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 "$Id: syscalls.c,v 1.4 1998/01/05 07:30:25 charnier Exp $"; 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 "syscall.h" 49 50 /* 51 * This should probably be in its own file. 52 */ 53 54 struct syscall syscalls[] = { 55 { "readlink", 1, 3, 56 { { String, 0 } , { String | OUT, 1 }, { Int, 2 }}}, 57 { "lseek", 2, 3, 58 { { Int, 0 }, {Quad, 2 }, { Int, 4 }}}, 59 { "mmap", 2, 6, 60 { { Hex, 0 }, {Int, 1}, {Hex, 2}, {Hex, 3}, {Int, 4}, {Quad, 6}}}, 61 { "open", 1, 3, 62 { { String | IN, 0} , { Int, 1}, {Octal, 2}}}, 63 { "linux_open", 1, 3, 64 { { String, 0 }, { Int, 1}, { Octal, 2 }}}, 65 { "close", 1, 1, { { Int, 0 } } }, 66 { "fstat", 1, 2, 67 { { Int, 0}, {Ptr | OUT , 1 }}}, 68 { "stat", 1, 2, 69 { { String | IN, 0 }, { Ptr | OUT, 1 }}}, 70 { "linux_newstat", 1, 2, 71 { { String | IN, 0 }, { Ptr | OUT, 1 }}}, 72 { "linux_newfstat", 1, 2, 73 { { Int, 0 }, { Ptr | OUT, 1 }}}, 74 { "write", 1, 3, 75 { { Int, 0}, { Ptr | IN, 1 }, { Int, 2 }}}, 76 { "ioctl", 1, 3, 77 { { Int, 0}, { Ioctl, 1 }, { Hex, 2 }}}, 78 { "break", 1, 1, { { Hex, 0 }}}, 79 { "exit", 0, 1, { { Hex, 0 }}}, 80 { 0, 0, 0, { { 0, 0 }}}, 81 }; 82 83 char * ioctlname __P((int)); 84 85 /* 86 * If/when the list gets big, it might be desirable to do it 87 * as a hash table or binary search. 88 */ 89 90 struct syscall * 91 get_syscall(const char *name) { 92 struct syscall *sc = syscalls; 93 94 while (sc->name) { 95 if (!strcmp(name, sc->name)) 96 return sc; 97 sc++; 98 } 99 return NULL; 100 } 101 102 /* 103 * get_string 104 * Copy a string from the process. Note that it is 105 * expected to be a C string, but if max is set, it will 106 * only get that much. 107 */ 108 109 char * 110 get_string(int procfd, void *offset, int max) { 111 char *buf; 112 int size, len, c; 113 FILE *p; 114 115 if ((p = fdopen(procfd, "r")) == NULL) 116 err(1, "fdopen"); 117 buf = malloc( size = (max ? max : 64 ) ); 118 len = 0; 119 fseek(p, (long)offset, SEEK_SET); 120 while ((c = fgetc(p)) != EOF) { 121 buf[len++] = c; 122 if (c == 0 || len == max) { 123 buf[len] = 0; 124 break; 125 } 126 if (len == size) { 127 char *tmp = buf; 128 tmp = realloc(buf, size+64); 129 if (tmp == NULL) { 130 buf[len] = 0; 131 return buf; 132 } 133 size += 64; 134 } 135 } 136 return buf; 137 } 138 139 140 /* 141 * Gag. This is really unportable. Multiplication is more portable. 142 * But slower, from the code I saw. 143 */ 144 145 static long long 146 make_quad(unsigned long p1, unsigned long p2) { 147 union { 148 long long ll; 149 unsigned long l[2]; 150 } t; 151 t.l[0] = p1; 152 t.l[1] = p2; 153 return t.ll; 154 } 155 156 157 /* 158 * print_arg 159 * Converts a syscall argument into a string. Said string is 160 * allocated via malloc(), so needs to be free()'d. The file 161 * descriptor is for the process' memory (via /proc), and is used 162 * to get any data (where the argument is a pointer). sc is 163 * a pointer to the syscall description (see above); args is 164 * an array of all of the system call arguments. 165 */ 166 167 char * 168 print_arg(int fd, struct syscall_args *sc, unsigned long *args) { 169 char *tmp = NULL; 170 switch (sc->type & ARG_MASK) { 171 case Hex: 172 tmp = malloc(12); 173 sprintf(tmp, "0x%lx", args[sc->offset]); 174 break; 175 case Octal: 176 tmp = malloc(13); 177 sprintf(tmp, "0%lo", args[sc->offset]); 178 break; 179 case Int: 180 tmp = malloc(12); 181 sprintf(tmp, "%ld", args[sc->offset]); 182 break; 183 case String: 184 { 185 char *tmp2; 186 tmp2 = get_string(fd, (void*)args[sc->offset], 0); 187 tmp = malloc(strlen(tmp2) + 3); 188 sprintf(tmp, "\"%s\"", tmp2); 189 free(tmp2); 190 } 191 break; 192 case Quad: 193 { 194 unsigned long long t; 195 unsigned long l1, l2; 196 l1 = args[sc->offset]; 197 l2 = args[sc->offset+1]; 198 t = make_quad(l1, l2); 199 tmp = malloc(24); 200 sprintf(tmp, "0x%qx", t); 201 break; 202 } 203 case Ptr: 204 tmp = malloc(12); 205 sprintf(tmp, "0x%lx", args[sc->offset]); 206 break; 207 case Ioctl: 208 { 209 char *temp = ioctlname(args[sc->offset]); 210 if (temp) 211 tmp = strdup(temp); 212 else { 213 tmp = malloc(12); 214 sprintf(tmp, "0x%lx", args[sc->offset]); 215 } 216 } 217 } 218 return tmp; 219 } 220 221 /* 222 * print_syscall 223 * Print (to outfile) the system call and its arguments. Note that 224 * nargs is the number of arguments (not the number of words; this is 225 * potentially confusing, I know). 226 */ 227 228 void 229 print_syscall(FILE *outfile, const char *name, int nargs, char **s_args) { 230 int i; 231 fprintf(outfile, "syscall %s(", name); 232 for (i = 0; i < nargs; i++) { 233 if (s_args[i]) 234 fprintf(outfile, "%s", s_args[i]); 235 else 236 fprintf(outfile, "<missing argument>"); 237 fprintf(outfile, "%s", i < (nargs - 1) ? "," : ""); 238 } 239 fprintf(outfile, ")\n\t"); 240 } 241