lsof/Handle-ffff-ffff-in-ipv6-addr-correctly.patch
2020-10-19 14:24:22 +08:00

85 lines
3.0 KiB
Diff

From e64dc10ea1d5be38681191d9f4d2aa9018ab59dc Mon Sep 17 00:00:00 2001
From: Masatake YAMATO <yamato@redhat.com>
Date: Sun, 4 Oct 2020 03:50:26 +0900
Subject: [PATCH] [linux] handle ffff:ffff in ipv6 addr correctly
Close #102
Close #109
The listen address and port of an AF_INET6 socket were not display if
the socket listened at an ipv6 address including ffff:ffff.
Here is a command session demonstrating the bug:
# ip -6 addr add abcd:ef10:ffff:ffff:ffff:ffff:ffff:ff62 dev lo
# nc -6 -l abcd:ef10:ffff:ffff:ffff:ffff:ffff:ff62 8888 &
[1] 6762
# ./lsof -p 6762 -a -d fd -P -n
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
nc 6762 yamato 0u CHR 136,6 0t0 9 /dev/pts/6
nc 6762 yamato 1u CHR 136,6 0t0 9 /dev/pts/6
nc 6762 yamato 2u CHR 136,6 0t0 9 /dev/pts/6
nc 6762 yamato 3u sock 0,9 0t0 5833594 protocol: TCPv6
The last line should be:
nc 6762 yamato 3u IPv6 5833594 0t0 TCP [abcd:ef10:ffff:ffff:ffff:ffff:ffff:ff62]:8888 (LISTEN)
The original code decoding an ipv6 address uses UINT32_MAX constant
incorrect way.
@zhrf2020 reported this bug in #102.
The test case is based on the report.
@zhrf2020 provided the initial version of fix, #109.
This change is based on the version.
---
dialects/linux/dsock.c | 33 ++++++++++++-
1 files changed, 31 insertions(+), 2 deletions(-)
diff --git a/dialects/linux/dsock.c b/dialects/linux/dsock.c
index 4b71460..0aaaf6d 100644
--- a/dialects/linux/dsock.c
+++ b/dialects/linux/dsock.c
@@ -3632,9 +3632,38 @@ net6a2in6(as, ad)
(void) strncpy(buf, as, 8);
buf[8] = '\0';
ep = (char *)NULL;
- if ((ad->s6_addr32[i] = (uint32_t)strtoul(buf, &ep, 16))
- == (uint32_t)UINT32_MAX || !ep || *ep)
+
+ errno = 0;
+ unsigned long ul_addr = strtoul(buf, &ep, 16);
+ if (!ep || *ep)
+ break;
+ else if (ul_addr == ULONG_MAX && errno == ERANGE)
+ {
+ /* Quoted from strtoul(3)
+ ---------------------------------------------------
+ The strtoul() function returns either the result of
+ the conversion or, if there was a leading minus
+ sign, the negation of the result of the conversion
+ represented as an unsigned value, unless the
+ original (nonnegated) value would overflow; in the
+ latter case, strtoul() returns ULONG_MAX and sets
+ errno to ERANGE.
+ ---------------------------------------------------
+ NOTE: even if the value doesn't overflow, a
+ negative is not acceptable. */
break;
+ }
+ else if (ul_addr > (unsigned long)UINT32_MAX)
+ {
+ /* This will never happen:
+ The maximum length of BUF is 8 characters.
+ The possible maximum value represented by BUF is
+ "FFFFFFFF". This is UINT32_MAX.
+ If you agree with what I write here, make a pull
+ request for removing this block. */
+ break;
+ }
+ ad->s6_addr32[i] = (uint32_t)ul_addr;
}
return((*as || (i != 4) || len) ? 1 : 0);
}