[1058] in linux-net channel archive
~s Sendmsg and other bits
daemon@ATHENA.MIT.EDU (Alan Cox)
Wed Sep 6 06:25:46 1995
Date: Tue, 5 Sep 1995 18:26:50 +0100
From: Alan Cox <alan@cymru.net>
To: linux-net@vger.rutgers.edu, torvalds@cs.Helsinki.FI
*
* Hopefully IP port masquerading now works
* TCP closing fix
* TCP RFC1122 compliance summary
* sendmsg/recvmsg kernel fault bugfix.
*
--// Brought to you via the worlds first SMP linux machine --------------------
-//_______ inux/SMP - sponsored by Caldera Inc http://www.caldera.com==========
/________/=====================================================================
------Alan Cox <alan@cymru.net>, Custom Linux development +44 1792 297292------
--- net/ipv4/ip.c.old2 Mon Sep 4 21:41:46 1995
+++ net/ipv4/ip.c Mon Sep 4 21:53:16 1995
@@ -1055,6 +1055,9 @@
unsigned long raddr; /* Router IP address */
#ifdef CONFIG_IP_FIREWALL
int fw_res = 0; /* Forwarding result */
+#ifdef CONFIG_IP_MASQUERADE
+ struct sk_buff *skb_in = skb; /* So we can remember if the masquerader did some swaps */
+#endif
/*
* See if we are allowed to forward this.
@@ -1295,10 +1298,22 @@
/*
* Tell the caller if their buffer is free.
- */
+ */
if(skb==skb2)
+ return 0;
+
+#ifdef CONFIG_IP_MASQUERADE
+ /*
+ * The original is free. Free our copy and
+ * tell the caller not to free.
+ */
+ if(skb!=skb_in)
+ {
+ kfree_skb(skb_in, FREE_WRITE);
return 0;
+ }
+#endif
return 1;
}
--- net/ipv4/tcp.c.old2 Mon Sep 4 22:03:31 1995
+++ net/ipv4/tcp.c Mon Sep 4 22:10:43 1995
@@ -22,47 +22,61 @@
* Fixes:
* Alan Cox : Numerous verify_area() calls
* Alan Cox : Set the ACK bit on a reset
- * Alan Cox : Stopped it crashing if it closed while sk->inuse=1
- * and was trying to connect (tcp_err()).
+ * Alan Cox : Stopped it crashing if it closed while
+ * sk->inuse=1 and was trying to connect
+ * (tcp_err()).
* Alan Cox : All icmp error handling was broken
* pointers passed where wrong and the
* socket was looked up backwards. Nobody
* tested any icmp error code obviously.
- * Alan Cox : tcp_err() now handled properly. It wakes people
- * on errors. select behaves and the icmp error race
+ * Alan Cox : tcp_err() now handled properly. It
+ * wakes people on errors. select
+ * behaves and the icmp error race
* has gone by moving it into sock.c
- * Alan Cox : tcp_reset() fixed to work for everything not just
- * packets for unknown sockets.
+ * Alan Cox : tcp_reset() fixed to work for
+ * everything not just packets for
+ * unknown sockets.
* Alan Cox : tcp option processing.
- * Alan Cox : Reset tweaked (still not 100%) [Had syn rule wrong]
+ * Alan Cox : Reset tweaked (still not 100%) [Had
+ * syn rule wrong]
* Herp Rosmanith : More reset fixes
- * Alan Cox : No longer acks invalid rst frames. Acking
- * any kind of RST is right out.
- * Alan Cox : Sets an ignore me flag on an rst receive
- * otherwise odd bits of prattle escape still
- * Alan Cox : Fixed another acking RST frame bug. Should stop
- * LAN workplace lockups.
- * Alan Cox : Some tidyups using the new skb list facilities
+ * Alan Cox : No longer acks invalid rst frames.
+ * Acking any kind of RST is right out.
+ * Alan Cox : Sets an ignore me flag on an rst
+ * receive otherwise odd bits of prattle
+ * escape still
+ * Alan Cox : Fixed another acking RST frame bug.
+ * Should stop LAN workplace lockups.
+ * Alan Cox : Some tidyups using the new skb list
+ * facilities
* Alan Cox : sk->keepopen now seems to work
* Alan Cox : Pulls options out correctly on accepts
* Alan Cox : Fixed assorted sk->rqueue->next errors
- * Alan Cox : PSH doesn't end a TCP read. Switched a bit to skb ops.
- * Alan Cox : Tidied tcp_data to avoid a potential nasty.
- * Alan Cox : Added some better commenting, as the tcp is hard to follow
+ * Alan Cox : PSH doesn't end a TCP read. Switched a
+ * bit to skb ops.
+ * Alan Cox : Tidied tcp_data to avoid a potential
+ * nasty.
+ * Alan Cox : Added some better commenting, as the
+ * tcp is hard to follow
* Alan Cox : Removed incorrect check for 20 * psh
* Michael O'Reilly : ack < copied bug fix.
* Johannes Stille : Misc tcp fixes (not all in yet).
* Alan Cox : FIN with no memory -> CRASH
- * Alan Cox : Added socket option proto entries. Also added awareness of them to accept.
+ * Alan Cox : Added socket option proto entries.
+ * Also added awareness of them to accept.
* Alan Cox : Added TCP options (SOL_TCP)
- * Alan Cox : Switched wakeup calls to callbacks, so the kernel can layer network sockets.
+ * Alan Cox : Switched wakeup calls to callbacks,
+ * so the kernel can layer network
+ * sockets.
* Alan Cox : Use ip_tos/ip_ttl settings.
* Alan Cox : Handle FIN (more) properly (we hope).
- * Alan Cox : RST frames sent on unsynchronised state ack error/
+ * Alan Cox : RST frames sent on unsynchronised
+ * state ack error.
* Alan Cox : Put in missing check for SYN bit.
* Alan Cox : Added tcp_select_window() aka NET2E
* window non shrink trick.
- * Alan Cox : Added a couple of small NET2E timer fixes
+ * Alan Cox : Added a couple of small NET2E timer
+ * fixes
* Charles Hedrick : TCP fixes
* Toomas Tamm : TCP window fixes
* Alan Cox : Small URG fix to rlogin ^C ack fight
@@ -75,21 +89,28 @@
* Adam Caldwell : Assorted timer/timing errors
* Matthew Dillon : Fixed another RST bug
* Alan Cox : Move to kernel side addressing changes.
- * Alan Cox : Beginning work on TCP fastpathing (not yet usable)
+ * Alan Cox : Beginning work on TCP fastpathing
+ * (not yet usable)
* Arnt Gulbrandsen: Turbocharged tcp_check() routine.
* Alan Cox : TCP fast path debugging
* Alan Cox : Window clamping
* Michael Riepe : Bug in tcp_check()
* Matt Dillon : More TCP improvements and RST bug fixes
- * Matt Dillon : Yet more small nasties remove from the TCP code
- * (Be very nice to this man if tcp finally works 100%) 8)
+ * Matt Dillon : Yet more small nasties remove from the
+ * TCP code (Be very nice to this man if
+ * tcp finally works 100%) 8)
* Alan Cox : BSD accept semantics.
* Alan Cox : Reset on closedown bug.
* Peter De Schrijver : ENOTCONN check missing in tcp_sendto().
- * Michael Pall : Handle select() after URG properly in all cases.
- * Michael Pall : Undo the last fix in tcp_read_urg() (multi URG PUSH broke rlogin).
- * Michael Pall : Fix the multi URG PUSH problem in tcp_readable(), select() after URG works now.
- * Michael Pall : recv(...,MSG_OOB) never blocks in the BSD api.
+ * Michael Pall : Handle select() after URG properly in
+ * all cases.
+ * Michael Pall : Undo the last fix in tcp_read_urg()
+ * (multi URG PUSH broke rlogin).
+ * Michael Pall : Fix the multi URG PUSH problem in
+ * tcp_readable(), select() after URG
+ * works now.
+ * Michael Pall : recv(...,MSG_OOB) never blocks in the
+ * BSD api.
* Alan Cox : Changed the semantics of sk->socket to
* fix a race and a signal problem with
* accept() and async I/O.
@@ -107,21 +128,23 @@
* Alan Cox : Reset tracing code.
* Alan Cox : Spurious resets on shutdown.
* Alan Cox : Giant 15 minute/60 second timer error
- * Alan Cox : Small whoops in selecting before an accept.
- * Alan Cox : Kept the state trace facility since it's
- * handy for debugging.
+ * Alan Cox : Small whoops in selecting before an
+ * accept.
+ * Alan Cox : Kept the state trace facility since
+ * it's handy for debugging.
* Alan Cox : More reset handler fixes.
- * Alan Cox : Started rewriting the code based on the RFC's
- * for other useful protocol references see:
- * Comer, KA9Q NOS, and for a reference on the
- * difference between specifications and how BSD
+ * Alan Cox : Started rewriting the code based on
+ * the RFC's for other useful protocol
+ * references see: Comer, KA9Q NOS, and
+ * for a reference on the difference
+ * between specifications and how BSD
* works see the 4.4lite source.
* A.N.Kuznetsov : Don't time wait on completion of tidy
* close.
* Linus Torvalds : Fin/Shutdown & copied_seq changes.
* Linus Torvalds : Fixed BSD port reuse to work first syn
- * Alan Cox : Reimplemented timers as per the RFC and using multiple
- * timers for sanity.
+ * Alan Cox : Reimplemented timers as per the RFC
+ * and using multiple timers for sanity.
* Alan Cox : Small bug fixes, and a lot of new
* comments.
* Alan Cox : Fixed dual reader crash by locking
@@ -150,6 +173,8 @@
* Alan Cox : Look up device on a retransmit - routes may
* change. Doesn't yet cope with MSS shrink right
* but its a start!
+ * Marc Tamsky : Closing in closing fixes.
+ * Mike Shaver : RFC1122 verifications
*
*
* To Fix:
@@ -218,6 +243,168 @@
* TCP_CLOSE socket is finished
*/
+/*
+ * RFC1122 status:
+ * NOTE: I'm not going to be doing comments in the code for this one except
+ * for violations and the like. tcp.c is just too big... If I say something
+ * "does?" or "doesn't?", it means I'm not sure, and will have to hash it out
+ * with Alan. -- MS 950903
+ *
+ * Use of PSH (4.2.2.2)
+ * MAY aggregate data sent without the PSH flag. (does)
+ * MAY queue data recieved without the PSH flag. (does)
+ * SHOULD collapse successive PSH flags when it packetizes data. (doesn't)
+ * MAY implement PSH on send calls. (doesn't, thus:)
+ * MUST NOT buffer data indefinitely (doesn't [1 second])
+ * MUST set PSH on last segment (does)
+ * MAY pass received PSH to application layer (doesn't)
+ * SHOULD send maximum-sized segment whenever possible. (almost always does)
+ *
+ * Window Size (4.2.2.3, 4.2.2.16)
+ * MUST treat window size as an unsigned number (does)
+ * SHOULD treat window size as a 32-bit number (does not)
+ * MUST NOT shrink window once it is offered (does not normally)
+ *
+ * Urgent Pointer (4.2.2.4)
+ * **MUST point urgent pointer to last byte of urgent data (not right
+ * after). (doesn't, to be like BSD)
+ * MUST inform application layer asynchronously of incoming urgent
+ * data. (does)
+ * MUST provide application with means of determining the amount of
+ * urgent data pending. (does)
+ * **MUST support urgent data sequence of arbitrary length. (doesn't, but
+ * it's sort of tricky to fix, as urg_ptr is a 16-bit quantity)
+ * [Follows BSD 1 byte of urgent data]
+ *
+ * TCP Options (4.2.2.5)
+ * MUST be able to recieve TCP options in any segment. (does)
+ * MUST ignore unsupported options (does)
+ *
+ * Maximum Segment Size Option (4.2.2.6)
+ * MUST implement both sending and receiving MSS. (does)
+ * SHOULD send an MSS with every SYN where recieve MSS != 536 (MAY send
+ * it always). (does, even when MSS == 536, which is legal)
+ * MUST assume MSS == 536 if no MSS received at connection setup (does)
+ * MUST calculate "effective send MSS" correctly:
+ * min(physical_MTU, remote_MSS+20) - sizeof(tcphdr) - sizeof(ipopts)
+ * (does - but allows operator override)
+ *
+ * TCP Checksum (4.2.2.7)
+ * MUST generate and check TCP checksum. (does)
+ *
+ * Initial Sequence Number Selection (4.2.2.8)
+ * MUST use the RFC 793 clock selection mechanism. (doesn't, but it's
+ * OK: RFC 793 specifies a 250KHz clock, while we use 1MHz, which is
+ * necessary for 10Mbps networks - and harder than BSD to spoof!)
+ *
+ * Simultaneous Open Attempts (4.2.2.10)
+ * MUST support simultaneous open attempts (does)
+ *
+ * Recovery from Old Duplicate SYN (4.2.2.11)
+ * MUST keep track of active vs. passive open (does)
+ *
+ * RST segment (4.2.2.12)
+ * SHOULD allow an RST segment to contain data (does, but doesn't do
+ * anything with it, which is standard)
+ *
+ * Closing a Connection (4.2.2.13)
+ * MUST inform application of whether connectin was closed by RST or
+ * normal close. (does)
+ * MAY allow "half-duplex" close (treat connection as closed for the
+ * local app, even before handshake is done). (does)
+ * MUST linger in TIME_WAIT for 2 * MSL (does)
+ *
+ * Retransmission Timeout (4.2.2.15)
+ * MUST implement Jacobson's slow start and congestion avoidance
+ * stuff. (does)
+ *
+ * Probing Zero Windows (4.2.2.17)
+ * MUST support probing of zero windows. (does)
+ * MAY keep offered window closed indefinitely. (does)
+ * MUST allow remote window to stay closed indefinitely. (does)
+ *
+ * Passive Open Calls (4.2.2.18)
+ * MUST NOT let new passive open affect other connections. (doesn't)
+ * MUST support passive opens (LISTENs) concurrently. (does)
+ *
+ * Time to Live (4.2.2.19)
+ * MUST make TCP TTL configurable. (does - IP_TTL option)
+ *
+ * Event Processing (4.2.2.20)
+ * SHOULD queue out-of-order segments. (does)
+ * MUST aggregate ACK segments whenever possible. (does but badly)
+ *
+ * Retransmission Timeout Calculation (4.2.3.1)
+ * MUST implement Karn's algorithm and Jacobson's algorithm for RTO
+ * calculation. (does, or at least explains them in the comments 8*b)
+ * SHOULD initialize RTO to 0 and RTT to 3. (does)
+ *
+ * When to Send an ACK Segment (4.2.3.2)
+ * SHOULD implement delayed ACK. (does not)
+ * MUST keep ACK delay < 0.5 sec. (N/A)
+ *
+ * When to Send a Window Update (4.2.3.3)
+ * MUST implement receiver-side SWS. (does)
+ *
+ * When to Send Data (4.2.3.4)
+ * MUST implement sender-side SWS. (does - imperfectly)
+ * SHOULD implement Nagle algorithm. (does)
+ *
+ * TCP Connection Failures (4.2.3.5)
+ * MUST handle excessive retransmissions "properly" (see the RFC). (does)
+ * SHOULD inform application layer of soft errors. (doesn't)
+ *
+ * TCP Keep-Alives (4.2.3.6)
+ * MAY provide keep-alives. (does)
+ * MUST make keep-alives configurable on a per-connection basis. (does)
+ * MUST default to no keep-alives. (does)
+ * **MUST make keep-alive interval configurable. (doesn't)
+ * **MUST make default keep-alive interval > 2 hours. (doesn't)
+ * MUST NOT interpret failure to ACK keep-alive packet as dead
+ * connection. (doesn't)
+ * SHOULD send keep-alive with no data. (does)
+ *
+ * TCP Multihoming (4.2.3.7)
+ * MUST get source address from IP layer before sending first
+ * SYN. (does)
+ * MUST use same local address for all segments of a connection. (does)
+ *
+ * IP Options (4.2.3.8)
+ * (I don't think the IP layer sees the IP options, yet.)
+ * MUST ignore unsupported IP options. (does, I guess 8*b)
+ * MAY support Time Stamp and Record Route. (doesn't)
+ * **MUST allow application to specify a source route. (doesn't?)
+ * **MUST allow receieved Source Route option to set route for all future
+ * segments on this connection. (doesn't, not that I think it's a
+ * huge problem)
+ *
+ * ICMP messages (4.2.3.9)
+ * MUST act on ICMP errors. (does)
+ * MUST slow transmission upon receipt of a Source Quench. (does)
+ * MUST NOT abort connection upon receipt of soft Destination
+ * Unreachables (0, 1, 5), Time Exceededs and Parameter
+ * Problems. (doesn't)
+ * SHOULD report soft Destination Unreachables etc. to the
+ * application. (doesn't)
+ * SHOULD abort connection upon receipt of hard Destination Unreachable
+ * messages (2, 3, 4). (does)
+ *
+ * Remote Address Validation (4.2.3.10)
+ * MUST reject as an error OPEN for invalid remote IP address. (does)
+ * MUST ignore SYN with invalid source address. (does)
+ * MUST silently discard incoming SYN for broadcast/multicast
+ * address. (does)
+ *
+ * Asynchronous Reports (4.2.4.1)
+ * **MUST provide mechanism for reporting soft errors to application
+ * layer. (doesn't)
+ *
+ * Type of Service (4.2.4.2)
+ * MUST allow application layer to set Type of Service. (does IP_TOS)
+ *
+ * (Whew. -- MS 950903)
+ **/
+
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/mm.h>
@@ -808,6 +995,8 @@
/*
* Retransmission
*/
+ sk->retransmits++;
+ sk->prot->retransmits++;
sk->prot->retransmit (sk, 0);
tcp_write_timeout(sk);
}
--- net/ipv4/ip_fw.c.old2 Mon Sep 4 21:41:59 1995
+++ net/ipv4/ip_fw.c Mon Sep 4 21:59:31 1995
@@ -38,9 +38,8 @@
* Fixes:
* Pauline Middelink : Added masquerading.
* Alan Cox : Fixed an error in the merge.
- *
- * TODO:
- * Fix the PORT spoof crash.
+ * Thomas Quinot : Fixed port spoofing.
+ * Alan Cox : Cleaned up retransmits in spoofing.
*
* All the real work was done by .....
*
@@ -586,7 +585,8 @@
unsigned long from;
unsigned short port;
struct ip_masq *ms;
- char buf[20]; /* xxx.xxx.xxx.xxx\r\n */
+ char buf[24]; /* xxx.xxx.xxx.xxx,ppp,ppp\000 */
+ int diff;
/*
* Adjust seq and ack_seq with delta-offset for
@@ -600,9 +600,9 @@
while (skb->len - ((unsigned char *)data - skb->h.raw) > 18)
{
- if (memcmp(data,"PORT ",5)!=0 && memcmp(data,"port ",5)!=0)
+ if (memcmp(data,"PORT ",5) && memcmp(data,"port ",5))
{
- data += 5;
+ data ++;
continue;
}
p = data+5;
@@ -655,8 +655,14 @@
/*
* Calculate required delta-offset to keep TCP happy
*/
- ftp->delta += strlen(buf) - (data-p);
- if (ftp->delta==0)
+
+ diff = strlen(buf) - (data-p);
+
+ /*
+ * No shift.
+ */
+
+ if (diff==0)
{
/*
* simple case, just replace the old PORT cmd
@@ -667,6 +673,18 @@
}
/*
+ * If the PORT command we have fiddled is the first, or is a
+ * resend don't do the delta shift again. Doesn't work for
+ * pathological cases, but we would need a history for that.
+ * Also fails if you send 2^31 bytes of data down the link
+ * after the first port command.
+ *
+ * FIXME: use ftp->init_seq_valid - 0 is a valid sequence.
+ */
+
+ if(!ftp->init_seq || after(ftp->init_seq,th->seq))
+ ftp->delta+=diff;
+ /*
* Sizes differ, make a copy
*/
printk("MASQUERADE: resizing needed for %d bytes (%ld)\n",ftp->delta, skb->len);
@@ -681,7 +699,9 @@
skb2->free = skb->free;
skb_reserve(skb2,MAX_HEADER);
skb_put(skb2,skb->len + ftp->delta);
- skb2->h.raw = &skb2->data[skb->h.raw - skb->data];
+/* skb2->h.raw = &skb2->data[skb->h.raw - skb->data];*/
+ skb2->h.raw = skb2->data + (skb->h.raw - skb->data);
+ iph=skb2->h.iph;
/*
* Copy the packet data into the new buffer.
@@ -690,7 +710,7 @@
memcpy(skb2->data, skb->data, (p - (char *)skb->data));
memcpy(&skb2->data[(p - (char *)skb->data)], buf, strlen(buf));
memcpy(&skb2->data[(p - (char *)skb->data) + strlen(buf)], data,
- skb->len - ((char *)skb->h.raw - data));
+ skb->len - (data-(char *)skb->data));
/*
* Problem, how to replace the new skb with old one,
@@ -798,6 +818,7 @@
*skb_ptr = skb;
iph = skb->h.iph;
portptr = (unsigned short *)&(((char *)iph)[iph->ihl*4]);
+ size = skb->len - ((unsigned char *)portptr-skb->h.raw);
}
th = (struct tcphdr *)portptr;
--- net/core/iovec.c.old Sat Sep 2 21:45:59 1995
+++ net/core/iovec.c Mon Sep 4 23:08:59 1995
@@ -47,12 +50,16 @@
for(ct=0;ct<m->msg_iovlen;ct++)
{
- err=verify_area(mode, m->msg_iov[ct].iov_base, m->msg_iov[ct].iov_len);
+ err=verify_area(VERIFY_READ, &m->msg_iov[ct], sizeof(struct iovec));
if(err)
return err;
- len+=m->msg_iov[ct].iov_len;
+ memcpy_fromfs(&iov[ct], &m->msg_iov[ct], sizeof(struct iovec));
+ err=verify_area(mode, iov[ct].iov_base, iov[ct].iov_len);
+ if(err)
+ return err;
+ len+=iov[ct].iov_len;
}
-
+ m->msg_iov=&iov[0];
return len;
}
