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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:16:13 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:16:13 +0000 |
commit | e90fcc54809db2591dc083f43ef54c6ec8c60847 (patch) | |
tree | f20bc206c3c2d5d59d37c46c5cf5d53a20642556 /src/lookups/lf_check_file.c | |
parent | Initial commit. (diff) | |
download | exim4-e90fcc54809db2591dc083f43ef54c6ec8c60847.tar.xz exim4-e90fcc54809db2591dc083f43ef54c6ec8c60847.zip |
Adding upstream version 4.96.upstream/4.96upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/lookups/lf_check_file.c | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/src/lookups/lf_check_file.c b/src/lookups/lf_check_file.c new file mode 100644 index 0000000..7f0f128 --- /dev/null +++ b/src/lookups/lf_check_file.c @@ -0,0 +1,113 @@ +/************************************************* +* Exim - an Internet mail transport agent * +*************************************************/ + +/* Copyright (c) University of Cambridge 1995 - 2009 */ +/* Copyright (c) The Exim Maintainers 2020 */ +/* See the file NOTICE for conditions of use and distribution. */ + + +#include "../exim.h" +#include "lf_functions.h" + + + +/************************************************* +* Check a file's credentials * +*************************************************/ + +/* fstat can normally be expected to work on an open file, but there are some +NFS states where it may not. + +Arguments: + fd an open file descriptor or -1 + filename a file name if fd is -1 + s_type type of file (S_IFREG or S_IFDIR) + modemask a mask specifying mode bits that must *not* be set + owners NULL or a list of of allowable uids, count in the first item + owngroups NULL or a list of allowable gids, count in the first item + type name of lookup type for putting in error message + errmsg where to put an error message + +Returns: -1 stat() or fstat() failed + 0 OK + +1 something didn't match + +Side effect: sets errno to ERRNO_BADUGID, ERRNO_NOTREGULAR or ERRNO_BADMODE for + bad uid/gid, not a regular file, or bad mode; otherwise leaves it + to what fstat set it to. +*/ + +int +lf_check_file(int fd, const uschar * filename, int s_type, int modemask, + uid_t * owners, gid_t * owngroups, const char * type, uschar ** errmsg) +{ +struct stat statbuf; + +if ((fd >= 0 && fstat(fd, &statbuf) != 0) || + (fd < 0 && Ustat(filename, &statbuf) != 0)) + { + int save_errno = errno; + *errmsg = string_sprintf("%s: stat failed", filename); + errno = save_errno; + return -1; + } + +if ((statbuf.st_mode & S_IFMT) != s_type) + { + if (s_type == S_IFREG) + { + *errmsg = string_sprintf("%s is not a regular file (%s lookup)", + filename, type); + errno = ERRNO_NOTREGULAR; + } + else + { + *errmsg = string_sprintf("%s is not a directory (%s lookup)", + filename, type); + errno = ERRNO_NOTDIRECTORY; + } + return +1; + } + +if ((statbuf.st_mode & modemask) != 0) + { + *errmsg = string_sprintf("%s (%s lookup): file mode %.4o should not contain " + "%.4o", filename, type, statbuf.st_mode & 07777, + statbuf.st_mode & modemask); + errno = ERRNO_BADMODE; + return +1; + } + +if (owners != NULL) + { + BOOL uid_ok = FALSE; + for (int i = 1; i <= (int)owners[0]; i++) + if (owners[i] == statbuf.st_uid) { uid_ok = TRUE; break; } + if (!uid_ok) + { + *errmsg = string_sprintf("%s (%s lookup): file has wrong owner", filename, + type); + errno = ERRNO_BADUGID; + return +1; + } + } + +if (owngroups != NULL) + { + BOOL gid_ok = FALSE; + for (int i = 1; i <= (int)owngroups[0]; i++) + if (owngroups[i] == statbuf.st_gid) { gid_ok = TRUE; break; } + if (!gid_ok) + { + *errmsg = string_sprintf("%s (%s lookup): file has wrong group", filename, + type); + errno = ERRNO_BADUGID; + return +1; + } + } + +return 0; +} + +/* End of lf_check_file.c */ |