Commit de6b9933 authored by Laurent Vivier's avatar Laurent Vivier Committed by Riku Voipio
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linux-user: convert /proc/net/route when endianess differs 



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: default avatarLaurent Vivier <laurent@vivier.eu>
Reviewed-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: default avatarRiku Voipio <riku.voipio@linaro.org>
parent 868e34d7

linux-user/syscall.c

+53 −5
Original line number Diff line number Diff line
@@ -5071,22 +5071,70 @@ static int is_proc_myself(const char *filename, const char *entry) 
    return 0;

}



#if defined(HOST_WORDS_BIGENDIAN) != defined(TARGET_WORDS_BIGENDIAN)

static int is_proc(const char *filename, const char *entry)

{

    return strcmp(filename, entry) == 0;

}



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 {

        const char *filename;

        int (*fill)(void *cpu_env, int fd);

        int (*cmp)(const char *s1, const char *s2);

    };

    const struct fake_open *fake_open;

    static const struct fake_open fakes[] = {

        { "maps", open_self_maps },

        { "stat", open_self_stat },

        { "auxv", open_self_auxv },

        { NULL, NULL }

        { "maps", open_self_maps, is_proc_myself },

        { "stat", open_self_stat, is_proc_myself },

        { "auxv", open_self_auxv, is_proc_myself },

#if defined(HOST_WORDS_BIGENDIAN) != defined(TARGET_WORDS_BIGENDIAN)

        { "/proc/net/route", open_net_route, is_proc },

#endif

        { NULL, NULL, NULL }

    };



    for (fake_open = fakes; fake_open->filename; fake_open++) {

        if (is_proc_myself(pathname, fake_open->filename)) {

        if (fake_open->cmp(pathname, fake_open->filename)) {

            break;

        }

    }