Hi Lianbo,
thank you for the update.
For a few details..
On 2023/03/03 16:23, Lianbo Jiang wrote:
> Currently, the "net" command displays only the IPv4 address of a network
> interface, it doesn't support outputting IPv6 address yet. For example:
>
> Without the patch:
> crash> net
> NET_DEVICE NAME IP ADDRESS(ES)
> ffff8d01b1205000 lo 127.0.0.1
> ffff8d0087e40000 eno1 192.168.122.2
>
> With the patch:
> crash> net
> NET_DEVICE NAME IP ADDRESS(ES)
> ffff8d01b1205000 lo 127.0.0.1, ::1
> ffff8d0087e40000 eno1 192.168.122.2, xxxx:xx:x:xxxx:xxxx:xxx:xxxx:xxxx, yyyy::yyyy:yyy:yyyy:yyyy
>
> Related kernel commit:
> 502a2ffd7376 ("ipv6: convert idev_list to list macros")
>
> Reported-by: Buland Kumar Singh <bsingh@redhat.com>
> Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
> ---
> defs.h | 6 +++
> net.c | 109 +++++++++++++++++++++++++++++++++++++++++++++++++-----
> symbols.c | 6 +++
> 3 files changed, 112 insertions(+), 9 deletions(-)
>
> diff --git a/defs.h b/defs.h
> index e76af3c78b69..1f2cf6e0ce01 100644
> --- a/defs.h
> +++ b/defs.h
> @@ -2208,6 +2208,12 @@ struct offset_table { /* stash of commonly-used offsets */
> long sock_common_skc_v6_daddr;
> long sock_common_skc_v6_rcv_saddr;
> long inactive_task_frame_bp;
> + long net_device_ip6_ptr;
> + long inet6_dev_addr_list;
> + long inet6_ifaddr_addr;
> + long inet6_ifaddr_if_list;
> + long inet6_ifaddr_if_next;
> + long in6_addr_in6_u;
> };
>
> struct size_table { /* stash of commonly-used sizes */
> diff --git a/net.c b/net.c
> index aa445ab7ee13..6bca2a5d0098 100644
> --- a/net.c
> +++ b/net.c
> @@ -71,6 +71,7 @@ static void print_neighbour_q(ulong, int);
> static void get_netdev_info(ulong, struct devinfo *);
> static void get_device_name(ulong, char *);
> static long get_device_address(ulong, char **, long);
> +static void get_device_ip6_address(ulong, char **, long);
> static void get_sock_info(ulong, char *);
> static void dump_arp(void);
> static void arp_state_to_flags(unsigned char);
> @@ -114,6 +115,13 @@ net_init(void)
> net->dev_ip_ptr = MEMBER_OFFSET_INIT(net_device_ip_ptr,
> "net_device", "ip_ptr");
> MEMBER_OFFSET_INIT(net_device_dev_list, "net_device", "dev_list");
> + MEMBER_OFFSET_INIT(net_device_ip6_ptr, "net_device", "ip6_ptr");
> + MEMBER_OFFSET_INIT(inet6_dev_addr_list, "inet6_dev", "addr_list");
> + MEMBER_OFFSET_INIT(inet6_ifaddr_addr, "inet6_ifaddr", "addr");
> + MEMBER_OFFSET_INIT(inet6_ifaddr_if_list, "inet6_ifaddr", "if_list");
> + MEMBER_OFFSET_INIT(inet6_ifaddr_if_next, "inet6_ifaddr", "if_next");
> + MEMBER_OFFSET_INIT(in6_addr_in6_u, "in6_addr", "in6_u");
> +
> MEMBER_OFFSET_INIT(net_dev_base_head, "net", "dev_base_head");
> ARRAY_LENGTH_INIT(net->net_device_name_index,
> net_device_name, "net_device.name", NULL, sizeof(char));
> @@ -466,7 +474,7 @@ show_net_devices(ulong task)
> buf = GETBUF(buflen);
> flen = MAX(VADDR_PRLEN, strlen(net->netdevice));
>
> - fprintf(fp, "%s NAME IP ADDRESS(ES)\n",
> + fprintf(fp, "%s NAME IP ADDRESS(ES)\n",
> mkstring(upper_case(net->netdevice, buf),
> flen, CENTER|LJUST, NULL));
>
> @@ -475,9 +483,10 @@ show_net_devices(ulong task)
> mkstring(buf, flen, CENTER|RJUST|LONG_HEX, MKSTR(next)));
>
> get_device_name(next, buf);
> - fprintf(fp, "%-6s ", buf);
> + fprintf(fp, "%-10s ", buf);
>
> - buflen = get_device_address(next, &buf, buflen);
> + get_device_address(next, &buf, buflen);
> + get_device_ip6_address(next, &buf, buflen);
> fprintf(fp, "%s\n", buf);
>
> readmem(next+net->dev_next, KVADDR, &next,
> @@ -503,7 +512,7 @@ show_net_devices_v2(ulong task)
> buf = GETBUF(buflen);
> flen = MAX(VADDR_PRLEN, strlen(net->netdevice));
>
> - fprintf(fp, "%s NAME IP ADDRESS(ES)\n",
> + fprintf(fp, "%s NAME IP ADDRESS(ES)\n",
> mkstring(upper_case(net->netdevice, buf),
> flen, CENTER|LJUST, NULL));
>
> @@ -528,9 +537,10 @@ show_net_devices_v2(ulong task)
> MKSTR(ld->list_ptr[i])));
>
> get_device_name(ld->list_ptr[i], buf);
> - fprintf(fp, "%-6s ", buf);
> + fprintf(fp, "%-10s ", buf);
>
> - buflen = get_device_address(ld->list_ptr[i], &buf, buflen);
> + get_device_address(ld->list_ptr[i], &buf, buflen);
> + get_device_ip6_address(ld->list_ptr[i], &buf, buflen);
> fprintf(fp, "%s\n", buf);
> }
>
> @@ -556,7 +566,7 @@ show_net_devices_v3(ulong task)
> buf = GETBUF(buflen);
> flen = MAX(VADDR_PRLEN, strlen(net->netdevice));
>
> - fprintf(fp, "%s NAME IP ADDRESS(ES)\n",
> + fprintf(fp, "%s NAME IP ADDRESS(ES)\n",
> mkstring(upper_case(net->netdevice, buf),
> flen, CENTER|LJUST, NULL));
>
> @@ -591,9 +601,10 @@ show_net_devices_v3(ulong task)
> MKSTR(ld->list_ptr[i])));
>
> get_device_name(ld->list_ptr[i], buf);
> - fprintf(fp, "%-6s ", buf);
> + fprintf(fp, "%-10s ", buf);
>
> - buflen = get_device_address(ld->list_ptr[i], &buf, buflen);
> + get_device_address(ld->list_ptr[i], &buf, buflen);
> + get_device_ip6_address(ld->list_ptr[i], &buf, buflen);
> fprintf(fp, "%s\n", buf);
> }
>
> @@ -925,6 +936,86 @@ get_device_address(ulong devaddr, char **bufp, long buflen)
> return buflen;
> }
>
> +static void
> +get_device_ip6_address(ulong devaddr, char **bufp, long buflen)
> +{
> + ulong ip6_ptr = 0, pos = 0, bufsize = buflen, addr = 0;
> + struct in6_addr ip6_addr;
> + char *buf;
> + char str[INET6_ADDRSTRLEN + 1] = {0};
> + char buffer[INET6_ADDRSTRLEN + 4] = {0};
What are the +1 and +4 for?
I noticed that the size of INET6_ADDRSTRLEN is 48 in kernel code as below:
--- a/include/linux/inet.h
+++ b/include/linux/inet.h
+/*
+ * These mimic similar macros defined in user-space for inet_ntop(3).
+ * See /usr/include/netinet/in.h .
+ */
+#define INET_ADDRSTRLEN (16)
+#define INET6_ADDRSTRLEN (48)
And, the size of INET6_ADDRSTRLEN is 46 in my machine as below:
# cat /usr/include/netinet/in.h |grep INET6_ADDRSTRLEN
#define INET6_ADDRSTRLEN 46
The rfc2460 said that the IPv6 increases the IP address size from 32 bits to 128 bits.
crash> struct in6_addr
struct in6_addr {
union {
__u8 u6_addr8[16];
__be16 u6_addr16[8];
__be32 u6_addr32[4];
} in6_u;
}
SIZE: 16
Given that, maybe they should be defined like this?
+ char str[INET6_ADDRSTRLEN + 2] = {0};
+ char buffer[INET6_ADDRSTRLEN + 2 + 2] = {0};
Not sure what's the best way for this case.
Looking at the example in the man page of inet_pton(3), INET6_ADDRSTRLEN
seems enough for the str and contains a null char. The buffer can have
a comma and a space (", ") so +2 is enough? i.e.
char str[INET6_ADDRSTRLEN] = {0};
char buffer[INET6_ADDRSTRLEN + 2] = {0};
> + uint len = 0;
> +
> + buf = *bufp;
> + pos = strlen(buf);
Ah nicely done :)
> +
> + readmem(devaddr + OFFSET(net_device_ip6_ptr), KVADDR,
> + &ip6_ptr, sizeof(ulong), "ip6_ptr", FAULT_ON_ERROR);
> +
> + if (!ip6_ptr)
> + return;
> +
> + if (VALID_MEMBER(inet6_ifaddr_if_list)) {
> + struct list_data list_data, *ld;
> + ulong cnt = 0, i;
> +
> + ld = &list_data;
> + BZERO(ld, sizeof(struct list_data));
> + ld->flags |= LIST_ALLOCATE;
> + ld->start = ip6_ptr + OFFSET(inet6_dev_addr_list);
> + cnt = do_list(ld);
> +
> + for (i = 1; i < cnt; i++) {
> +
> + addr = ld->list_ptr[i] + OFFSET(inet6_ifaddr_addr);
> + addr -= OFFSET(inet6_ifaddr_if_list);
The above code is easy to understand, because it actually imitates the container_of().
But if you would like to have the same style as show_net_devices_v2() and show_net_devices_v3(), that's also fine to me.
This line can be removed with ld->list_head_offset parameter?
i.e.
ld->start = ip6_ptr + OFFSET(inet6_dev_addr_list);
+ ld->list_head_offset = OFFSET(inet6_ifaddr_if_list);
cnt = do_list(ld);
> + readmem(addr + OFFSET(in6_addr_in6_u), KVADDR, &ip6_addr,
> + sizeof(struct in6_addr), "in6_addr.in6_u", FAULT_ON_ERROR);
> +
> + inet_ntop(AF_INET6, (void*)&ip6_addr, str, INET6_ADDRSTRLEN);
> + sprintf(buffer, "%s%s", pos ? ", " : "", str);
> + len = strlen(buffer);
> + if (pos + len >= bufsize) {
> + RESIZEBUF(*bufp, bufsize, bufsize + buflen);
> + buf = *bufp;
> + BZERO(buf + bufsize, buflen);
> + bufsize += buflen;
> + }
> + BCOPY(buffer, &buf[pos], len);
> + pos += len;
> + }
> +
> + FREEBUF(ld->list_ptr);
> + return;
> + }
> +
> + /*
> + * 502a2ffd7376 ("ipv6: convert idev_list to list macros")
> + * v2.6.35-rc1~473^2~733
> + */
This should be moved before the if block above?
Yes, you are right. I forgot to move it there.
Thanks.
Lianbo
> + readmem(ip6_ptr + OFFSET(inet6_dev_addr_list), KVADDR,
> + &addr, sizeof(void *), "inet6_dev.addr_list", FAULT_ON_ERROR);
> +
> + while (addr) {
> + readmem(addr + OFFSET(in6_addr_in6_u), KVADDR, &ip6_addr,
> + sizeof(struct in6_addr), "in6_addr.in6_u", FAULT_ON_ERROR);
> + inet_ntop(AF_INET6, (void*)&ip6_addr, str, INET6_ADDRSTRLEN);
> + sprintf(buffer, "%s%s", pos ? ", " : "", str);
> + len = strlen(buffer);
> +
> + if (pos + len >= bufsize) {
> + RESIZEBUF(*bufp, bufsize, bufsize + buflen);
> + buf = *bufp;
> + BZERO(buf + bufsize, buflen);
> + bufsize += buflen;
> + }
> + BCOPY(buffer, &buf[pos], len);
> + pos += len;
> + readmem(addr + OFFSET(inet6_ifaddr_if_next), KVADDR, &addr,
> + sizeof(void *), "inet6_ifaddr.if_next", FAULT_ON_ERROR);
> + }
> +}
> +
> /*
> * Get the family, type, local and destination address/port pairs.
> */
> diff --git a/symbols.c b/symbols.c
> index a974fc9141a0..3efcdddfcadb 100644
> --- a/symbols.c
> +++ b/symbols.c
> @@ -9787,6 +9787,7 @@ dump_offset_table(char *spec, ulong makestruct)
> OFFSET(net_device_addr_len));
> fprintf(fp, " net_device_ip_ptr: %ld\n",
> OFFSET(net_device_ip_ptr));
> + fprintf(fp, " net_device_ip6_ptr: %ld\n", OFFSET(net_device_ip6_ptr));
> fprintf(fp, " net_device_dev_list: %ld\n",
> OFFSET(net_device_dev_list));
> fprintf(fp, " net_dev_base_head: %ld\n",
> @@ -9839,6 +9840,11 @@ dump_offset_table(char *spec, ulong makestruct)
> fprintf(fp, " inet_opt_num: %ld\n",
> OFFSET(inet_opt_num));
>
> + fprintf(fp, " inet6_dev_addr_list: %ld\n", OFFSET(inet6_dev_addr_list));
> + fprintf(fp, " inet6_ifaddr_addr: %ld\n", OFFSET(inet6_ifaddr_addr));
> + fprintf(fp, " inet6_ifaddr_if_list: %ld\n", OFFSET(inet6_ifaddr_if_list));
> + fprintf(fp, " inet6_ifaddr_if_next: %ld\n", OFFSET(inet6_ifaddr_if_next));
> + fprintf(fp, " in6_addr_in6_u: %ld\n", OFFSET(in6_addr_in6_u));
> fprintf(fp, " ipv6_pinfo_rcv_saddr: %ld\n",
> OFFSET(ipv6_pinfo_rcv_saddr));
> fprintf(fp, " ipv6_pinfo_daddr: %ld\n",
Thanks, good!
Kazu