xref: /freebsd/usr.bin/truss/syscalls.c (revision 6990ffd8a95caaba6858ad44ff1b3157d1efba8f)
1 /*
2  * Copryight 1997 Sean Eric Fagan
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  * 3. All advertising materials mentioning features or use of this software
13  *    must display the following acknowledgement:
14  *	This product includes software developed by Sean Eric Fagan
15  * 4. Neither the name of the author may be used to endorse or promote
16  *    products derived from this software without specific prior written
17  *    permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef lint
33 static const char rcsid[] =
34   "$FreeBSD$";
35 #endif /* not lint */
36 
37 /*
38  * This file has routines used to print out system calls and their
39  * arguments.
40  */
41 
42 #include <err.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <unistd.h>
47 #include <sys/types.h>
48 #include <signal.h>
49 #include "syscall.h"
50 
51 /*
52  * This should probably be in its own file.
53  */
54 
55 struct syscall syscalls[] = {
56 	{ "readlink", 1, 3,
57 	  { { String, 0 } , { String | OUT, 1 }, { Int, 2 }}},
58 	{ "lseek", 2, 3,
59 	  { { Int, 0 }, {Quad, 2 }, { Int, 4 }}},
60 	{ "mmap", 2, 6,
61 	  { { Hex, 0 }, {Int, 1}, {Hex, 2}, {Hex, 3}, {Int, 4}, {Quad, 6}}},
62 	{ "open", 1, 3,
63 	  { { String | IN, 0} , { Int, 1}, {Octal, 2}}},
64 	{ "linux_open", 1, 3,
65 	  { { String, 0 }, { Int, 1}, { Octal, 2 }}},
66 	{ "close", 1, 1, { { Int, 0 } } },
67 	{ "fstat", 1, 2,
68 	  { { Int, 0},  {Ptr | OUT , 1 }}},
69 	{ "stat", 1, 2,
70 	  { { String | IN, 0 }, { Ptr | OUT, 1 }}},
71 	{ "lstat", 1, 2,
72 	  { { String | IN, 0 }, { Ptr | OUT, 1 }}},
73 	{ "linux_newstat", 1, 2,
74 	  { { String | IN, 0 }, { Ptr | OUT, 1 }}},
75 	{ "linux_newfstat", 1, 2,
76 	  { { Int, 0 }, { Ptr | OUT, 1 }}},
77 	{ "write", 1, 3,
78 	  { { Int, 0}, { Ptr | IN, 1 }, { Int, 2 }}},
79 	{ "ioctl", 1, 3,
80 	  { { Int, 0}, { Ioctl, 1 }, { Hex, 2 }}},
81 	{ "break", 1, 1, { { Hex, 0 }}},
82 	{ "exit", 0, 1, { { Hex, 0 }}},
83 	{ "access", 1, 2, { { String | IN, 0 }, { Int, 1 }}},
84 	{ "sigaction", 1, 3,
85 	  { { Signal, 0 }, { Ptr | IN, 1 }, { Ptr | OUT, 2 }}},
86 	{ 0, 0, 0, { { 0, 0 }}},
87 };
88 
89 char * ioctlname __P((int));
90 
91 /*
92  * If/when the list gets big, it might be desirable to do it
93  * as a hash table or binary search.
94  */
95 
96 struct syscall *
97 get_syscall(const char *name) {
98 	struct syscall *sc = syscalls;
99 
100 	while (sc->name) {
101 		if (!strcmp(name, sc->name))
102 			return sc;
103 		sc++;
104 	}
105 	return NULL;
106 }
107 
108 /*
109  * get_string
110  * Copy a string from the process.  Note that it is
111  * expected to be a C string, but if max is set, it will
112  * only get that much.
113  */
114 
115 char *
116 get_string(int procfd, void *offset, int max) {
117 	char *buf;
118 	int size, len, c, fd;
119 	FILE *p;
120 
121 	if ((fd = dup(procfd)) == -1)
122 		err(1, "dup");
123 	if ((p = fdopen(fd, "r")) == NULL)
124 		err(1, "fdopen");
125 	buf = malloc( size = (max ? max : 64 ) );
126 	len = 0;
127 	buf[0] = 0;
128 	fseek(p, (long)offset, SEEK_SET);
129 	while ((c = fgetc(p)) != EOF) {
130 		buf[len++] = c;
131 		if (c == 0 || len == max) {
132 			buf[len] = 0;
133 			break;
134 		}
135 		if (len == size) {
136 			char *tmp;
137 			tmp = realloc(buf, size+64);
138 			if (tmp == NULL) {
139 				buf[len] = 0;
140 				fclose(p);
141 				return buf;
142 			}
143 			size += 64;
144 			buf = tmp;
145 		}
146 	}
147 	fclose(p);
148 	return buf;
149 }
150 
151 
152 /*
153  * Gag.  This is really unportable.  Multiplication is more portable.
154  * But slower, from the code I saw.
155  */
156 
157 static long long
158 make_quad(unsigned long p1, unsigned long p2) {
159   union {
160     long long ll;
161     unsigned long l[2];
162   } t;
163   t.l[0] = p1;
164   t.l[1] = p2;
165   return t.ll;
166 }
167 
168 
169 /*
170  * print_arg
171  * Converts a syscall argument into a string.  Said string is
172  * allocated via malloc(), so needs to be free()'d.  The file
173  * descriptor is for the process' memory (via /proc), and is used
174  * to get any data (where the argument is a pointer).  sc is
175  * a pointer to the syscall description (see above); args is
176  * an array of all of the system call arguments.
177  */
178 
179 char *
180 print_arg(int fd, struct syscall_args *sc, unsigned long *args) {
181   char *tmp = NULL;
182   switch (sc->type & ARG_MASK) {
183   case Hex:
184     tmp = malloc(12);
185     sprintf(tmp, "0x%lx", args[sc->offset]);
186     break;
187   case Octal:
188     tmp = malloc(13);
189     sprintf(tmp, "0%lo", args[sc->offset]);
190     break;
191   case Int:
192     tmp = malloc(12);
193     sprintf(tmp, "%ld", args[sc->offset]);
194     break;
195   case String:
196     {
197       char *tmp2;
198       tmp2 = get_string(fd, (void*)args[sc->offset], 0);
199       tmp = malloc(strlen(tmp2) + 3);
200       sprintf(tmp, "\"%s\"", tmp2);
201       free(tmp2);
202     }
203   break;
204   case Quad:
205     {
206       unsigned long long t;
207       unsigned long l1, l2;
208       l1 = args[sc->offset];
209       l2 = args[sc->offset+1];
210       t = make_quad(l1, l2);
211       tmp = malloc(24);
212       sprintf(tmp, "0x%qx", t);
213       break;
214     }
215   case Ptr:
216     tmp = malloc(12);
217     sprintf(tmp, "0x%lx", args[sc->offset]);
218     break;
219   case Ioctl:
220     {
221       char *temp = ioctlname(args[sc->offset]);
222       if (temp)
223 	tmp = strdup(temp);
224       else {
225 	tmp = malloc(12);
226 	sprintf(tmp, "0x%lx", args[sc->offset]);
227       }
228     }
229     break;
230   case Signal:
231     {
232       long sig;
233 
234       sig = args[sc->offset];
235       tmp = malloc(12);
236       if (sig > 0 && sig < NSIG) {
237 	int i;
238 	sprintf(tmp, "sig%s", sys_signame[sig]);
239 	for (i = 0; tmp[i] != '\0'; ++i)
240 	  tmp[i] = toupper(tmp[i]);
241       } else {
242         sprintf(tmp, "%ld", sig);
243       }
244     }
245     break;
246   }
247   return tmp;
248 }
249 
250 /*
251  * print_syscall
252  * Print (to outfile) the system call and its arguments.  Note that
253  * nargs is the number of arguments (not the number of words; this is
254  * potentially confusing, I know).
255  */
256 
257 void
258 print_syscall(FILE *outfile, const char *name, int nargs, char **s_args) {
259   int i;
260   int len = 0;
261   len += fprintf(outfile, "%s(", name);
262   for (i = 0; i < nargs; i++) {
263     if (s_args[i])
264       len += fprintf(outfile, "%s", s_args[i]);
265     else
266       len += fprintf(outfile, "<missing argument>");
267     len += fprintf(outfile, "%s", i < (nargs - 1) ? "," : "");
268   }
269   len += fprintf(outfile, ")");
270   for (i = 0; i < 6 - (len / 8); i++)
271 	fprintf(outfile, "\t");
272 }
273 
274 void
275 print_syscall_ret(FILE *outfile, const char *name, int nargs, char **s_args, int errorp, int retval) {
276   print_syscall(outfile, name, nargs, s_args);
277   if (errorp) {
278     fprintf(outfile, " ERR#%d '%s'\n", retval, strerror(retval));
279   } else {
280     fprintf(outfile, " = %d (0x%x)\n", retval, retval);
281   }
282 }
283