| 1 | /* |
| 2 | * Copyright (c) 1993, David Greenman |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in the |
| 12 | * documentation and/or other materials provided with the distribution. |
| 13 | * 3. All advertising materials mentioning features or use of this software |
| 14 | * must display the following acknowledgement: |
| 15 | * This product includes software developed by David Greenman |
| 16 | * 4. The name of the developer may be used to endorse or promote products |
| 17 | * derived from this software without specific prior written 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 REGENTS 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 | * $Id: shell_imgact.c,v 1.3 1993/12/11 06:55:33 davidg Exp davidg $ |
| 32 | */ |
| 33 | |
| 34 | #include "param.h" |
| 35 | #include "systm.h" |
| 36 | #include "resourcevar.h" |
| 37 | #include "imgact.h" |
| 38 | |
| 39 | #define SHELLMAGIC 0x2123 /* #! */ |
| 40 | #define MAXSHELLCMDLEN 64 |
| 41 | |
| 42 | /* |
| 43 | * Shell interpreter image activator. A interpreter name beginning |
| 44 | * at iparams->stringbase is the minimal successful exit requirement. |
| 45 | */ |
| 46 | int |
| 47 | exec_shell_imgact(iparams) |
| 48 | struct image_params *iparams; |
| 49 | { |
| 50 | const char *image_header = iparams->image_header; |
| 51 | const char *ihp, *line_endp; |
| 52 | int length; |
| 53 | char *interp; |
| 54 | char **argv; |
| 55 | |
| 56 | /* a shell script? */ |
| 57 | if (((short *) image_header)[0] != SHELLMAGIC) |
| 58 | return(-1); |
| 59 | |
| 60 | /* |
| 61 | * Don't allow a shell script to be the shell for a shell |
| 62 | * script. :-) |
| 63 | */ |
| 64 | if (iparams->interpreted) |
| 65 | return(ENOEXEC); |
| 66 | |
| 67 | iparams->interpreted = 1; |
| 68 | |
| 69 | /* |
| 70 | * Copy shell name and arguments from image_header into string |
| 71 | * buffer. |
| 72 | */ |
| 73 | |
| 74 | /* |
| 75 | * Find end of line; return if the line > MAXSHELLCMDLEN long. |
| 76 | */ |
| 77 | for (ihp = &image_header[2]; *ihp != '\n'; ++ihp) { |
| 78 | if (ihp >= &image_header[MAXSHELLCMDLEN]) |
| 79 | return(ENOEXEC); |
| 80 | } |
| 81 | line_endp = ihp; |
| 82 | |
| 83 | /* reset for another pass */ |
| 84 | ihp = &image_header[2]; |
| 85 | |
| 86 | /* Skip over leading spaces - until the interpreter name */ |
| 87 | while ((*ihp == ' ') || (*ihp == '\t')) ihp++; |
| 88 | |
| 89 | /* copy the interpreter name */ |
| 90 | interp = iparams->interpreter_name; |
| 91 | while ((ihp < line_endp) && (*ihp != ' ') && (*ihp != '\t')) |
| 92 | *interp++ = *ihp++; |
| 93 | *interp = '\0'; |
| 94 | |
| 95 | /* Disallow a null interpreter filename */ |
| 96 | if (*iparams->interpreter_name == '\0') |
| 97 | return(ENOEXEC); |
| 98 | |
| 99 | /* reset for another pass */ |
| 100 | ihp = &image_header[2]; |
| 101 | |
| 102 | /* copy the interpreter name and arguments */ |
| 103 | while (ihp < line_endp) { |
| 104 | /* Skip over leading spaces */ |
| 105 | while ((*ihp == ' ') || (*ihp == '\t')) ihp++; |
| 106 | |
| 107 | if (ihp < line_endp) { |
| 108 | /* |
| 109 | * Copy to end of token. No need to watch stringspace |
| 110 | * because this is at the front of the string buffer |
| 111 | * and the maximum shell command length is tiny. |
| 112 | */ |
| 113 | while ((ihp < line_endp) && (*ihp != ' ') && (*ihp != '\t')) { |
| 114 | *iparams->stringp++ = *ihp++; |
| 115 | iparams->stringspace--; |
| 116 | } |
| 117 | |
| 118 | *iparams->stringp++ = 0; |
| 119 | iparams->stringspace--; |
| 120 | |
| 121 | iparams->argc++; |
| 122 | } |
| 123 | } |
| 124 | |
| 125 | /* set argv[0] to point to original file name */ |
| 126 | suword(iparams->uap->argv, (int)iparams->uap->fname); |
| 127 | |
| 128 | return(0); |
| 129 | } |