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.  */
  10 abi_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
  23 static 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
  39 static int count(char ** vec)
  40 {
  41     int         i;
  42
  43     for(i = 0; *vec; i++) {
  44         vec++;
  45     }
  46
  47     return(i);
  48 }
  49
  50 static 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.  */
 109 abi_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
 151 int 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 }