xref: /illumos-kvm-cmd/bsd-user/bsdload.c (revision 68396ea9)
1 /* Code for loading BSD executables.  Mostly linux kernel code.  */
2 
3 #include <sys/types.h>
4 #include <sys/stat.h>
5 #include <fcntl.h>
6 #include <errno.h>
7 #include <unistd.h>
8 #include <stdio.h>
9 #include <stdlib.h>
10 
11 #include "qemu.h"
12 
13 #define TARGET_NGROUPS 32
14 
15 /* ??? This should really be somewhere else.  */
memcpy_to_target(abi_ulong dest,const void * src,unsigned long len)16 abi_long memcpy_to_target(abi_ulong dest, const void *src,
17                           unsigned long len)
18 {
19     void *host_ptr;
20 
21     host_ptr = lock_user(VERIFY_WRITE, dest, len, 0);
22     if (!host_ptr)
23         return -TARGET_EFAULT;
24     memcpy(host_ptr, src, len);
25     unlock_user(host_ptr, dest, 1);
26     return 0;
27 }
28 
in_group_p(gid_t g)29 static int in_group_p(gid_t g)
30 {
31     /* return TRUE if we're in the specified group, FALSE otherwise */
32     int         ngroup;
33     int         i;
34     gid_t       grouplist[TARGET_NGROUPS];
35 
36     ngroup = getgroups(TARGET_NGROUPS, grouplist);
37     for(i = 0; i < ngroup; i++) {
38         if(grouplist[i] == g) {
39             return 1;
40         }
41     }
42     return 0;
43 }
44 
count(char ** vec)45 static int count(char ** vec)
46 {
47     int         i;
48 
49     for(i = 0; *vec; i++) {
50         vec++;
51     }
52 
53     return(i);
54 }
55 
prepare_binprm(struct linux_binprm * bprm)56 static int prepare_binprm(struct linux_binprm *bprm)
57 {
58     struct stat         st;
59     int mode;
60     int retval, id_change;
61 
62     if(fstat(bprm->fd, &st) < 0) {
63         return(-errno);
64     }
65 
66     mode = st.st_mode;
67     if(!S_ISREG(mode)) {        /* Must be regular file */
68         return(-EACCES);
69     }
70     if(!(mode & 0111)) {        /* Must have at least one execute bit set */
71         return(-EACCES);
72     }
73 
74     bprm->e_uid = geteuid();
75     bprm->e_gid = getegid();
76     id_change = 0;
77 
78     /* Set-uid? */
79     if(mode & S_ISUID) {
80         bprm->e_uid = st.st_uid;
81         if(bprm->e_uid != geteuid()) {
82             id_change = 1;
83         }
84     }
85 
86     /* Set-gid? */
87     /*
88      * If setgid is set but no group execute bit then this
89      * is a candidate for mandatory locking, not a setgid
90      * executable.
91      */
92     if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
93         bprm->e_gid = st.st_gid;
94         if (!in_group_p(bprm->e_gid)) {
95                 id_change = 1;
96         }
97     }
98 
99     memset(bprm->buf, 0, sizeof(bprm->buf));
100     retval = lseek(bprm->fd, 0L, SEEK_SET);
101     if(retval >= 0) {
102         retval = read(bprm->fd, bprm->buf, 128);
103     }
104     if(retval < 0) {
105         perror("prepare_binprm");
106         exit(-1);
107         /* return(-errno); */
108     }
109     else {
110         return(retval);
111     }
112 }
113 
114 /* Construct the envp and argv tables on the target stack.  */
loader_build_argptr(int envc,int argc,abi_ulong sp,abi_ulong stringp,int push_ptr)115 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
116                               abi_ulong stringp, int push_ptr)
117 {
118     int n = sizeof(abi_ulong);
119     abi_ulong envp;
120     abi_ulong argv;
121 
122     sp -= (envc + 1) * n;
123     envp = sp;
124     sp -= (argc + 1) * n;
125     argv = sp;
126     if (push_ptr) {
127         /* FIXME - handle put_user() failures */
128         sp -= n;
129         put_user_ual(envp, sp);
130         sp -= n;
131         put_user_ual(argv, sp);
132     }
133     sp -= n;
134     /* FIXME - handle put_user() failures */
135     put_user_ual(argc, sp);
136 
137     while (argc-- > 0) {
138         /* FIXME - handle put_user() failures */
139         put_user_ual(stringp, argv);
140         argv += n;
141         stringp += target_strlen(stringp) + 1;
142     }
143     /* FIXME - handle put_user() failures */
144     put_user_ual(0, argv);
145     while (envc-- > 0) {
146         /* FIXME - handle put_user() failures */
147         put_user_ual(stringp, envp);
148         envp += n;
149         stringp += target_strlen(stringp) + 1;
150     }
151     /* FIXME - handle put_user() failures */
152     put_user_ual(0, envp);
153 
154     return sp;
155 }
156 
loader_exec(const char * filename,char ** argv,char ** envp,struct target_pt_regs * regs,struct image_info * infop)157 int loader_exec(const char * filename, char ** argv, char ** envp,
158              struct target_pt_regs * regs, struct image_info *infop)
159 {
160     struct linux_binprm bprm;
161     int retval;
162     int i;
163 
164     bprm.p = TARGET_PAGE_SIZE*MAX_ARG_PAGES-sizeof(unsigned int);
165     for (i=0 ; i<MAX_ARG_PAGES ; i++)       /* clear page-table */
166             bprm.page[i] = NULL;
167     retval = open(filename, O_RDONLY);
168     if (retval < 0)
169         return retval;
170     bprm.fd = retval;
171     bprm.filename = (char *)filename;
172     bprm.argc = count(argv);
173     bprm.argv = argv;
174     bprm.envc = count(envp);
175     bprm.envp = envp;
176 
177     retval = prepare_binprm(&bprm);
178 
179     if(retval>=0) {
180         if (bprm.buf[0] == 0x7f
181                 && bprm.buf[1] == 'E'
182                 && bprm.buf[2] == 'L'
183                 && bprm.buf[3] == 'F') {
184             retval = load_elf_binary(&bprm,regs,infop);
185         } else {
186             fprintf(stderr, "Unknown binary format\n");
187             return -1;
188         }
189     }
190 
191     if(retval>=0) {
192         /* success.  Initialize important registers */
193         do_init_thread(regs, infop);
194         return retval;
195     }
196 
197     /* Something went wrong, return the inode and free the argument pages*/
198     for (i=0 ; i<MAX_ARG_PAGES ; i++) {
199         free(bprm.page[i]);
200     }
201     return(retval);
202 }
203