1 /* $NetBSD: include.c,v 1.1.1.1 2009/06/23 10:08:48 tron Exp $ */ 2 3 /*++ 4 /* NAME 5 /* deliver_include 3 6 /* SUMMARY 7 /* deliver to addresses listed in include file 8 /* SYNOPSIS 9 /* #include "local.h" 10 /* 11 /* int deliver_include(state, usr_attr, path) 12 /* LOCAL_STATE state; 13 /* USER_ATTR usr_attr; 14 /* char *path; 15 /* DESCRIPTION 16 /* deliver_include() processes the contents of the named include 17 /* file and delivers to each address listed. Some sanity checks 18 /* are done on the include file permissions and type. 19 /* 20 /* Arguments: 21 /* .IP state 22 /* The attributes that specify the message, recipient and more. 23 /* Attributes describing alias, include, or forward expansion. 24 /* A table with the results from expanding aliases or lists. 25 /* A table with delivered-to: addresses taken from the message. 26 /* .IP usr_attr 27 /* Attributes describing user rights and environment. 28 /* .IP path 29 /* Pathname of the include file. 30 /* DIAGNOSTICS 31 /* Fatal errors: out of memory. Warnings: bad include file type 32 /* or permissions. The result is non-zero when delivery should be 33 /* tried again. 34 /* SEE ALSO 35 /* token(3) tokenize list 36 /* LICENSE 37 /* .ad 38 /* .fi 39 /* The Secure Mailer license must be distributed with this software. 40 /* AUTHOR(S) 41 /* Wietse Venema 42 /* IBM T.J. Watson Research 43 /* P.O. Box 704 44 /* Yorktown Heights, NY 10598, USA 45 /*--*/ 46 47 /* System library. */ 48 49 #include <sys_defs.h> 50 #include <sys/stat.h> 51 #include <unistd.h> 52 #include <string.h> 53 #include <fcntl.h> 54 55 /* Utility library. */ 56 57 #include <msg.h> 58 #include <htable.h> 59 #include <mymalloc.h> 60 #include <vstream.h> 61 #include <open_as.h> 62 #include <stat_as.h> 63 #include <iostuff.h> 64 #include <mypwd.h> 65 66 /* Global library. */ 67 68 #include <bounce.h> 69 #include <defer.h> 70 #include <been_here.h> 71 #include <mail_params.h> 72 #include <ext_prop.h> 73 #include <sent.h> 74 75 /* Application-specific. */ 76 77 #include "local.h" 78 79 /* deliver_include - open include file and deliver */ 80 81 int deliver_include(LOCAL_STATE state, USER_ATTR usr_attr, char *path) 82 { 83 const char *myname = "deliver_include"; 84 struct stat st; 85 struct mypasswd *file_pwd = 0; 86 int status; 87 VSTREAM *fp; 88 int fd; 89 90 /* 91 * Make verbose logging easier to understand. 92 */ 93 state.level++; 94 if (msg_verbose) 95 MSG_LOG_STATE(myname, state); 96 97 /* 98 * DUPLICATE ELIMINATION 99 * 100 * Don't process this include file more than once as this particular user. 101 */ 102 if (been_here(state.dup_filter, "include %ld %s", (long) usr_attr.uid, path)) 103 return (0); 104 state.msg_attr.exp_from = state.msg_attr.local; 105 106 /* 107 * Can of worms. Allow this include file to be symlinked, but disallow 108 * inclusion of special files or of files with world write permission 109 * enabled. 110 */ 111 if (*path != '/') { 112 msg_warn(":include:%s uses a relative path", path); 113 dsb_simple(state.msg_attr.why, "5.3.5", 114 "mail system configuration error"); 115 return (bounce_append(BOUNCE_FLAGS(state.request), 116 BOUNCE_ATTR(state.msg_attr))); 117 } 118 if (stat_as(path, &st, usr_attr.uid, usr_attr.gid) < 0) { 119 msg_warn("unable to lookup :include: file %s: %m", path); 120 dsb_simple(state.msg_attr.why, "5.3.5", 121 "mail system configuration error"); 122 return (bounce_append(BOUNCE_FLAGS(state.request), 123 BOUNCE_ATTR(state.msg_attr))); 124 } 125 if (S_ISREG(st.st_mode) == 0) { 126 msg_warn(":include: file %s is not a regular file", path); 127 dsb_simple(state.msg_attr.why, "5.3.5", 128 "mail system configuration error"); 129 return (bounce_append(BOUNCE_FLAGS(state.request), 130 BOUNCE_ATTR(state.msg_attr))); 131 } 132 if (st.st_mode & S_IWOTH) { 133 msg_warn(":include: file %s is world writable", path); 134 dsb_simple(state.msg_attr.why, "5.3.5", 135 "mail system configuration error"); 136 return (bounce_append(BOUNCE_FLAGS(state.request), 137 BOUNCE_ATTR(state.msg_attr))); 138 } 139 140 /* 141 * DELIVERY POLICY 142 * 143 * Set the expansion type attribute so that we can decide if destinations 144 * such as /file/name and |command are allowed at all. 145 */ 146 state.msg_attr.exp_type = EXPAND_TYPE_INCL; 147 148 /* 149 * DELIVERY RIGHTS 150 * 151 * When a non-root include file is listed in a root-owned alias, use the 152 * rights of the include file owner. We do not want to give the include 153 * file owner control of the default account. 154 * 155 * When an include file is listed in a user-owned alias or .forward file, 156 * leave the delivery rights alone. Users should not be able to make 157 * things happen with someone else's rights just by including some file 158 * that is owned by their victim. 159 */ 160 if (usr_attr.uid == 0) { 161 if ((file_pwd = mypwuid(st.st_uid)) == 0) { 162 msg_warn("cannot find username for uid %ld", (long) st.st_uid); 163 msg_warn("%s: cannot find :include: file owner username", path); 164 dsb_simple(state.msg_attr.why, "4.3.5", 165 "mail system configuration error"); 166 return (defer_append(BOUNCE_FLAGS(state.request), 167 BOUNCE_ATTR(state.msg_attr))); 168 } 169 if (file_pwd->pw_uid != 0) 170 SET_USER_ATTR(usr_attr, file_pwd, state.level); 171 } 172 173 /* 174 * MESSAGE FORWARDING 175 * 176 * When no owner attribute is set (either via an owner- alias, or as part of 177 * .forward file processing), set the owner attribute, to disable direct 178 * delivery of local recipients. By now it is clear that the owner 179 * attribute should have been called forwarder instead. 180 */ 181 if (state.msg_attr.owner == 0) 182 state.msg_attr.owner = state.msg_attr.rcpt.address; 183 184 /* 185 * From here on no early returns or we have a memory leak. 186 * 187 * FILE OPEN RIGHTS 188 * 189 * Use the delivery rights to open the include file. When no delivery rights 190 * were established sofar, the file containing the :include: is owned by 191 * root, so it should be OK to open any file that is accessible to root. 192 * The command and file delivery routines are responsible for setting the 193 * proper delivery rights. These are the rights of the default user, in 194 * case the :include: is in a root-owned alias. 195 * 196 * Don't propagate unmatched extensions unless permitted to do so. 197 */ 198 #define FOPEN_AS(p,u,g) ((fd = open_as(p,O_RDONLY,0,u,g)) >= 0 ? \ 199 vstream_fdopen(fd,O_RDONLY) : 0) 200 201 if ((fp = FOPEN_AS(path, usr_attr.uid, usr_attr.gid)) == 0) { 202 msg_warn("cannot open include file %s: %m", path); 203 dsb_simple(state.msg_attr.why, "5.3.5", 204 "mail system configuration error"); 205 status = bounce_append(BOUNCE_FLAGS(state.request), 206 BOUNCE_ATTR(state.msg_attr)); 207 } else { 208 if ((local_ext_prop_mask & EXT_PROP_INCLUDE) == 0) 209 state.msg_attr.unmatched = 0; 210 close_on_exec(vstream_fileno(fp), CLOSE_ON_EXEC); 211 status = deliver_token_stream(state, usr_attr, fp, (int *) 0); 212 if (vstream_fclose(fp)) 213 msg_warn("close %s: %m", path); 214 } 215 216 /* 217 * Cleanup. 218 */ 219 if (file_pwd) 220 mypwfree(file_pwd); 221 222 return (status); 223 } 224