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v0.8.1
https://github.com/python/cpython
09 December 2020, 11:06:31 UTC
Revision b6e43af669f61a37a29d8ff0785455108e6bc29d authored by Christian Heimes on 29 January 2018, 21:37:58 UTC, committed by GitHub on 29 January 2018, 21:37:58 UTC 
bpo-28134: Auto-detect socket values from file descriptor (#1349)
 
Fix socket(fileno=fd) by auto-detecting the socket's family, type,
and proto from the file descriptor. The auto-detection can be overruled
by passing in family, type, and proto explicitly.

Without the fix, all socket except for TCP/IP over IPv4 are basically broken:

>>> s = socket.create_connection(('www.python.org', 443))
>>> s
<socket.socket fd=3, family=AddressFamily.AF_INET6, type=SocketKind.SOCK_STREAM, proto=6, laddr=('2003:58:bc4a:3b00:56ee:75ff:fe47:ca7b', 59730, 0, 0), raddr=('2a04:4e42:1b::223', 443, 0, 0)>
>>> socket.socket(fileno=s.fileno())
<socket.socket fd=3, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('2003:58:bc4a:3b00::%2550471192', 59730, 0, 2550471192), raddr=('2a04:4e42:1b:0:700c:e70b:ff7f:0%2550471192', 443, 0, 2550471192)>

Signed-off-by: Christian Heimes <christian@python.org>
1 parent 72a0d21
Raw File
Tip revision: b6e43af669f61a37a29d8ff0785455108e6bc29d authored by Christian Heimes on 29 January 2018, 21:37:58 UTC
bpo-28134: Auto-detect socket values from file descriptor (#1349)
Tip revision: b6e43af
dup2.c 
/*
 * Public domain dup2() lookalike
 * by Curtis Jackson @ AT&T Technologies, Burlington, NC
 * electronic address:  burl!rcj
 *
 * dup2 performs the following functions:
 *
 * Check to make sure that fd1 is a valid open file descriptor.
 * Check to see if fd2 is already open; if so, close it.
 * Duplicate fd1 onto fd2; checking to make sure fd2 is a valid fd.
 * Return fd2 if all went well; return BADEXIT otherwise.
 */

#include <fcntl.h>
#include <unistd.h>

#define BADEXIT -1

int
dup2(int fd1, int fd2)
{
    if (fd1 != fd2) {
        if (fcntl(fd1, F_GETFL) < 0)
            return BADEXIT;
        if (fcntl(fd2, F_GETFL) >= 0)
            close(fd2);
        if (fcntl(fd1, F_DUPFD, fd2) < 0)
            return BADEXIT;
    }
    return fd2;
}
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