iov++;
+ }
+
+ return 0;
+}
+
+/*
+ * For use with ip_build_xmit
+ */
+int memcpy_fromiovecend(unsigned char *kdata, struct iovec *iov, int offset,
+ int len)
+{
+ /* Skip over the finished iovecs */
+ while (offset >= iov->iov_len) {
+ offset -= iov->iov_len;
+ iov++;
+ }
+
+ while (len > 0) {
+ u8 __user *base = iov->iov_base + offset;
+ int copy = min_t(unsigned int, len, iov->iov_len - offset);
+
+ offset = 0;
+ if (copy_from_user(kdata, base, copy))
+ return -EFAULT;
+ len -= copy;
+ kdata += copy;
+ iov++;
+ }
+
+ return 0;
+}
+
+/*
+ * And now for the all-in-one: copy and checksum from a user iovec
+ * directly to a datagram
+ * Calls to csum_partial but the last must be in 32 bit chunks
+ *
+ * ip_build_xmit must ensure that when fragmenting only the last
+ * call to this function will be unaligned also.
+ */
+int csum_partial_copy_fromiovecend(unsigned char *kdata, struct iovec *iov,
+ int offset, unsigned int len, int *csump)
+{
+ int csum = *csump;
+ int partial_cnt = 0, err = 0;
+
+ /* Skip over the finished iovecs */
+ while (offset >= iov->iov_len) {
+ offset -= iov->iov_len;
+ iov++;
+ }
+
+ while (len > 0) {
+ u8 __user *base = iov->iov_base + offset;
+ int copy = min_t(unsigned int, len, iov->iov_len - offset);
+
+ offset = 0;
+
+ /* There is a remnant from previous iov. */
+ if (partial_cnt) {
+ int par_len = 4 - partial_cnt;
+
+ /* iov component is too short ... */
+ if (par_len > copy) {
+ if (copy_from_user(kdata, base, copy))
+ goto out_fault;
+ kdata += copy;
+ base += copy;
+ partial_cnt += copy;
+ len -= copy;
+ iov++;
+ if (len)
+ continue;
+ *csump = csum_partial(kdata - partial_cnt,
+ partial_cnt, csum);
+ goto out;
+ }
+ if (copy_from_user(kdata, base, par_len))
+ goto out_fault;
+ csum = csum_partial(kdata - partial_cnt, 4, csum);
+ kdata += par_len;
+ base += par_len;
+ copy -= par_len;
+ len -= par_len;
+ partial_cnt = 0;
+ }
+
+ if (len > copy) {
+ partial_cnt = copy % 4;
+ if (partial_cnt) {
+ copy -= partial_cnt;
+ if (copy_from_user(kdata + copy, base + copy,
+ partial_cnt))
+ goto out_fault;
+ }
+ }
+
+ if (copy) {
+ csum = csum_and_copy_from_user(base, kdata, copy,
+ csum, &err);
+ if (err)
+ goto out;
+ }
+ len -= copy + partial_cnt;
+ kdata += copy + partial_cnt;
+ iov++;
+ }
+ *csump = csum;
+out:
+ return err;
+
+out_fault:
+ err = -EFAULT;
+ goto out;
+}
+
+EXPORT_SYMBOL(csum_partial_copy_fromiovecend);
+EXPORT_SYMBOL(memcpy_fromiovec);
+EXPORT_SYMBOL(memcpy_fromiovecend);
+EXPORT_SYMBOL(memcpy_toiovec);