LXR qemu/bsd-user/bsdload.c

   1/* Code for loading BSD executables.  Mostly linux kernel code.  */
   2
   3#include "qemu/osdep.h"
   4
   5#include "qemu.h"
   6
   7#define TARGET_NGROUPS 32
   8
   9/* ??? This should really be somewhere else.  */
  10abi_long memcpy_to_target(abi_ulong dest, const void *src,
  11                          unsigned long len)
  12{
  13    void *host_ptr;
  14
  15    host_ptr = lock_user(VERIFY_WRITE, dest, len, 0);
  16    if (!host_ptr)
  17        return -TARGET_EFAULT;
  18    memcpy(host_ptr, src, len);
  19    unlock_user(host_ptr, dest, 1);
  20    return 0;
  21}
  22
  23static int in_group_p(gid_t g)
  24{
  25    /* return TRUE if we're in the specified group, FALSE otherwise */
  26    int         ngroup;
  27    int         i;
  28    gid_t       grouplist[TARGET_NGROUPS];
  29
  30    ngroup = getgroups(TARGET_NGROUPS, grouplist);
  31    for(i = 0; i < ngroup; i++) {
  32        if(grouplist[i] == g) {
  33            return 1;
  34        }
  35    }
  36    return 0;
  37}
  38
  39static int count(char ** vec)
  40{
  41    int         i;
  42
  43    for(i = 0; *vec; i++) {
  44        vec++;
  45    }
  46
  47    return(i);
  48}
  49
  50static int prepare_binprm(struct linux_binprm *bprm)
  51{
  52    struct stat         st;
  53    int mode;
  54    int retval, id_change;
  55
  56    if(fstat(bprm->fd, &st) < 0) {
  57        return(-errno);
  58    }
  59
  60    mode = st.st_mode;
  61    if(!S_ISREG(mode)) {        /* Must be regular file */
  62        return(-EACCES);
  63    }
  64    if(!(mode & 0111)) {        /* Must have at least one execute bit set */
  65        return(-EACCES);
  66    }
  67
  68    bprm->e_uid = geteuid();
  69    bprm->e_gid = getegid();
  70    id_change = 0;
  71
  72    /* Set-uid? */
  73    if(mode & S_ISUID) {
  74        bprm->e_uid = st.st_uid;
  75        if(bprm->e_uid != geteuid()) {
  76            id_change = 1;
  77        }
  78    }
  79
  80    /* Set-gid? */
  81    /*
  82     * If setgid is set but no group execute bit then this
  83     * is a candidate for mandatory locking, not a setgid
  84     * executable.
  85     */
  86    if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
  87        bprm->e_gid = st.st_gid;
  88        if (!in_group_p(bprm->e_gid)) {
  89                id_change = 1;
  90        }
  91    }
  92
  93    memset(bprm->buf, 0, sizeof(bprm->buf));
  94    retval = lseek(bprm->fd, 0L, SEEK_SET);
  95    if(retval >= 0) {
  96        retval = read(bprm->fd, bprm->buf, 128);
  97    }
  98    if(retval < 0) {
  99        perror("prepare_binprm");
 100        exit(-1);
 101        /* return(-errno); */
 102    }
 103    else {
 104        return(retval);
 105    }
 106}
 107
 108/* Construct the envp and argv tables on the target stack.  */
 109abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
 110                              abi_ulong stringp, int push_ptr)
 111{
 112    int n = sizeof(abi_ulong);
 113    abi_ulong envp;
 114    abi_ulong argv;
 115
 116    sp -= (envc + 1) * n;
 117    envp = sp;
 118    sp -= (argc + 1) * n;
 119    argv = sp;
 120    if (push_ptr) {
 121        /* FIXME - handle put_user() failures */
 122        sp -= n;
 123        put_user_ual(envp, sp);
 124        sp -= n;
 125        put_user_ual(argv, sp);
 126    }
 127    sp -= n;
 128    /* FIXME - handle put_user() failures */
 129    put_user_ual(argc, sp);
 130
 131    while (argc-- > 0) {
 132        /* FIXME - handle put_user() failures */
 133        put_user_ual(stringp, argv);
 134        argv += n;
 135        stringp += target_strlen(stringp) + 1;
 136    }
 137    /* FIXME - handle put_user() failures */
 138    put_user_ual(0, argv);
 139    while (envc-- > 0) {
 140        /* FIXME - handle put_user() failures */
 141        put_user_ual(stringp, envp);
 142        envp += n;
 143        stringp += target_strlen(stringp) + 1;
 144    }
 145    /* FIXME - handle put_user() failures */
 146    put_user_ual(0, envp);
 147
 148    return sp;
 149}
 150
 151int loader_exec(const char * filename, char ** argv, char ** envp,
 152             struct target_pt_regs * regs, struct image_info *infop)
 153{
 154    struct linux_binprm bprm;
 155    int retval;
 156    int i;
 157
 158    bprm.p = TARGET_PAGE_SIZE*MAX_ARG_PAGES-sizeof(unsigned int);
 159    for (i=0 ; i<MAX_ARG_PAGES ; i++)       /* clear page-table */
 160            bprm.page[i] = NULL;
 161    retval = open(filename, O_RDONLY);
 162    if (retval < 0)
 163        return retval;
 164    bprm.fd = retval;
 165    bprm.filename = (char *)filename;
 166    bprm.argc = count(argv);
 167    bprm.argv = argv;
 168    bprm.envc = count(envp);
 169    bprm.envp = envp;
 170
 171    retval = prepare_binprm(&bprm);
 172
 173    if(retval>=0) {
 174        if (bprm.buf[0] == 0x7f
 175                && bprm.buf[1] == 'E'
 176                && bprm.buf[2] == 'L'
 177                && bprm.buf[3] == 'F') {
 178            retval = load_elf_binary(&bprm,regs,infop);
 179        } else {
 180            fprintf(stderr, "Unknown binary format\n");
 181            return -1;
 182        }
 183    }
 184
 185    if(retval>=0) {
 186        /* success.  Initialize important registers */
 187        do_init_thread(regs, infop);
 188        return retval;
 189    }
 190
 191    /* Something went wrong, return the inode and free the argument pages*/
 192    for (i=0 ; i<MAX_ARG_PAGES ; i++) {
 193        g_free(bprm.page[i]);
 194    }
 195    return(retval);
 196}
 197