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@redhat.com>
> Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
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")
[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.
commit efe4208f47f907b86f528788da711e8ab9dea44d
Author: Eric Dumazet <edumazet@google.com>
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;
> + } 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.
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));
> fprintf(fp, " socket_alloc_vfs_inode: %ld\n",
> OFFSET(socket_alloc_vfs_inode));
> fprintf(fp, " inet_sock_inet: %ld\n",