1 /* 2 * Author: Tatu Ylonen <ylo@cs.hut.fi> 3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 4 * All rights reserved 5 * 6 * As far as I am concerned, the code I have written for this software 7 * can be used freely for any purpose. Any derived versions of this 8 * software must be clearly marked as such, and if the derived work is 9 * incompatible with the protocol description in the RFC file, it must be 10 * called by a name other than "ssh" or "Secure Shell". 11 */ 12 13 #include "includes.h" 14 RCSID("$OpenBSD: tildexpand.c,v 1.13 2002/06/23 03:25:50 deraadt Exp $"); 15 16 #pragma ident "%Z%%M% %I% %E% SMI" 17 18 #include "xmalloc.h" 19 #include "log.h" 20 #include "tildexpand.h" 21 22 /* 23 * Expands tildes in the file name. Returns data allocated by xmalloc. 24 * Warning: this calls getpw*. 25 */ 26 char * 27 tilde_expand_filename(const char *filename, uid_t my_uid) 28 { 29 const char *cp; 30 u_int userlen; 31 char *expanded; 32 struct passwd *pw; 33 char user[100]; 34 int len; 35 36 /* Return immediately if no tilde. */ 37 if (filename[0] != '~') 38 return xstrdup(filename); 39 40 /* Skip the tilde. */ 41 filename++; 42 43 /* Find where the username ends. */ 44 cp = strchr(filename, '/'); 45 if (cp) 46 userlen = cp - filename; /* Something after username. */ 47 else 48 userlen = strlen(filename); /* Nothing after username. */ 49 if (userlen == 0) 50 pw = getpwuid(my_uid); /* Own home directory. */ 51 else { 52 /* Tilde refers to someone elses home directory. */ 53 if (userlen > sizeof(user) - 1) 54 fatal("User name after tilde too long."); 55 memcpy(user, filename, userlen); 56 user[userlen] = 0; 57 pw = getpwnam(user); 58 } 59 if (!pw) 60 fatal("Unknown user %100s.", user); 61 62 /* If referring to someones home directory, return it now. */ 63 if (!cp) { 64 /* Only home directory specified */ 65 return xstrdup(pw->pw_dir); 66 } 67 /* Build a path combining the specified directory and path. */ 68 len = strlen(pw->pw_dir) + strlen(cp + 1) + 2; 69 if (len > MAXPATHLEN) 70 fatal("Home directory too long (%d > %d", len-1, MAXPATHLEN-1); 71 expanded = xmalloc(len); 72 snprintf(expanded, len, "%s%s%s", pw->pw_dir, 73 strcmp(pw->pw_dir, "/") ? "/" : "", cp + 1); 74 return expanded; 75 } 76