Hello,

I have a customized Kamailio (kamailio 5.1.1 (x86_64/linux)), xHTTP_PROM https://www.kamailio.org/docs/modules/devel/modules/xhttp_prom.html was released in the 5.3.0 https://www.kamailio.org/w/kamailio-v5-3-0-release-notes/ version.

I'm trying to import the latest version of xhttp_prom to older Kamailio, but something goes wrong. This is simple config for test:

log_stderror=yes

listen=5060 debug=2 mpath="/home/devel/build_dir/build/lib64/kamailio/modules" loadmodule "tm.so" loadmodule "sl.so" loadmodule "xlog.so" loadmodule "pv.so"

disable_tcp=no tcp_accept_no_cl=yes loadmodule "xhttp.so" loadmodule "xhttp_prom.so" modparam("xhttp_prom", "xhttp_prom_stats", "all") route { sl_send_reply("200", "OK"); exit; } event_route[xhttp:request] { if (prom_check_uri()) { prom_dispatch(); } else { xhttp_reply("404", "Not Found", "text/plain", "Wrong URL $hu\n"); } }

then I send HTTP request $ curl http://localhost:5060/metrics but get error:

6(110968) CRITICAL: <core> [core/pass_fd.c:277]: receive_fd(): EOF on 11 0(110962) ALERT: <core> [main.c:746]: handle_sigs(): child process 110967 exited by a signal 11 0(110962) ALERT: <core> [main.c:749]: handle_sigs(): core was generated 0(110962) INFO: <core> [main.c:771]: handle_sigs(): terminating due to SIGCHLD

note: for http://localhost:5060/test request I get the expected message "Wrong URL /test".

Backtrace for killed process

(gdb) c Continuing. Program received signal SIGSEGV, Segmentation fault. 0x00007fefff3ff096 in atomic_cmpxchg_int (var=0x0, old=0, new_v=1) at ../../core/mem/../atomic/atomic_x86.h:224 224 ATOMIC_FUNC_CMPXCHG(cmpxchg, "cmpxchgl %2, %1", int , int) (gdb) bt #0 0x00007fefff3ff096 in atomic_cmpxchg_int (var=0x0, old=0, new_v=1) at ../../core/mem/../atomic/atomic_x86.h:224 #1 0x00007fefff3ff0e2 in futex_get (lock=0x0) at ../../core/mem/../futexlock.h:99 #2 0x00007fefff4130bf in prom_metric_list_print (ctx=0x7fefff628da0 <ctx>) at prom_metric.c:1319 #3 0x00007fefff416468 in prom_stats_get (ctx=0x7fefff628da0 <ctx>, stat=0x7fefff6281f0 <xhttp_prom_stats>) at prom.c:178 #4 0x00007fefff3d4d10 in prom_send (ctx=0x7fefff628da0 <ctx>) at xhttp_prom.c:361 #5 0x00007fefff3d5faf in ki_xhttp_prom_dispatch (msg=0x7ffecb730ee0) at xhttp_prom.c:418 #6 0x00007fefff3d5feb in w_prom_dispatch (msg=0x7ffecb730ee0) at xhttp_prom.c:428 #7 0x0000000000461dbe in do_action (h=0x7ffecb730e00, a=0x7ff0007c7b78, msg=0x7ffecb730ee0) at core/action.c:1067 #8 0x000000000046e571 in run_actions (h=0x7ffecb730e00, a=0x7ff0007c7b78, msg=0x7ffecb730ee0) at core/action.c:1565 #9 0x0000000000461d2d in do_action (h=0x7ffecb730e00, a=0x7ff0007ca628, msg=0x7ffecb730ee0) at core/action.c:1058 #10 0x000000000046e571 in run_actions (h=0x7ffecb730e00, a=0x7ff0007c76f8, msg=0x7ffecb730ee0) at core/action.c:1565 #11 0x00007fefff62f649 in xhttp_process_request (orig_msg=0x7ff0007ebbd8, new_buf=0x7ff0007cc280 "GET /metrics HTTP/1.1\r\nVia: SIP/2.0/TCP 127.0.0.1:37000\r\nUser-Agent: curl/7.29.0\r\nHost: localhost:5060\r\nAccept: */*\r\n\r\n", new_len=119) at xhttp_mod.c:298 #12 0x00007fefff630d78 in xhttp_handler (msg=0x7ff0007ebbd8) at xhttp_mod.c:385 #13 0x0000000000520141 in nonsip_msg_run_hooks (msg=0x7ff0007ebbd8) at core/nonsip_hooks.c:111 #14 0x000000000058cef1 in receive_msg (buf=0x7feffee65bb0 "GET /metrics HTTP/1.1\r\nUser-Agent: curl/7.29.0\r\nHost: localhost:5060\r\nAccept: */*\r\n\r\n", len=85, rcv_info=0x7feffee658d0) at core/receive.c:216 #15 0x000000000061233f in receive_tcp_msg (tcpbuf=0x7feffee65bb0 "GET /metrics HTTP/1.1\r\nUser-Agent: curl/7.29.0\r\nHost: localhost:5060\r\nAccept: */*\r\n\r\n", len=85, rcv_info=0x7feffee658d0, con=0x7feffee658b8) at core/tcp_read.c:1379 #16 0x000000000061479e in tcp_read_req (con=0x7feffee658b8, bytes_read=0x7ffecb731c7c, read_flags=0x7ffecb731c78) at core/tcp_read.c:1611 #17 0x00000000006174e9 in handle_io (fm=0x7ff0007d9720, events=1, idx=-1) at core/tcp_read.c:1785 #18 0x00000000006069b4 in io_wait_loop_epoll (h=0xaa76c0 <io_w>, t=2, repeat=0) at core/io_wait.h:1065 #19 0x00000000006194ff in tcp_receive_loop (unix_sock=14) at core/tcp_read.c:1955 #20 0x00000000004f1a43 in tcp_init_children () at core/tcp_main.c:4853 #21 0x0000000000423f99 in main_loop () at main.c:1716 #22 0x000000000042a5ee in main (argc=9, argv=0x7ffecb7323b8) at main.c:2646 (gdb) (gdb) p 'prom_metric.c'::prom_lock $4 = (gen_lock_t *) 0x0

If I understood correctly, the problem is in an uninitialized variable static gen_lock_t *prom_lock = NULL; /* Lock to protect Prometheus metrics. */

So, is it possible to import xHTTP_PROM to older Kamailio? I will be glad for any advice.

Thanks.