Ansify function declarations and fix some minor style issues.
[dragonfly.git] / sys / kern / imgact_gzip.c
1 /*
2  * ----------------------------------------------------------------------------
3  * "THE BEER-WARE LICENSE" (Revision 42):
4  * <phk@login.dkuug.dk> wrote this file.  As long as you retain this notice you
5  * can do whatever you want with this stuff. If we meet some day, and you think
6  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
7  * ----------------------------------------------------------------------------
8  *
9  * $FreeBSD: src/sys/kern/imgact_gzip.c,v 1.40.2.1 2001/11/03 01:41:08 ps Exp $
10  * $DragonFly: src/sys/kern/imgact_gzip.c,v 1.8 2006/12/23 23:47:54 swildner Exp $
11  *
12  * This module handles execution of a.out files which have been run through
13  * "gzip".  This saves diskspace, but wastes cpu-cycles and VM.
14  *
15  * TODO:
16  *      text-segments should be made R/O after being filled
17  *      is the vm-stuff safe ?
18  *      should handle the entire header of gzip'ed stuff.
19  *      inflate isn't quite reentrant yet...
20  *      error-handling is a mess...
21  *      so is the rest...
22  *      tidy up unnecesary includes
23  */
24
25 #include <sys/param.h>
26 #include <sys/exec.h>
27 #include <sys/imgact.h>
28 #include <sys/imgact_aout.h>
29 #include <sys/kernel.h>
30 #include <sys/mman.h>
31 #include <sys/proc.h>
32 #include <sys/resourcevar.h>
33 #include <sys/sysent.h>
34 #include <sys/systm.h>
35 #include <sys/vnode.h>
36 #include <sys/inflate.h>
37
38 #include <vm/vm.h>
39 #include <vm/vm_param.h>
40 #include <sys/lock.h>
41 #include <vm/pmap.h>
42 #include <vm/vm_map.h>
43 #include <vm/vm_kern.h>
44 #include <vm/vm_extern.h>
45
46 struct imgact_gzip {
47         struct image_params *ip;
48         struct exec     a_out;
49         int             error;
50         int             gotheader;
51         int             where;
52         u_char         *inbuf;
53         u_long          offset;
54         u_long          output;
55         u_long          len;
56         int             idx;
57         u_long          virtual_offset, file_offset, file_end, bss_size;
58 };
59
60 static int exec_gzip_imgact (struct image_params *imgp);
61 static int NextByte (void *vp);
62 static int do_aout_hdr (struct imgact_gzip *);
63 static int Flush (void *vp, u_char *, u_long siz);
64
65 static int
66 exec_gzip_imgact(struct image_params *imgp)
67 {
68         int             error, error2 = 0;
69         const u_char   *p = (const u_char *) imgp->image_header;
70         struct imgact_gzip igz;
71         struct inflate  infl;
72         struct vmspace *vmspace;
73
74         /* If these four are not OK, it isn't a gzip file */
75         if (p[0] != 0x1f)
76                 return -1;      /* 0    Simply magic     */
77         if (p[1] != 0x8b)
78                 return -1;      /* 1    Simply magic     */
79         if (p[2] != 0x08)
80                 return -1;      /* 2    Compression method       */
81         if (p[9] != 0x03)
82                 return -1;      /* 9    OS compressed on         */
83
84         /*
85          * If this one contains anything but a comment or a filename marker,
86          * we don't want to chew on it
87          */
88         if (p[3] & ~(0x18))
89                 return ENOEXEC; /* 3    Flags            */
90
91         /* These are of no use to us */
92         /* 4-7  Timestamp                */
93         /* 8    Extra flags              */
94
95         bzero(&igz, sizeof igz);
96         bzero(&infl, sizeof infl);
97         infl.gz_private = (void *) &igz;
98         infl.gz_input = NextByte;
99         infl.gz_output = Flush;
100
101         igz.ip = imgp;
102         igz.idx = 10;
103
104         if (p[3] & 0x08) {      /* skip a filename */
105                 while (p[igz.idx++])
106                         if (igz.idx >= PAGE_SIZE)
107                                 return ENOEXEC;
108         }
109         if (p[3] & 0x10) {      /* skip a comment */
110                 while (p[igz.idx++])
111                         if (igz.idx >= PAGE_SIZE)
112                                 return ENOEXEC;
113         }
114         igz.len = imgp->attr->va_size;
115
116         error = inflate(&infl);
117
118         /*
119          * The unzipped file may not even have been long enough to contain
120          * a header giving Flush() a chance to return error.  Check for this.
121          */
122         if ( !igz.gotheader )
123                 return ENOEXEC;
124
125         if ( !error ) {
126                 vmspace = imgp->proc->p_vmspace;
127                 error = vm_map_protect(&vmspace->vm_map,
128                         (vm_offset_t) vmspace->vm_taddr,
129                         (vm_offset_t) (vmspace->vm_taddr + 
130                                       (vmspace->vm_tsize << PAGE_SHIFT)) ,
131                         VM_PROT_READ|VM_PROT_EXECUTE,0);
132         }
133
134         if (igz.inbuf) {
135                 error2 =
136                         vm_map_remove(kernel_map, (vm_offset_t) igz.inbuf,
137                             (vm_offset_t) igz.inbuf + PAGE_SIZE);
138         }
139         if (igz.error || error || error2) {
140                 kprintf("Output=%lu ", igz.output);
141                 kprintf("Inflate_error=%d igz.error=%d error2=%d where=%d\n",
142                        error, igz.error, error2, igz.where);
143         }
144         if (igz.error)
145                 return igz.error;
146         if (error)
147                 return ENOEXEC;
148         if (error2)
149                 return error2;
150         return 0;
151 }
152
153 static int
154 do_aout_hdr(struct imgact_gzip * gz)
155 {
156         int             error;
157         struct vmspace *vmspace;
158         vm_offset_t     vmaddr;
159
160         /*
161          * Set file/virtual offset based on a.out variant. We do two cases:
162          * host byte order and network byte order (for NetBSD compatibility)
163          */
164         switch ((int) (gz->a_out.a_magic & 0xffff)) {
165         case ZMAGIC:
166                 gz->virtual_offset = 0;
167                 if (gz->a_out.a_text) {
168                         gz->file_offset = PAGE_SIZE;
169                 } else {
170                         /* Bill's "screwball mode" */
171                         gz->file_offset = 0;
172                 }
173                 break;
174         case QMAGIC:
175                 gz->virtual_offset = PAGE_SIZE;
176                 gz->file_offset = 0;
177                 break;
178         default:
179                 /* NetBSD compatibility */
180                 switch ((int) (ntohl(gz->a_out.a_magic) & 0xffff)) {
181                 case ZMAGIC:
182                 case QMAGIC:
183                         gz->virtual_offset = PAGE_SIZE;
184                         gz->file_offset = 0;
185                         break;
186                 default:
187                         gz->where = __LINE__;
188                         return (-1);
189                 }
190         }
191
192         gz->bss_size = roundup(gz->a_out.a_bss, PAGE_SIZE);
193
194         /*
195          * Check various fields in header for validity/bounds.
196          */
197         if (                    /* entry point must lay with text region */
198             gz->a_out.a_entry < gz->virtual_offset ||
199             gz->a_out.a_entry >= gz->virtual_offset + gz->a_out.a_text ||
200
201         /* text and data size must each be page rounded */
202             gz->a_out.a_text & PAGE_MASK || gz->a_out.a_data & PAGE_MASK) {
203                 gz->where = __LINE__;
204                 return (-1);
205         }
206         /*
207          * text/data/bss must not exceed limits
208          */
209         if (                    /* text can't exceed maximum text size */
210             gz->a_out.a_text > maxtsiz ||
211
212         /* data + bss can't exceed rlimit */
213             gz->a_out.a_data + gz->bss_size >
214             gz->ip->proc->p_rlimit[RLIMIT_DATA].rlim_cur) {
215                 gz->where = __LINE__;
216                 return (ENOMEM);
217         }
218         /* Find out how far we should go */
219         gz->file_end = gz->file_offset + gz->a_out.a_text + gz->a_out.a_data;
220
221         /*
222          * Destroy old process VM and create a new one (with a new stack)
223          */
224         exec_new_vmspace(gz->ip, NULL);
225
226         vmspace = gz->ip->proc->p_vmspace;
227
228         vmaddr = gz->virtual_offset;
229
230         error = vm_mmap(&vmspace->vm_map,
231                         &vmaddr,
232                         gz->a_out.a_text + gz->a_out.a_data,
233                         VM_PROT_ALL, VM_PROT_ALL, MAP_ANON | MAP_FIXED,
234                         0,
235                         0);
236
237         if (error) {
238                 gz->where = __LINE__;
239                 return (error);
240         }
241
242         if (gz->bss_size != 0) {
243                 /*
244                  * Allocate demand-zeroed area for uninitialized data.
245                  * "bss" = 'block started by symbol' - named after the 
246                  * IBM 7090 instruction of the same name.
247                  */
248                 vmaddr = gz->virtual_offset + gz->a_out.a_text + 
249                         gz->a_out.a_data;
250                 error = vm_map_find(&vmspace->vm_map,
251                                     NULL, 0,
252                                     &vmaddr, gz->bss_size,
253                                     FALSE,
254                                     VM_MAPTYPE_NORMAL,
255                                     VM_PROT_ALL, VM_PROT_ALL,
256                                     0);
257                 if (error) {
258                         gz->where = __LINE__;
259                         return (error);
260                 }
261         }
262         /* Fill in process VM information */
263         vmspace->vm_tsize = gz->a_out.a_text >> PAGE_SHIFT;
264         vmspace->vm_dsize = (gz->a_out.a_data + gz->bss_size) >> PAGE_SHIFT;
265         vmspace->vm_taddr = (caddr_t) (uintptr_t) gz->virtual_offset;
266         vmspace->vm_daddr = (caddr_t) (uintptr_t)
267                             (gz->virtual_offset + gz->a_out.a_text);
268
269         /* Fill in image_params */
270         gz->ip->interpreted = 0;
271         gz->ip->entry_addr = gz->a_out.a_entry;
272
273         gz->ip->proc->p_sysent = &aout_sysvec;
274
275         return 0;
276 }
277
278 static int
279 NextByte(void *vp)
280 {
281         int             error;
282         struct imgact_gzip *igz = (struct imgact_gzip *) vp;
283
284         if (igz->idx >= igz->len) {
285                 igz->where = __LINE__;
286                 return GZ_EOF;
287         }
288         if (igz->inbuf && igz->idx < (igz->offset + PAGE_SIZE)) {
289                 return igz->inbuf[(igz->idx++) - igz->offset];
290         }
291         if (igz->inbuf) {
292                 error = vm_map_remove(kernel_map, (vm_offset_t) igz->inbuf,
293                             (vm_offset_t) igz->inbuf + PAGE_SIZE);
294                 if (error) {
295                         igz->where = __LINE__;
296                         igz->error = error;
297                         return GZ_EOF;
298                 }
299         }
300         igz->offset = igz->idx & ~PAGE_MASK;
301
302         error = vm_mmap(kernel_map,     /* map */
303                         (vm_offset_t *) & igz->inbuf,   /* address */
304                         PAGE_SIZE,      /* size */
305                         VM_PROT_READ,   /* protection */
306                         VM_PROT_READ,   /* max protection */
307                         0,      /* flags */
308                         (caddr_t) igz->ip->vp,  /* vnode */
309                         igz->offset);   /* offset */
310         if (error) {
311                 igz->where = __LINE__;
312                 igz->error = error;
313                 return GZ_EOF;
314         }
315         return igz->inbuf[(igz->idx++) - igz->offset];
316 }
317
318 static int
319 Flush(void *vp, u_char * ptr, u_long siz)
320 {
321         struct imgact_gzip *gz = (struct imgact_gzip *) vp;
322         u_char         *p = ptr, *q;
323         int             i;
324
325         /* First, find a a.out-header */
326         if (gz->output < sizeof gz->a_out) {
327                 q = (u_char *) & gz->a_out;
328                 i = min(siz, sizeof gz->a_out - gz->output);
329                 bcopy(p, q + gz->output, i);
330                 gz->output += i;
331                 p += i;
332                 siz -= i;
333                 if (gz->output == sizeof gz->a_out) {
334                         gz->gotheader = 1;
335                         i = do_aout_hdr(gz);
336                         if (i == -1) {
337                                 if (!gz->where)
338                                         gz->where = __LINE__;
339                                 gz->error = ENOEXEC;
340                                 return ENOEXEC;
341                         } else if (i) {
342                                 gz->where = __LINE__;
343                                 gz->error = i;
344                                 return ENOEXEC;
345                         }
346                         if (gz->file_offset == 0) {
347                                 q = (u_char *) (uintptr_t) gz->virtual_offset;
348                                 copyout(&gz->a_out, q, sizeof gz->a_out);
349                         }
350                 }
351         }
352         /* Skip over zero-padded first PAGE if needed */
353         if (gz->output < gz->file_offset &&
354             gz->output + siz > gz->file_offset) {
355                 i = min(siz, gz->file_offset - gz->output);
356                 gz->output += i;
357                 p += i;
358                 siz -= i;
359         }
360         if (gz->output >= gz->file_offset && gz->output < gz->file_end) {
361                 i = min(siz, gz->file_end - gz->output);
362                 q = (u_char *) (uintptr_t)
363                     (gz->virtual_offset + gz->output - gz->file_offset);
364                 copyout(p, q, i);
365                 gz->output += i;
366                 p += i;
367                 siz -= i;
368         }
369         gz->output += siz;
370         return 0;
371 }
372
373
374 /*
375  * Tell kern_execve.c about it, with a little help from the linker.
376  */
377 static struct execsw gzip_execsw = {exec_gzip_imgact, "gzip"};
378 EXEC_SET(execgzip, gzip_execsw);