Re: [Qemu-devel] [PATCH] linux-user: convert /proc/net/route when endianess differs

[Laurent Vivier]

Ping !


Le jeudi 20 décembre 2012 à 21:53 +0100, Laurent Vivier a écrit :
> This patch allows to have IP addresses in correct order
> in the case of "netstat -nr" when the endianess of the
> guest differs from one of the host.
> 
> For instance, an m68k guest on an x86_64 host:
> 
> WITHOUT this patch:
> 
> $ netstat -nr
> Kernel IP routing table
> Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
> 0.0.0.0         1.3.0.10        0.0.0.0         UG        0 0          0 eth0
> 0.3.0.10        0.0.0.0         0.255.255.255   U         0 0          0 eth0
> $ cat /proc/net/route
> Iface Destination     Gateway         Flags   RefCnt  Use     Metric  Mask    
> MTU     Window  IRTT
> 
> eth0  00000000        0103000A        0003    0       0       0       
> 000000000       0       0
> eth0  0003000A        00000000        0001    0       0       0       
> 00FFFFFF0       0       0
> 
> WITH this patch:
> 
> $ netstat -nr
> Kernel IP routing table
> Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
> 0.0.0.0         10.0.3.1        0.0.0.0         UG        0 0          0 eth0
> 10.0.3.0        0.0.0.0         255.255.255.0   U         0 0          0 eth0
> $ cat /proc/net/route
> Iface Destination     Gateway         Flags   RefCnt  Use     Metric  Mask    
> MTU     Window  IRTT
> eth0  00000000        0a000301        0003    0       0       0       
> 000000000       0       0
> eth0  0a000300        00000000        0001    0       0       0       
> ffffff000       0       0
> 
> Signed-off-by: Laurent Vivier <address@hidden>
> ---
>  linux-user/syscall.c |   42 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 42 insertions(+)
> 
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index e99adab..501002b 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -5085,6 +5085,45 @@ static int open_self_auxv(void *cpu_env, int fd)
>      return 0;
>  }
>  
> +#if defined(HOST_WORDS_BIGENDIAN) != defined(TARGET_WORDS_BIGENDIAN)
> +static int open_net_route(void *cpu_env, int fd)
> +{
> +    FILE *fp;
> +    char *line = NULL;
> +    size_t len = 0;
> +    ssize_t read;
> +
> +    fp = fopen("/proc/net/route", "r");
> +    if (fp == NULL) {
> +        return -EACCES;
> +    }
> +
> +    /* read header */
> +
> +    read = getline(&line, &len, fp);
> +    dprintf(fd, "%s", line);
> +
> +    /* read routes */
> +
> +    while ((read = getline(&line, &len, fp)) != -1) {
> +        char iface[16];
> +        uint32_t dest, gw, mask;
> +        unsigned int flags, refcnt, use, metric, mtu, window, irtt;
> +        sscanf(line, "%s\t%08x\t%08x\t%04x\t%d\t%d\t%d\t%08x\t%d\t%u\t%u\n",
> +                     iface, &dest, &gw, &flags, &refcnt, &use, &metric,
> +                     &mask, &mtu, &window, &irtt);
> +        dprintf(fd, "%s\t%08x\t%08x\t%04x\t%d\t%d\t%d\t%08x\t%d\t%u\t%u\n",
> +                iface, tswap32(dest), tswap32(gw), flags, refcnt, use,
> +                metric, tswap32(mask), mtu, window, irtt);
> +    }
> +
> +    free(line);
> +    fclose(fp);
> +
> +    return 0;
> +}
> +#endif
> +
>  static int do_open(void *cpu_env, const char *pathname, int flags, mode_t 
> mode)
>  {
>      struct fake_open {
> @@ -5096,6 +5135,9 @@ static int do_open(void *cpu_env, const char *pathname, 
> int flags, mode_t mode)
>          { "/proc/self/maps", open_self_maps },
>          { "/proc/self/stat", open_self_stat },
>          { "/proc/self/auxv", open_self_auxv },
> +#if defined(HOST_WORDS_BIGENDIAN) != defined(TARGET_WORDS_BIGENDIAN)
> +        { "/proc/net/route", open_net_route },
> +#endif
>          { NULL, NULL }
>      };
>  

-- 
"Just play. Have fun. Enjoy the game."
- Michael Jordan
"Just play. Have fun. Enjoy the game."
- Michael Jordan