graphene/LibOS/shim/src/fs/proc/info.c

#include <shim_internal.h>
#include <shim_fs.h>

#include <pal.h>
#include <pal_error.h>

#include <errno.h>

#include <linux/stat.h>
#include <linux/fcntl.h>

#include <asm/fcntl.h>
#include <asm/mman.h>
#include <asm/unistd.h>
#include <asm/prctl.h>

static int proc_info_mode (const char * name, mode_t * mode)
{
    // The path is implicitly set by calling this function
    __UNUSED(name);
    *mode = 0444;
    return 0;
}

static int proc_info_stat (const char * name, struct stat * buf)
{
    // The path is implicitly set by calling this function
    __UNUSED(name);
    memset(buf, 0, sizeof(struct stat));
    buf->st_dev = buf->st_ino = 1;
    buf->st_mode = 0444|S_IFREG;
    buf->st_uid = 0;
    buf->st_gid = 0;
    buf->st_size = 0;
    return 0;
}

static int proc_meminfo_open (struct shim_handle * hdl, const char * name,
                              int flags)
{
    // This function only serves one file
    __UNUSED(name);
    if (flags & (O_WRONLY|O_RDWR))
        return -EACCES;

    int len, max = 128;
    char * str = NULL;

    struct { const char * fmt; unsigned long val; }
        meminfo[] = {
            { "MemTotal:      %8lu kB\n", pal_control.mem_info.mem_total / 1024, },
            { "MemFree:       %8lu kB\n", DkMemoryAvailableQuota() / 1024, },
        };

retry:
    max *= 2;
    len = 0;
    free(str);
    str = malloc(max);
    if (!str)
        return -ENOMEM;

    for (size_t i = 0 ; i < sizeof(meminfo) / sizeof(meminfo[0]) ; i++) {
        int ret = snprintf(str + len, max - len, meminfo[i].fmt,
                           meminfo[i].val);

        if (len + ret == max)
            goto retry;

        len += ret;
    }

    struct shim_str_data * data = malloc(sizeof(struct shim_str_data));
    if (!data) {
        free(str);
        return -ENOMEM;
    }

    memset(data, 0, sizeof(struct shim_str_data));
    data->str = str;
    data->len = len;
    hdl->type = TYPE_STR;
    hdl->flags = flags & ~O_RDONLY;
    hdl->acc_mode = MAY_READ;
    hdl->info.str.data = data;
    return 0;
}

static int proc_cpuinfo_open (struct shim_handle * hdl, const char * name,
                              int flags)
{
    // This function only serves one file
    __UNUSED(name);

    if (flags & (O_WRONLY|O_RDWR))
        return -EACCES;

    int len, max = 128;
    char * str = NULL;

    struct { const char * fmt; unsigned long val; }
        /* below strings must match exactly the strings retrieved from
         * /proc/cpuinfo (see Linux's arch/x86/kernel/cpu/proc.c) */
        cpuinfo[] = {
            { "processor\t: %lu\n",  0, },
            { "vendor_id\t: %s\n",   (unsigned long) pal_control.cpu_info.cpu_vendor, },
            { "cpu family\t: %lu\n", pal_control.cpu_info.cpu_family, },
            { "model\t\t: %lu\n",    pal_control.cpu_info.cpu_model, },
            { "model name\t: %s\n",  (unsigned long) pal_control.cpu_info.cpu_brand, },
            { "stepping\t: %lu\n",   pal_control.cpu_info.cpu_stepping, },
            { "core id\t\t: %lu\n",  0, },
            { "cpu cores\t: %lu\n",  pal_control.cpu_info.cpu_num, },
        };

retry:
    max *= 2;
    len = 0;
    free(str);
    str = malloc(max);
    if (!str)
        return -ENOMEM;

    for (size_t n = 0 ; n < pal_control.cpu_info.cpu_num ; n++) {
        cpuinfo[0].val = n;
        cpuinfo[6].val = n;
        for (size_t i = 0 ; i < sizeof(cpuinfo) / sizeof(cpuinfo[0]) ; i++) {
            int ret = snprintf(str + len, max - len, cpuinfo[i].fmt,
                               cpuinfo[i].val);

            if (len + ret == max)
                goto retry;

            len += ret;
        }

        if (len >= max - 1)
            goto retry;

        str[len++] = '\n';
        str[len] = 0;
    }

    struct shim_str_data * data = calloc(1, sizeof(struct shim_str_data));
    if (!data) {
        free(str);
        return -ENOMEM;
    }

    data->str = str;
    data->len = len;
    hdl->type = TYPE_STR;
    hdl->flags = flags & ~O_RDONLY;
    hdl->acc_mode = MAY_READ;
    hdl->info.str.data = data;
    return 0;
}

struct proc_fs_ops fs_meminfo = {
        .mode     = &proc_info_mode,
        .stat     = &proc_info_stat,
        .open     = &proc_meminfo_open,
    };

struct proc_fs_ops fs_cpuinfo = {
        .mode     = &proc_info_mode,
        .stat     = &proc_info_stat,
        .open     = &proc_cpuinfo_open,
    };