Re: [Crash-utility] [PATCH] Fix for "net -s" option to show an IPv6 address

On 2023/02/14 18:20, lijiang wrote: >>> On Tue, Feb 14, 2023 at 3:46 PM HAGIO KAZUHITO(萩尾 一仁) < k-hagio-ab(a)nec.com <mailto:k-hagio-ab@nec.com>> wrote: >>> >>> On 2023/02/09 21:15, Lianbo Jiang wrote: >>> > Currently, the "net -s" command fails to show an IPv6 address. For >>> > example: >>> > >>> > crash> net -s >>> > PID: 305524 TASK: ffff9bc449895580 CPU: 6 COMMAND: "sshd" >>> > FD SOCKET SOCK FAMILY:TYPE SOURCE-PORT DESTINATION-PORT >>> > 3 ffff9bc446e9a680 ffff9bc4455b5940 UNIX:DGRAM >>> > 4 ffff9bc446e9c600 ffff9bc3b2b24e00 INET6:STREAM >>> > >>> > With the patch: >>> > crash> net -s >>> > PID: 305524 TASK: ffff9bc449895580 CPU: 6 COMMAND: "sshd" >>> > FD SOCKET SOCK FAMILY:TYPE SOURCE-PORT DESTINATION-PORT >>> > 3 ffff9bc446e9a680 ffff9bc4455b5940 UNIX:DGRAM >>> > 4 ffff9bc446e9c600 ffff9bc3b2b24e00 INET6:STREAM xxxx:xx:x:xxxx:xxxx:xxxx:xxxx:xxxx-22 yyyy:yy:y:yyyy:yyyy:yyyy:yyyy:yyyy-44870 >>> > >>> > Let's support displaying the IPv6 address and port in the SOURCE-PORT >>> > and DESTINATION-PORT colums. >>> > >>> > Reported-by: Buland Kumar Singh <bsingh(a)redhat.com <mailto: bsingh(a)redhat.com&gt;&gt; >>> > Signed-off-by: Lianbo Jiang <lijiang(a)redhat.com <mailto: lijiang(a)redhat.com&gt;&gt; >>> >>> Good catch, I didn't know "net -s" could print IPv6 addresses... >>> >>> Is this the corresponding kernel patch? >>> >>> Yes. Actually there are two related kernel commits: >>> [1] 1da177e4c3f4 ("Linux-2.6.12-rc2") This looks the initial patch in the repository?

>>> [2] efe4208f47f9 ("ipv6: make lookups simpler and faster") v3.13-rc1 >>> >>> Can you help to add this to the patch log? I forgot to add them. Yes, added this.

>>> >>> commit efe4208f47f907b86f528788da711e8ab9dea44d >>> Author: Eric Dumazet <edumazet(a)google.com <mailto: edumazet(a)google.com&gt;&gt; >>> Date: Thu Oct 3 15:42:29 2013 -0700 >>> >>> ipv6: make lookups simpler and faster >>> >>> > --- >>> > defs.h | 3 +++ >>> > net.c | 40 ++++++++++++++++++++++++++++------------ >>> > symbols.c | 6 ++++++ >>> > 3 files changed, 37 insertions(+), 12 deletions(-) >>> > >>> > diff --git a/defs.h b/defs.h >>> > index 33a823b7b67c..db20056dc3ed 100644 >>> > --- a/defs.h >>> > +++ b/defs.h >>> > @@ -2204,6 +2204,9 @@ struct offset_table { /* stash of commonly-used offsets */ >>> > long maple_range_64_slot; >>> > long maple_metadata_end; >>> > long maple_metadata_gap; >>> > + long sock_sk_common; >>> > + long sock_common_skc_v6_daddr; >>> > + long sock_common_skc_v6_rcv_saddr; >>> > }; >>> > >>> > struct size_table { /* stash of commonly-used sizes */ >>> > diff --git a/net.c b/net.c >>> > index 7c9c8bd9c98d..7af299d0774d 100644 >>> > --- a/net.c >>> > +++ b/net.c >>> > @@ -198,6 +198,9 @@ net_init(void) >>> > */ >>> > MEMBER_OFFSET_INIT(sock_common_skc_family, >>> > "sock_common", "skc_family"); >>> > + MEMBER_OFFSET_INIT(sock_sk_common, "sock", "__sk_common"); >>> > + MEMBER_OFFSET_INIT(sock_common_skc_v6_daddr, "sock_common", "skc_v6_daddr"); >>> > + MEMBER_OFFSET_INIT(sock_common_skc_v6_rcv_saddr, "sock_common", "skc_v6_rcv_saddr"); >>> > MEMBER_OFFSET_INIT(sock_sk_type, "sock", "sk_type"); >>> > /* >>> > * struct inet_sock { >>> > @@ -1104,19 +1107,32 @@ get_sock_info(ulong sock, char *buf) >>> > break; >>> > >>> > case SOCK_V2: >>> > - if (INVALID_MEMBER(ipv6_pinfo_rcv_saddr) || >>> > - INVALID_MEMBER(ipv6_pinfo_daddr)) >>> > - break; >>> > - >>> > - ipv6_rcv_saddr = ipv6_pinfo + OFFSET(ipv6_pinfo_rcv_saddr); >>> > - ipv6_daddr = ipv6_pinfo + OFFSET(ipv6_pinfo_daddr); >>> > - >>> > - if (!readmem(ipv6_rcv_saddr, KVADDR, u6_addr16_src, SIZE(in6_addr), >>> > - "ipv6_rcv_saddr buffer", QUIET|RETURN_ON_ERROR)) >>> > - break; >>> > - if (!readmem(ipv6_daddr, KVADDR, u6_addr16_dest, SIZE(in6_addr), >>> > - "ipv6_daddr buffer", QUIET|RETURN_ON_ERROR)) >>> > + if (VALID_MEMBER(ipv6_pinfo_rcv_saddr) && >>> > + VALID_MEMBER(ipv6_pinfo_daddr)) { >>> > + ipv6_rcv_saddr = ipv6_pinfo + OFFSET(ipv6_pinfo_rcv_saddr); >>> > + ipv6_daddr = ipv6_pinfo + OFFSET(ipv6_pinfo_daddr); >>> > + >>> > + if (!readmem(ipv6_rcv_saddr, KVADDR, u6_addr16_src, SIZE(in6_addr), >>> > + "ipv6_rcv_saddr buffer", QUIET|RETURN_ON_ERROR)) >>> > + break; >>> > + if (!readmem(ipv6_daddr, KVADDR, u6_addr16_dest, SIZE(in6_addr), >>> > + "ipv6_daddr buffer", QUIET|RETURN_ON_ERROR)) >>> > + break; I moved these two readmem()s and the following two readmem()s out of the if block, because they are the same.

>>> > + } else if (VALID_MEMBER(sock_sk_common) && VALID_MEMBER(sock_common_skc_v6_daddr) && >>> > + VALID_MEMBER(sock_common_skc_v6_rcv_saddr)) { >>> > + ipv6_rcv_saddr = sock + OFFSET(sock_sk_common) + OFFSET(sock_common_skc_v6_rcv_saddr); >>> > + ipv6_daddr = sock + OFFSET(sock_sk_common) + OFFSET(sock_common_skc_v6_daddr); >>> > + >>> > + if (!readmem(ipv6_rcv_saddr, KVADDR, u6_addr16_src, SIZE(in6_addr), >>> > + "ipv6_rcv_saddr buffer", QUIET|RETURN_ON_ERROR)) >>> > + break; >>> > + if (!readmem(ipv6_daddr, KVADDR, u6_addr16_dest, SIZE(in6_addr), >>> > + "ipv6_daddr buffer", QUIET|RETURN_ON_ERROR)) >>> > + break; >>> > + } else { >>> > + error(INFO, "Invalid member...\n"); >>> >>> This message is unusual and vague, and the output looks not good: >>> (I forced to print this.) >>> >>> crash> net -s 1 >>> PID: 1 TASK: ffff9c6b8159c8c0 CPU: 11 COMMAND: "systemd" >>> FD SOCKET SOCK FAMILY:TYPE SOURCE-PORT DESTINATION-PORT >>> ... >>> 41 ffff9c79974b70c0 ffff9c79afcfb700 INET:DGRAM 0.0.0.0-111 0.0.0.0-0 >>> 42 ffff9c79974b1e40 ffff9c7a6f4347c0 net: Invalid member... >>> INET6:STREAM >>> 43 ffff9c79974b1340 ffff9c7a6f43e780 net: Invalid member... >>> INET6:DGRAM >>> 44 ffff9c79974b3180 ffff9c767da66780 UNIX:SEQPACKET >>> ... >>> >>> How about this? >>> >>> >>> Looks good. >>> >>> } else { >>> - error(INFO, "Invalid member...\n"); >>> + sprintf(&buf[strlen(buf)], "%s", "(cannot get IPv6 addresses)"); >>> break; >>> >>> 41 ffff9c79974b70c0 ffff9c79afcfb700 INET:DGRAM 0.0.0.0-111 0.0.0.0-0 >>> 42 ffff9c79974b1e40 ffff9c7a6f4347c0 INET6:STREAM (cannot get IPv6 addresses) >>> 43 ffff9c79974b1340 ffff9c7a6f43e780 INET6:DGRAM (cannot get IPv6 addresses) >>> 44 ffff9c79974b3180 ffff9c767da66780 UNIX:SEQPACKET >>> >>> Otherwise, looks good, although I would like to tweak some indents >>> a bit. >>> >>> >>> The Ipv6 address is a very long string, I tried adjusting the indent, but it still doesn't look good. sorry, I meant "code indents", changed some. No problem.

>> Thanks. >>> Lianbo >>> >>> >>> Thanks, >>> Kazu >>> >>> > break; >>> > + } >>> > >>> > sprintf(&buf[strlen(buf)], "%*s ", BITS32() ? 22 : 12, >>> > dump_in6_addr_port(u6_addr16_src, sport, buf2, &len)); >>> > diff --git a/symbols.c b/symbols.c >>> > index e38df8aad0f5..d622de722ebd 100644 >>> > --- a/symbols.c >>> > +++ b/symbols.c >>> > @@ -9820,6 +9820,12 @@ dump_offset_table(char *spec, ulong makestruct) >>> > OFFSET(sock_sk_type)); >>> > fprintf(fp, " sock_common_skc_family: %ld\n", >>> > OFFSET(sock_common_skc_family)); >>> > + fprintf(fp, " sock_sk_common: %ld\n", >>> > + OFFSET(sock_sk_common)); >>> > + fprintf(fp, " sock_common_skc_v6_daddr: %ld\n", >>> > + OFFSET(sock_common_skc_v6_daddr)); >>> > + fprintf(fp, " sock_common_skc_v6_rcv_saddr: %ld\n", >>> > + OFFSET(sock_common_skc_v6_rcv_saddr)); Changed the order, because it's better to gather the same struct members together.

https://github.com/crash-utility/crash/commit/c64a827e0bcab15e86f8fbacec1... Thanks! Kazu