Bug 24445
| Summary: | ipnat does not parse its file properly | ||
|---|---|---|---|
| Product: | Base System | Reporter: | hsw <hsw> |
| Component: | gnu | Assignee: | Darern Reed <darrenr> |
| Status: | Closed FIXED | ||
| Severity: | Affects Only Me | ||
| Priority: | Normal | ||
| Version: | 4.2-STABLE | ||
| Hardware: | Any | ||
| OS: | Any | ||
setting 'proto' to NULL did not work completely as there some protocols e.g pop3s that have no corresponding udp number Since I am only redirecting tcp add: proto = "tcp"; to start of natparse instead. In message <200101190336.f0J3aVe43887@w40.tucheng.generalresources.com>, Christopher Hall writes: > >>Number: 24445 >>Category: gnu >>Synopsis: ipnat does not parse its file properly >>Confidential: no >>Severity: serious >>Priority: high >>Responsible: freebsd-bugs >>State: open >>Quarter: >>Keywords: >>Date-Required: >>Class: sw-bug >>Submitter-Id: current-users >>Arrival-Date: Thu Jan 18 19:40:01 PST 2001 >>Closed-Date: >>Last-Modified: >>Originator: Christopher Hall >>Release: FreeBSD 4.2-STABLE i386 >>Organization: >>Environment: > > 4.2-STABLE FreeBSD 4.2-STABLE #0: Thu Jan 18 13:15:08 CST 2001 > >>Description: > > Using the following configuration file: > > map fxp1 192.168.1.250/16 -> 1.2.3.4/32 portmap tcp/udp 40000:60000 > map fxp1 192.168.1.250/16 -> 1.2.3.4/32 > ##rdr fxp0 192.168.1.250/32 port 80 -> 4.5.6.7 port 80 > rdr fxp0 192.168.1.250/32 port http -> 4.5.6.7 port http > rdr fxp0 192.168.1.250/32 port https -> 4.5.6.7 port https > > >Get errors like this > > 4: unknown service "http". > 4: syntax error in "rdr" > 5: unknown service "https". > 5: syntax error in "rdr" > > can stop error by: > a) remove the '##' in line 3 > b) comment out line 1 > c) move line 1 to end of file > > >The problem is caused by a global variable in the file common.c >its definition is: char *proto = NULL; > >the file natparse.c uses the routine "portnum" to convert the >string "http" to a number > >'proto' is now pointing at the position in the line buffer where >the string "tcp/udp" used to be from line 1 of config file. > >Therefore the variable 'proto' points at the ".7" of the ip number when >parsing line 4. > >Using numeric port number does not access the global 'proto' variable in >portnum and later in natparse sets 'proto' pointing to static string "tcp" >for parsing the remaining lines. > >Any line that contains a protocol will set the 'proto' variable for >the next line. If this line is longer the 'proto' variable will be >pointing at an invalid string. > > >>How-To-Repeat: > > ipnat -f ipnat.conf (see above for for config file contents) > >>Fix: > > Don't use global variables like this! > > Should eliminate the global proto variable and pass the protocol > as a parameter to portnum. It looks like proto variable > is only shared by natparse.c parse.c and common.c. > > As far as I can tell only the 'rdr' command is affected, because > the protocol specified on the end of the line so the 'proto' variable > gets set too late. > > In natparse.c the is a section to decode the protocol, this would > have to be move before the first portnum call. However the method > of parsing the command line by using "cpp++;" to bump the toke pointer. > The easiest would be to change the syntax of the "rdr" command > from: > rdr le0 203.1.2.3/32 port 80 -> 203.1.2.3,203.1.2.4 port 80 tcp > to: > rdr tcp le0 203.1.2.3/32 port 80 -> 203.1.2.3,203.1.2.4 port 80 > > > Temporary Fix: > > Assume the protocol will be tcp or udp and that the same number > applies to both. > > To do this, just add the following line to the start of the > function natparse in natparse.c: > > proto = NULL; > > > Any better ideas? > >>Release-Note: >>Audit-Trail: >>Unformatted: > > >To Unsubscribe: send mail to majordomo@FreeBSD.org >with "unsubscribe freebsd-bugs" in the body of the message > --- Christopher Hall <atheist@generalresources.com> Responsible Changed From-To: freebsd-bugs->darrenr darrenr is responsible for ipnat State Changed From-To: open->suspended next import of ipfilter will fix this problem State Changed From-To: suspended->closed FreeBSD 4.4 and -current with ipf version 3.4.20 does not have this problem. |
Using the following configuration file: map fxp1 192.168.1.250/16 -> 1.2.3.4/32 portmap tcp/udp 40000:60000 map fxp1 192.168.1.250/16 -> 1.2.3.4/32 ##rdr fxp0 192.168.1.250/32 port 80 -> 4.5.6.7 port 80 rdr fxp0 192.168.1.250/32 port http -> 4.5.6.7 port http rdr fxp0 192.168.1.250/32 port https -> 4.5.6.7 port https Get errors like this 4: unknown service "http". 4: syntax error in "rdr" 5: unknown service "https". 5: syntax error in "rdr" can stop error by: a) remove the '##' in line 3 b) comment out line 1 c) move line 1 to end of file The problem is caused by a global variable in the file common.c its definition is: char *proto = NULL; the file natparse.c uses the routine "portnum" to convert the string "http" to a number 'proto' is now pointing at the position in the line buffer where the string "tcp/udp" used to be from line 1 of config file. Therefore the variable 'proto' points at the ".7" of the ip number when parsing line 4. Using numeric port number does not access the global 'proto' variable in portnum and later in natparse sets 'proto' pointing to static string "tcp" for parsing the remaining lines. Any line that contains a protocol will set the 'proto' variable for the next line. If this line is longer the 'proto' variable will be pointing at an invalid string. Fix: Don't use global variables like this! Should eliminate the global proto variable and pass the protocol as a parameter to portnum. It looks like proto variable is only shared by natparse.c parse.c and common.c. As far as I can tell only the 'rdr' command is affected, because the protocol specified on the end of the line so the 'proto' variable gets set too late. In natparse.c the is a section to decode the protocol, this would have to be move before the first portnum call. However the method of parsing the command line by using "cpp++;" to bump the toke pointer. The easiest would be to change the syntax of the "rdr" command from: rdr le0 203.1.2.3/32 port 80 -> 203.1.2.3,203.1.2.4 port 80 tcp to: rdr tcp le0 203.1.2.3/32 port 80 -> 203.1.2.3,203.1.2.4 port 80 Temporary Fix: Assume the protocol will be tcp or udp and that the same number applies to both. To do this, just add the following line to the start of the function natparse in natparse.c: proto = NULL; Any better ideas? How-To-Repeat: ipnat -f ipnat.conf (see above for for config file contents)