Link time problems with libipq example code

DISCUSSION Craig Davison 3 participants 5 messages Dec 20, 2002 – Dec 23, 2002

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Craig Davison

author

2002-12-20 22:44 UTC #0 lore raw

Hello,
I've been trying to compile the libipq example code in the libipq man page.

My kernel is 2.4.18, distributed by RedHat as 2.4.18-14. I made a symlink to the kernel source at /usr/src/linux. I built ipchains 1.2.7a as follows:
make
su
make install-devel

I copied the code from the man page into a file called ipqtst.c and compiled:
gcc -I/usr/local/include -L/usr/local/lib -lipq -o ipqtst ipqtst.c /tmp/ccGDqSOi.o: In function `die':
/tmp/ccGDqSOi.o(.text+0xf): undefined reference to ipq_perror' /tmp/ccGDqSOi.o(.text+0x1d): undefined reference to ipq_destroy_handle' /tmp/ccGDqSOi.o: In function `main':
/tmp/ccGDqSOi.o(.text+0x49): undefined reference to ipq_create_handle' /tmp/ccGDqSOi.o(.text+0x81): undefined reference to ipq_set_mode' /tmp/ccGDqSOi.o(.text+0xb8): undefined reference to ipq_read' /tmp/ccGDqSOi.o(.text+0xe4): undefined reference to ipq_message_type' /tmp/ccGDqSOi.o(.text+0x116): undefined reference to ipq_get_msgerr' /tmp/ccGDqSOi.o(.text+0x141): undefined reference to ipq_get_packet' /tmp/ccGDqSOi.o(.text+0x166): undefined reference to `ipq_set_verdict'
collect2: ld returned 1 exit status

I get the same errors when I compile statically:
gcc -static -I/usr/local/include -L/usr/local/lib -lipq -o ipqtst ipqtst.c

Is libipq not the right thing to link against? Am I doing something else wrong (did I build ipchains incorrectly?)

Signature · 3 lines

Craig Davison
Symantec Corporation
+1 (403) 213-3939 ext. 228

Craig Davison

author

2002-12-20 23:01 UTC #1 lore raw

Here's the output from nm:
nm /usr/local/lib/libipq.a

libipq.o:
U bind
U close
U __errno_location
U fprintf
U fputc
U fputs
U free
U fwrite
U getpid
00000224 T ipq_create_handle
000004a4 T ipq_ctl
00000334 T ipq_destroy_handle
00000000 D ipq_errmap
00000088 d ipq_errno
000004b0 T ipq_errstr
000003c4 T ipq_get_msgerr
000003d4 T ipq_get_packet
000003b8 T ipq_message_type
00000060 t ipq_netlink_recvfrom
00000034 t ipq_netlink_sendmsg
00000000 t ipq_netlink_sendto
000004c4 T ipq_perror
000003ac T ipq_read
0000035c T ipq_set_mode
000003e0 T ipq_set_verdict
00000208 t ipq_strerror
U malloc
U recvfrom
U select
U sendmsg
U sendto
U socket
U stderr
U strerror

Quoted 1 line · Craig Davison

I've been trying to compile the libipq example code in the libipq man page.

Signature · 3 lines

Craig Davison
Symantec Corporation
+1 (403) 213-3939 ext. 228

Narendra Prabhu. B

2002-12-21 05:29 UTC #2 lore raw

In reply to Craig Davison

Hi,

Yes, even I have come across such problems.... I just complied it using the following command.

$gcc -I/usr/local/include -L/usr/local/lib -o ipqtst ipqtst.c -lipq

Just notice that I have put "-lipq" in the end... Well, I have not been able to reason, why it works this way. Its probably the gcc issue.

Hope this helps.

Bye,
Narendra.

Quoted 27 lines · Craig Davison

Hello,
I've been trying to compile the libipq example code in the libipq man page.
My kernel is 2.4.18, distributed by RedHat as 2.4.18-14. I made a symlink to the kernel source at /usr/src/linux. I built ipchains 1.2.7a as follows:
make
su
make install-devel
I copied the code from the man page into a file called ipqtst.c and compiled:
gcc -I/usr/local/include -L/usr/local/lib -lipq -o ipqtst ipqtst.c /tmp/ccGDqSOi.o: In function `die':
/tmp/ccGDqSOi.o(.text+0xf): undefined reference to ipq_perror' /tmp/ccGDqSOi.o(.text+0x1d): undefined reference to ipq_destroy_handle' /tmp/ccGDqSOi.o: In function `main':
/tmp/ccGDqSOi.o(.text+0x49): undefined reference to ipq_create_handle' /tmp/ccGDqSOi.o(.text+0x81): undefined reference to ipq_set_mode' /tmp/ccGDqSOi.o(.text+0xb8): undefined reference to ipq_read' /tmp/ccGDqSOi.o(.text+0xe4): undefined reference to ipq_message_type' /tmp/ccGDqSOi.o(.text+0x116): undefined reference to ipq_get_msgerr' /tmp/ccGDqSOi.o(.text+0x141): undefined reference to ipq_get_packet' /tmp/ccGDqSOi.o(.text+0x166): undefined reference to `ipq_set_verdict'
collect2: ld returned 1 exit status
I get the same errors when I compile statically:
gcc -static -I/usr/local/include -L/usr/local/lib -lipq -o ipqtst ipqtst.c

Quoted 8 lines

Is libipq not the right thing to link against? Am I doing something else wrong (did I build ipchains incorrectly?)
--
Craig Davison
Symantec Corporation
+1 (403) 213-3939 ext. 228

In the middle of difficulty..... lies Opportunity. (Albert Einstein)
--------------------------------------------------------------------
Narendra Prabhu. B Free Software at its product-ive best.
DeepRoot Linux http://www.deeproot.co.in
---- Server Appliances ----
---- Linux Support and Services ----
-------------------------------------------------------------------

Craig Davison

author

2002-12-23 18:07 UTC #3 lore raw

That did it - thanks!

Signature · 3 lines

Craig Davison
Symantec Corporation
+1 (403) 213-3939 ext. 228

Quoted 9 lines · Narendra Prabhu. B

Hi,
Yes, even I have come across such problems.... I just complied it using the following command.
$gcc -I/usr/local/include -L/usr/local/lib -o ipqtst ipqtst.c -lipq
Just notice that I have put "-lipq" in the end... Well, I have not been able to reason, why it works this way. Its probably the gcc issue.

Ranjeet Shetye

2002-12-23 19:05 UTC #4 lore raw

In reply to Narendra Prabhu. B

Hi Narendra,

The behaviour you are observing is related to the way gcc resolves sumbols while compiling code.

http://webclub.kcom.ne.jp/ma/colinp/win32/tools/link.html

"
gcc checks libraries in the order they appear, and it will only resolve references to symbols in libraries earlier on the command line if the object containing the symbol definition was already included for some other reason. Thus if foo.o uses a function in libstuff.a the following command line will fail:

gcc -o foobar.exe -lstuff foo.o bar.o
"

Which is what you guys are running into.

Ranjeet Shetye
Senior Software Engineer
Zultys Technologies
771 Vaqueros Avenue
Sunnyvale CA 94085
USA
[email protected]
http://www.zultys.com/

Quoted 84 lines

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Narendra Prabhu. B
Sent: Friday, December 20, 2002 9:30 PM
To: Craig Davison
Cc: [email protected]
Subject: Re: Link time problems with libipq example code
Hi,
Yes, even I have come across such problems.... I just complied it using the following command.
$gcc -I/usr/local/include -L/usr/local/lib -o ipqtst ipqtst.c -lipq
Just notice that I have put "-lipq" in the end... Well, I have not been able to reason, why it works this way. Its probably the gcc issue.
Hope this helps.
Bye,
Narendra.
Quoted 2 lines · Craig Davison
Hello,
I've been trying to compile the libipq example code in the
libipq man
Quoted 7 lines
page.
My kernel is 2.4.18, distributed by RedHat as 2.4.18-14. I made a symlink to the kernel source at /usr/src/linux. I built ipchains 1.2.7a as follows: make su
make install-devel
Quoted 6 lines
I copied the code from the man page into a file called ipqtst.c and
compiled: gcc -I/usr/local/include -L/usr/local/lib -lipq -o ipqtst ipqtst.c
/tmp/ccGDqSOi.o: In function `die':
/tmp/ccGDqSOi.o(.text+0xf): undefined reference to `ipq_perror' /tmp/ccGDqSOi.o(.text+0x1d): undefined reference to
`ipq_destroy_handle'
Quoted 2 lines
/tmp/ccGDqSOi.o: In function `main':
/tmp/ccGDqSOi.o(.text+0x49): undefined reference to
`ipq_create_handle'
Quoted 3 lines
/tmp/ccGDqSOi.o(.text+0x81): undefined reference to ipq_set_mode' /tmp/ccGDqSOi.o(.text+0xb8): undefined reference to ipq_read' /tmp/ccGDqSOi.o(.text+0xe4): undefined reference to
`ipq_message_type'
Quoted 1 line
/tmp/ccGDqSOi.o(.text+0x116): undefined reference to
`ipq_get_msgerr'
Quoted 1 line
/tmp/ccGDqSOi.o(.text+0x141): undefined reference to
`ipq_get_packet'
Quoted 1 line
/tmp/ccGDqSOi.o(.text+0x166): undefined reference to
`ipq_set_verdict'
Quoted 6 lines
collect2: ld returned 1 exit status
I get the same errors when I compile statically:
gcc -static -I/usr/local/include -L/usr/local/lib -lipq -o ipqtst ipqtst.c
Quoted 9 lines
Is libipq not the right thing to link against? Am I doing something else wrong (did I build ipchains incorrectly?)
--
Craig Davison
Symantec Corporation
+1 (403) 213-3939 ext. 228
In the middle of difficulty..... lies Opportunity. (Albert Einstein)
--------------------------------------------------------------------
Narendra Prabhu. B Free Software at its product-ive best.
DeepRoot Linux http://www.deeproot.co.in
---- Server Appliances ----
---- Linux Support and Services ----
-------------------------------------------------------------------