/* * net/tipc/msg.c: TIPC message header routines * * Copyright (c) 2000-2006, 2014-2015, Ericsson AB * Copyright (c) 2005, 2010-2011, Wind River Systems * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the names of the copyright holders nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * Alternatively, this software may be distributed under the terms of the * GNU General Public License ("GPL") version 2 as published by the Free * Software Foundation. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include <net/sock.h>#include "core.h"#include "msg.h"#include "addr.h"#include "name_table.h" #define MAX_FORWARD_SIZE 1024#define BUF_HEADROOM (LL_MAX_HEADER + 48)#define BUF_TAILROOM 16 static unsigned int align(unsigned int i){ return (i + 3) & ~3u;} /** * tipc_buf_acquire - creates a TIPC message buffer * @size: message size (including TIPC header) * * Returns a new buffer with data pointers set to the specified size. * * NOTE: Headroom is reserved to allow prepending of a data link header. * There may also be unrequested tailroom present at the buffer's end. */struct sk_buff *tipc_buf_acquire(u32 size, gfp_t gfp){ struct sk_buff *skb; unsigned int buf_size = (BUF_HEADROOM + size + 3) & ~3u; skb = alloc_skb_fclone(buf_size, gfp); if (skb) { skb_reserve(skb, BUF_HEADROOM); skb_put(skb, size); skb->next = NULL; } return skb;} void tipc_msg_init(u32 own_node, struct tipc_msg *m, u32 user, u32 type, u32 hsize, u32 dnode){ memset(m, 0, hsize); msg_set_version(m); msg_set_user(m, user); msg_set_hdr_sz(m, hsize); msg_set_size(m, hsize); msg_set_prevnode(m, own_node); msg_set_type(m, type); if (hsize > SHORT_H_SIZE) { msg_set_orignode(m, own_node); msg_set_destnode(m, dnode); }} struct sk_buff *tipc_msg_create(uint user, uint type, uint hdr_sz, uint data_sz, u32 dnode, u32 onode, u32 dport, u32 oport, int errcode){ struct tipc_msg *msg; struct sk_buff *buf; buf = tipc_buf_acquire(hdr_sz + data_sz, GFP_ATOMIC); if (unlikely(!buf)) return NULL; msg = buf_msg(buf); tipc_msg_init(onode, msg, user, type, hdr_sz, dnode); msg_set_size(msg, hdr_sz + data_sz); msg_set_origport(msg, oport); msg_set_destport(msg, dport); msg_set_errcode(msg, errcode); if (hdr_sz > SHORT_H_SIZE) { msg_set_orignode(msg, onode); msg_set_destnode(msg, dnode); } return buf;} /* tipc_buf_append(): Append a buffer to the fragment list of another buffer * @*headbuf: in: NULL for first frag, otherwise value returned from prev call * out: set when successful non-complete reassembly, otherwise NULL * @*buf: in: the buffer to append. Always defined * out: head buf after successful complete reassembly, otherwise NULL * Returns 1 when reassembly complete, otherwise 0 */int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf){ struct sk_buff *head = *headbuf; struct sk_buff *frag = *buf; struct sk_buff *tail = NULL; struct tipc_msg *msg; u32 fragid; int delta; bool headstolen; if (!frag) goto err; msg = buf_msg(frag); fragid = msg_type(msg); frag->next = NULL; skb_pull(frag, msg_hdr_sz(msg)); if (fragid == FIRST_FRAGMENT) { if (unlikely(head)) goto err; if (unlikely(skb_unclone(frag, GFP_ATOMIC))) goto err; head = *headbuf = frag; *buf = NULL; TIPC_SKB_CB(head)->tail = NULL; if (skb_is_nonlinear(head)) { skb_walk_frags(head, tail) { TIPC_SKB_CB(head)->tail = tail; } } else { skb_frag_list_init(head); } return 0; } if (!head) goto err; if (skb_try_coalesce(head, frag, &headstolen, &delta)) { kfree_skb_partial(frag, headstolen); } else { tail = TIPC_SKB_CB(head)->tail; if (!skb_has_frag_list(head)) skb_shinfo(head)->frag_list = frag; else tail->next = frag; head->truesize += frag->truesize; head->data_len += frag->len; head->len += frag->len; TIPC_SKB_CB(head)->tail = frag; } if (fragid == LAST_FRAGMENT) { TIPC_SKB_CB(head)->validated = false; if (unlikely(!tipc_msg_validate(&head))) goto err; *buf = head; TIPC_SKB_CB(head)->tail = NULL; *headbuf = NULL; return 1; } *buf = NULL; return 0;err: kfree_skb(*buf); kfree_skb(*headbuf); *buf = *headbuf = NULL; return 0;} /* tipc_msg_validate - validate basic format of received message * * This routine ensures a TIPC message has an acceptable header, and at least * as much data as the header indicates it should. The routine also ensures * that the entire message header is stored in the main fragment of the message * buffer, to simplify future access to message header fields. * * Note: Having extra info present in the message header or data areas is OK. * TIPC will ignore the excess, under the assumption that it is optional info * introduced by a later release of the protocol. */bool tipc_msg_validate(struct sk_buff **_skb){ struct sk_buff *skb = *_skb; struct tipc_msg *hdr; int msz, hsz; /* Ensure that flow control ratio condition is satisfied */ if (unlikely(skb->truesize / buf_roundup_len(skb) >= 4)) { skb = skb_copy_expand(skb, BUF_HEADROOM, 0, GFP_ATOMIC); if (!skb) return false; kfree_skb(*_skb); *_skb = skb; } if (unlikely(TIPC_SKB_CB(skb)->validated)) return true; if (unlikely(!pskb_may_pull(skb, MIN_H_SIZE))) return false; hsz = msg_hdr_sz(buf_msg(skb)); if (unlikely(hsz < MIN_H_SIZE) || (hsz > MAX_H_SIZE)) return false; if (unlikely(!pskb_may_pull(skb, hsz))) return false; hdr = buf_msg(skb); if (unlikely(msg_version(hdr) != TIPC_VERSION)) return false; msz = msg_size(hdr); if (unlikely(msz < hsz)) return false; if (unlikely((msz - hsz) > TIPC_MAX_USER_MSG_SIZE)) return false; if (unlikely(skb->len < msz)) return false; TIPC_SKB_CB(skb)->validated = true; return true;} /** * tipc_msg_fragment - build a fragment skb list for TIPC message * * @skb: TIPC message skb * @hdr: internal msg header to be put on the top of the fragments * @pktmax: max size of a fragment incl. the header * @frags: returned fragment skb list * * Returns 0 if the fragmentation is successful, otherwise: -EINVAL * or -ENOMEM */int tipc_msg_fragment(struct sk_buff *skb, const struct tipc_msg *hdr, int pktmax, struct sk_buff_head *frags){ int pktno, nof_fragms, dsz, dmax, eat; struct tipc_msg *_hdr; struct sk_buff *_skb; u8 *data; /* Non-linear buffer? */ if (skb_linearize(skb)) return -ENOMEM; data = (u8 *)skb->data; dsz = msg_size(buf_msg(skb)); dmax = pktmax - INT_H_SIZE; if (dsz <= dmax || !dmax) return -EINVAL; nof_fragms = dsz / dmax + 1; for (pktno = 1; pktno <= nof_fragms; pktno++) { if (pktno < nof_fragms) eat = dmax; else eat = dsz % dmax; /* Allocate a new fragment */ _skb = tipc_buf_acquire(INT_H_SIZE + eat, GFP_ATOMIC); if (!_skb) goto error; skb_orphan(_skb); __skb_queue_tail(frags, _skb); /* Copy header & data to the fragment */ skb_copy_to_linear_data(_skb, hdr, INT_H_SIZE); skb_copy_to_linear_data_offset(_skb, INT_H_SIZE, data, eat); data += eat; /* Update the fragment's header */ _hdr = buf_msg(_skb); msg_set_fragm_no(_hdr, pktno); msg_set_nof_fragms(_hdr, nof_fragms); msg_set_size(_hdr, INT_H_SIZE + eat); } return 0; error: __skb_queue_purge(frags); __skb_queue_head_init(frags); return -ENOMEM;} /** * tipc_msg_build - create buffer chain containing specified header and data * @mhdr: Message header, to be prepended to data * @m: User message * @dsz: Total length of user data * @pktmax: Max packet size that can be used * @list: Buffer or chain of buffers to be returned to caller * * Note that the recursive call we are making here is safe, since it can * logically go only one further level down. * * Returns message data size or errno: -ENOMEM, -EFAULT */int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m, int offset, int dsz, int pktmax, struct sk_buff_head *list){ int mhsz = msg_hdr_sz(mhdr); struct tipc_msg pkthdr; int msz = mhsz + dsz; int pktrem = pktmax; struct sk_buff *skb; int drem = dsz; int pktno = 1; char *pktpos; int pktsz; int rc; msg_set_size(mhdr, msz); /* No fragmentation needed? */ if (likely(msz <= pktmax)) { skb = tipc_buf_acquire(msz, GFP_KERNEL); /* Fall back to smaller MTU if node local message */ if (unlikely(!skb)) { if (pktmax != MAX_MSG_SIZE) return -ENOMEM; rc = tipc_msg_build(mhdr, m, offset, dsz, FB_MTU, list); if (rc != dsz) return rc; if (tipc_msg_assemble(list)) return dsz; return -ENOMEM; } skb_orphan(skb); __skb_queue_tail(list, skb); skb_copy_to_linear_data(skb, mhdr, mhsz); pktpos = skb->data + mhsz; if (copy_from_iter_full(pktpos, dsz, &m->msg_iter)) return dsz; rc = -EFAULT; goto error; } /* Prepare reusable fragment header */ tipc_msg_init(msg_prevnode(mhdr), &pkthdr, MSG_FRAGMENTER, FIRST_FRAGMENT, INT_H_SIZE, msg_destnode(mhdr)); msg_set_size(&pkthdr, pktmax); msg_set_fragm_no(&pkthdr, pktno); msg_set_importance(&pkthdr, msg_importance(mhdr)); /* Prepare first fragment */ skb = tipc_buf_acquire(pktmax, GFP_KERNEL); if (!skb) return -ENOMEM; skb_orphan(skb); __skb_queue_tail(list, skb); pktpos = skb->data; skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE); pktpos += INT_H_SIZE; pktrem -= INT_H_SIZE; skb_copy_to_linear_data_offset(skb, INT_H_SIZE, mhdr, mhsz); pktpos += mhsz; pktrem -= mhsz; do { if (drem < pktrem) pktrem = drem; if (!copy_from_iter_full(pktpos, pktrem, &m->msg_iter)) { rc = -EFAULT; goto error; } drem -= pktrem; if (!drem) break; /* Prepare new fragment: */ if (drem < (pktmax - INT_H_SIZE)) pktsz = drem + INT_H_SIZE; else pktsz = pktmax; skb = tipc_buf_acquire(pktsz, GFP_KERNEL); if (!skb) { rc = -ENOMEM; goto error; } skb_orphan(skb); __skb_queue_tail(list, skb); msg_set_type(&pkthdr, FRAGMENT); msg_set_size(&pkthdr, pktsz); msg_set_fragm_no(&pkthdr, ++pktno); skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE); pktpos = skb->data + INT_H_SIZE; pktrem = pktsz - INT_H_SIZE; } while (1); msg_set_type(buf_msg(skb), LAST_FRAGMENT); return dsz;error: __skb_queue_purge(list); __skb_queue_head_init(list); return rc;} /** * tipc_msg_bundle(): Append contents of a buffer to tail of an existing one * @skb: the buffer to append to ("bundle") * @msg: message to be appended * @mtu: max allowable size for the bundle buffer * Consumes buffer if successful * Returns true if bundling could be performed, otherwise false */bool tipc_msg_bundle(struct sk_buff *skb, struct tipc_msg *msg, u32 mtu){ struct tipc_msg *bmsg; unsigned int bsz; unsigned int msz = msg_size(msg); u32 start, pad; u32 max = mtu - INT_H_SIZE; if (likely(msg_user(msg) == MSG_FRAGMENTER)) return false; if (!skb) return false; bmsg = buf_msg(skb); bsz = msg_size(bmsg); start = align(bsz); pad = start - bsz; if (unlikely(msg_user(msg) == TUNNEL_PROTOCOL)) return false; if (unlikely(msg_user(msg) == BCAST_PROTOCOL)) return false; if (unlikely(msg_user(bmsg) != MSG_BUNDLER)) return false; if (unlikely(skb_tailroom(skb) < (pad + msz))) return false; if (unlikely(max < (start + msz))) return false; if ((msg_importance(msg) < TIPC_SYSTEM_IMPORTANCE) && (msg_importance(bmsg) == TIPC_SYSTEM_IMPORTANCE)) return false; skb_put(skb, pad + msz); skb_copy_to_linear_data_offset(skb, start, msg, msz); msg_set_size(bmsg, start + msz); msg_set_msgcnt(bmsg, msg_msgcnt(bmsg) + 1); return true;} /** * tipc_msg_extract(): extract bundled inner packet from buffer * @skb: buffer to be extracted from. * @iskb: extracted inner buffer, to be returned * @pos: position in outer message of msg to be extracted. * Returns position of next msg * Consumes outer buffer when last packet extracted * Returns true when when there is an extracted buffer, otherwise false */bool tipc_msg_extract(struct sk_buff *skb, struct sk_buff **iskb, int *pos){ struct tipc_msg *hdr, *ihdr; int imsz; *iskb = NULL; if (unlikely(skb_linearize(skb))) goto none; hdr = buf_msg(skb); if (unlikely(*pos > (msg_data_sz(hdr) - MIN_H_SIZE))) goto none; ihdr = (struct tipc_msg *)(msg_data(hdr) + *pos); imsz = msg_size(ihdr); if ((*pos + imsz) > msg_data_sz(hdr)) goto none; *iskb = tipc_buf_acquire(imsz, GFP_ATOMIC); if (!*iskb) goto none; skb_copy_to_linear_data(*iskb, ihdr, imsz); if (unlikely(!tipc_msg_validate(iskb)))Lines 1–500 of 791. 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/* * net/tipc/msg.c: TIPC message header routines * * Copyright (c) 2000-2006, 2014-2015, Ericsson AB * Copyright (c) 2005, 2010-2011, Wind River Systems * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the names of the copyright holders nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * Alternatively, this software may be distributed under the terms of the * GNU General Public License ("GPL") version 2 as published by the Free * Software Foundation. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include <net/sock.h> #include "core.h" #include "msg.h" #include "addr.h" #include "name_table.h" #define MAX_FORWARD_SIZE 1024 #define BUF_HEADROOM (LL_MAX_HEADER + 48) #define BUF_TAILROOM 16 static unsigned int align(unsigned int i) { return (i + 3) & ~3u; } /** * tipc_buf_acquire - creates a TIPC message buffer * @size: message size (including TIPC header) * * Returns a new buffer with data pointers set to the specified size. * * NOTE: Headroom is reserved to allow prepending of a data link header. * There may also be unrequested tailroom present at the buffer's end. */ struct sk_buff *tipc_buf_acquire(u32 size, gfp_t gfp) { struct sk_buff *skb; unsigned int buf_size = (BUF_HEADROOM + size + 3) & ~3u; skb = alloc_skb_fclone(buf_size, gfp); if (skb) { skb_reserve(skb, BUF_HEADROOM); skb_put(skb, size); skb->next = NULL; } return skb; } void tipc_msg_init(u32 own_node, struct tipc_msg *m, u32 user, u32 type, u32 hsize, u32 dnode) { memset(m, 0, hsize); msg_set_version(m); msg_set_user(m, user); msg_set_hdr_sz(m, hsize); msg_set_size(m, hsize); msg_set_prevnode(m, own_node); msg_set_type(m, type); if (hsize > SHORT_H_SIZE) { msg_set_orignode(m, own_node); msg_set_destnode(m, dnode); } } struct sk_buff *tipc_msg_create(uint user, uint type, uint hdr_sz, uint data_sz, u32 dnode, u32 onode, u32 dport, u32 oport, int errcode) { struct tipc_msg *msg; struct sk_buff *buf; buf = tipc_buf_acquire(hdr_sz + data_sz, GFP_ATOMIC); if (unlikely(!buf)) return NULL; msg = buf_msg(buf); tipc_msg_init(onode, msg, user, type, hdr_sz, dnode); msg_set_size(msg, hdr_sz + data_sz); msg_set_origport(msg, oport); msg_set_destport(msg, dport); msg_set_errcode(msg, errcode); if (hdr_sz > SHORT_H_SIZE) { msg_set_orignode(msg, onode); msg_set_destnode(msg, dnode); } return buf; } /* tipc_buf_append(): Append a buffer to the fragment list of another buffer * @*headbuf: in: NULL for first frag, otherwise value returned from prev call * out: set when successful non-complete reassembly, otherwise NULL * @*buf: in: the buffer to append. Always defined * out: head buf after successful complete reassembly, otherwise NULL * Returns 1 when reassembly complete, otherwise 0 */ int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf) { struct sk_buff *head = *headbuf; struct sk_buff *frag = *buf; struct sk_buff *tail = NULL; struct tipc_msg *msg; u32 fragid; int delta; bool headstolen; if (!frag) goto err; msg = buf_msg(frag); fragid = msg_type(msg); frag->next = NULL; skb_pull(frag, msg_hdr_sz(msg)); if (fragid == FIRST_FRAGMENT) { if (unlikely(head)) goto err; if (unlikely(skb_unclone(frag, GFP_ATOMIC))) goto err; head = *headbuf = frag; *buf = NULL; TIPC_SKB_CB(head)->tail = NULL; if (skb_is_nonlinear(head)) { skb_walk_frags(head, tail) { TIPC_SKB_CB(head)->tail = tail; } } else { skb_frag_list_init(head); } return 0; } if (!head) goto err; if (skb_try_coalesce(head, frag, &headstolen, &delta)) { kfree_skb_partial(frag, headstolen); } else { tail = TIPC_SKB_CB(head)->tail; if (!skb_has_frag_list(head)) skb_shinfo(head)->frag_list = frag; else tail->next = frag; head->truesize += frag->truesize; head->data_len += frag->len; head->len += frag->len; TIPC_SKB_CB(head)->tail = frag; } if (fragid == LAST_FRAGMENT) { TIPC_SKB_CB(head)->validated = false; if (unlikely(!tipc_msg_validate(&head))) goto err; *buf = head; TIPC_SKB_CB(head)->tail = NULL; *headbuf = NULL; return 1; } *buf = NULL; return 0; err: kfree_skb(*buf); kfree_skb(*headbuf); *buf = *headbuf = NULL; return 0; } /* tipc_msg_validate - validate basic format of received message * * This routine ensures a TIPC message has an acceptable header, and at least * as much data as the header indicates it should. The routine also ensures * that the entire message header is stored in the main fragment of the message * buffer, to simplify future access to message header fields. * * Note: Having extra info present in the message header or data areas is OK. * TIPC will ignore the excess, under the assumption that it is optional info * introduced by a later release of the protocol. */ bool tipc_msg_validate(struct sk_buff **_skb) { struct sk_buff *skb = *_skb; struct tipc_msg *hdr; int msz, hsz; /* Ensure that flow control ratio condition is satisfied */ if (unlikely(skb->truesize / buf_roundup_len(skb) >= 4)) { skb = skb_copy_expand(skb, BUF_HEADROOM, 0, GFP_ATOMIC); if (!skb) return false; kfree_skb(*_skb); *_skb = skb; } if (unlikely(TIPC_SKB_CB(skb)->validated)) return true; if (unlikely(!pskb_may_pull(skb, MIN_H_SIZE))) return false; hsz = msg_hdr_sz(buf_msg(skb)); if (unlikely(hsz < MIN_H_SIZE) || (hsz > MAX_H_SIZE)) return false; if (unlikely(!pskb_may_pull(skb, hsz))) return false; hdr = buf_msg(skb); if (unlikely(msg_version(hdr) != TIPC_VERSION)) return false; msz = msg_size(hdr); if (unlikely(msz < hsz)) return false; if (unlikely((msz - hsz) > TIPC_MAX_USER_MSG_SIZE)) return false; if (unlikely(skb->len < msz)) return false; TIPC_SKB_CB(skb)->validated = true; return true; } /** * tipc_msg_fragment - build a fragment skb list for TIPC message * * @skb: TIPC message skb * @hdr: internal msg header to be put on the top of the fragments * @pktmax: max size of a fragment incl. the header * @frags: returned fragment skb list * * Returns 0 if the fragmentation is successful, otherwise: -EINVAL * or -ENOMEM */ int tipc_msg_fragment(struct sk_buff *skb, const struct tipc_msg *hdr, int pktmax, struct sk_buff_head *frags) { int pktno, nof_fragms, dsz, dmax, eat; struct tipc_msg *_hdr; struct sk_buff *_skb; u8 *data; /* Non-linear buffer? */ if (skb_linearize(skb)) return -ENOMEM; data = (u8 *)skb->data; dsz = msg_size(buf_msg(skb)); dmax = pktmax - INT_H_SIZE; if (dsz <= dmax || !dmax) return -EINVAL; nof_fragms = dsz / dmax + 1; for (pktno = 1; pktno <= nof_fragms; pktno++) { if (pktno < nof_fragms) eat = dmax; else eat = dsz % dmax; /* Allocate a new fragment */ _skb = tipc_buf_acquire(INT_H_SIZE + eat, GFP_ATOMIC); if (!_skb) goto error; skb_orphan(_skb); __skb_queue_tail(frags, _skb); /* Copy header & data to the fragment */ skb_copy_to_linear_data(_skb, hdr, INT_H_SIZE); skb_copy_to_linear_data_offset(_skb, INT_H_SIZE, data, eat); data += eat; /* Update the fragment's header */ _hdr = buf_msg(_skb); msg_set_fragm_no(_hdr, pktno); msg_set_nof_fragms(_hdr, nof_fragms); msg_set_size(_hdr, INT_H_SIZE + eat); } return 0; error: __skb_queue_purge(frags); __skb_queue_head_init(frags); return -ENOMEM; } /** * tipc_msg_build - create buffer chain containing specified header and data * @mhdr: Message header, to be prepended to data * @m: User message * @dsz: Total length of user data * @pktmax: Max packet size that can be used * @list: Buffer or chain of buffers to be returned to caller * * Note that the recursive call we are making here is safe, since it can * logically go only one further level down. * * Returns message data size or errno: -ENOMEM, -EFAULT */ int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m, int offset, int dsz, int pktmax, struct sk_buff_head *list) { int mhsz = msg_hdr_sz(mhdr); struct tipc_msg pkthdr; int msz = mhsz + dsz; int pktrem = pktmax; struct sk_buff *skb; int drem = dsz; int pktno = 1; char *pktpos; int pktsz; int rc; msg_set_size(mhdr, msz); /* No fragmentation needed? */ if (likely(msz <= pktmax)) { skb = tipc_buf_acquire(msz, GFP_KERNEL); /* Fall back to smaller MTU if node local message */ if (unlikely(!skb)) { if (pktmax != MAX_MSG_SIZE) return -ENOMEM; rc = tipc_msg_build(mhdr, m, offset, dsz, FB_MTU, list); if (rc != dsz) return rc; if (tipc_msg_assemble(list)) return dsz; return -ENOMEM; } skb_orphan(skb); __skb_queue_tail(list, skb); skb_copy_to_linear_data(skb, mhdr, mhsz); pktpos = skb->data + mhsz; if (copy_from_iter_full(pktpos, dsz, &m->msg_iter)) return dsz; rc = -EFAULT; goto error; } /* Prepare reusable fragment header */ tipc_msg_init(msg_prevnode(mhdr), &pkthdr, MSG_FRAGMENTER, FIRST_FRAGMENT, INT_H_SIZE, msg_destnode(mhdr)); msg_set_size(&pkthdr, pktmax); msg_set_fragm_no(&pkthdr, pktno); msg_set_importance(&pkthdr, msg_importance(mhdr)); /* Prepare first fragment */ skb = tipc_buf_acquire(pktmax, GFP_KERNEL); if (!skb) return -ENOMEM; skb_orphan(skb); __skb_queue_tail(list, skb); pktpos = skb->data; skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE); pktpos += INT_H_SIZE; pktrem -= INT_H_SIZE; skb_copy_to_linear_data_offset(skb, INT_H_SIZE, mhdr, mhsz); pktpos += mhsz; pktrem -= mhsz; do { if (drem < pktrem) pktrem = drem; if (!copy_from_iter_full(pktpos, pktrem, &m->msg_iter)) { rc = -EFAULT; goto error; } drem -= pktrem; if (!drem) break; /* Prepare new fragment: */ if (drem < (pktmax - INT_H_SIZE)) pktsz = drem + INT_H_SIZE; else pktsz = pktmax; skb = tipc_buf_acquire(pktsz, GFP_KERNEL); if (!skb) { rc = -ENOMEM; goto error; } skb_orphan(skb); __skb_queue_tail(list, skb); msg_set_type(&pkthdr, FRAGMENT); msg_set_size(&pkthdr, pktsz); msg_set_fragm_no(&pkthdr, ++pktno); skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE); pktpos = skb->data + INT_H_SIZE; pktrem = pktsz - INT_H_SIZE; } while (1); msg_set_type(buf_msg(skb), LAST_FRAGMENT); return dsz; error: __skb_queue_purge(list); __skb_queue_head_init(list); return rc; } /** * tipc_msg_bundle(): Append contents of a buffer to tail of an existing one * @skb: the buffer to append to ("bundle") * @msg: message to be appended * @mtu: max allowable size for the bundle buffer * Consumes buffer if successful * Returns true if bundling could be performed, otherwise false */ bool tipc_msg_bundle(struct sk_buff *skb, struct tipc_msg *msg, u32 mtu) { struct tipc_msg *bmsg; unsigned int bsz; unsigned int msz = msg_size(msg); u32 start, pad; u32 max = mtu - INT_H_SIZE; if (likely(msg_user(msg) == MSG_FRAGMENTER)) return false; if (!skb) return false; bmsg = buf_msg(skb); bsz = msg_size(bmsg); start = align(bsz); pad = start - bsz; if (unlikely(msg_user(msg) == TUNNEL_PROTOCOL)) return false; if (unlikely(msg_user(msg) == BCAST_PROTOCOL)) return false; if (unlikely(msg_user(bmsg) != MSG_BUNDLER)) return false; if (unlikely(skb_tailroom(skb) < (pad + msz))) return false; if (unlikely(max < (start + msz))) return false; if ((msg_importance(msg) < TIPC_SYSTEM_IMPORTANCE) && (msg_importance(bmsg) == TIPC_SYSTEM_IMPORTANCE)) return false; skb_put(skb, pad + msz); skb_copy_to_linear_data_offset(skb, start, msg, msz); msg_set_size(bmsg, start + msz); msg_set_msgcnt(bmsg, msg_msgcnt(bmsg) + 1); return true; } /** * tipc_msg_extract(): extract bundled inner packet from buffer * @skb: buffer to be extracted from. * @iskb: extracted inner buffer, to be returned * @pos: position in outer message of msg to be extracted. * Returns position of next msg * Consumes outer buffer when last packet extracted * Returns true when when there is an extracted buffer, otherwise false */ bool tipc_msg_extract(struct sk_buff *skb, struct sk_buff **iskb, int *pos) { struct tipc_msg *hdr, *ihdr; int imsz; *iskb = NULL; if (unlikely(skb_linearize(skb))) goto none; hdr = buf_msg(skb); if (unlikely(*pos > (msg_data_sz(hdr) - MIN_H_SIZE))) goto none; ihdr = (struct tipc_msg *)(msg_data(hdr) + *pos); imsz = msg_size(ihdr); if ((*pos + imsz) > msg_data_sz(hdr)) goto none; *iskb = tipc_buf_acquire(imsz, GFP_ATOMIC); if (!*iskb) goto none; skb_copy_to_linear_data(*iskb, ihdr, imsz); if (unlikely(!tipc_msg_validate(iskb)))