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author | Dag-Erling Smørgrav <des@FreeBSD.org> | 2024-07-05 22:05:49 +0000 |
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committer | Dag-Erling Smørgrav <des@FreeBSD.org> | 2024-07-05 22:05:49 +0000 |
commit | c15290fb9d8fdf4b11b9c6e7406b67c73a98402d (patch) | |
tree | 26ee12c42599315d7e2eec6d98149066b9a3cbd7 | |
parent | b81424adf7181d816c10b1345aaa3305ab0ec304 (diff) | |
download | src-c15290fb9d8fdf4b11b9c6e7406b67c73a98402d.tar.gz src-c15290fb9d8fdf4b11b9c6e7406b67c73a98402d.zip |
tftpd: Code cleanup.
MFC after: 3 days
Sponsored by: Klara, Inc.
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D45871
-rw-r--r-- | libexec/tftpd/tftpd.c | 91 |
1 files changed, 41 insertions, 50 deletions
diff --git a/libexec/tftpd/tftpd.c b/libexec/tftpd/tftpd.c index 3f67ad2920cf..a51fb4742985 100644 --- a/libexec/tftpd/tftpd.c +++ b/libexec/tftpd/tftpd.c @@ -680,28 +680,27 @@ find_next_name(char *filename, int *fd) int validate_access(int peer, char **filep, int mode) { - struct stat stbuf; - int fd; - int error; - struct dirlist *dirp; static char pathname[MAXPATHLEN]; + struct stat sb; + struct dirlist *dirp; char *filename = *filep; + int err, fd; /* * Prevent tricksters from getting around the directory restrictions */ - if (strstr(filename, "/../")) + if (strncmp(filename, "../", 3) == 0 || + strstr(filename, "/../") != NULL) return (EACCESS); if (*filename == '/') { /* - * Allow the request if it's in one of the approved locations. - * Special case: check the null prefix ("/") by looking - * for length = 1 and relying on the arg. processing that - * it's a /. + * Absolute file name: allow the request if it's in one of the + * approved locations. */ for (dirp = dirs; dirp->name != NULL; dirp++) { if (dirp->len == 1) + /* Only "/" can have len 1 */ break; if (strncmp(filename, dirp->name, dirp->len) == 0 && filename[dirp->len] == '/') @@ -710,30 +709,20 @@ validate_access(int peer, char **filep, int mode) /* If directory list is empty, allow access to any file */ if (dirp->name == NULL && dirp != dirs) return (EACCESS); - if (stat(filename, &stbuf) < 0) + if (stat(filename, &sb) != 0) return (errno == ENOENT ? ENOTFOUND : EACCESS); - if ((stbuf.st_mode & S_IFMT) != S_IFREG) + if (!S_ISREG(sb.st_mode)) return (ENOTFOUND); if (mode == RRQ) { - if ((stbuf.st_mode & S_IROTH) == 0) + if ((sb.st_mode & S_IROTH) == 0) return (EACCESS); } else { - if (check_woth && ((stbuf.st_mode & S_IWOTH) == 0)) + if (check_woth && (sb.st_mode & S_IWOTH) == 0) return (EACCESS); } } else { - int err; - /* * Relative file name: search the approved locations for it. - * Don't allow write requests that avoid directory - * restrictions. - */ - - if (!strncmp(filename, "../", 3)) - return (EACCESS); - - /* * If the file exists in one of the directories and isn't * readable, continue looking. However, change the error code * to give an indication that the file exists. @@ -741,18 +730,20 @@ validate_access(int peer, char **filep, int mode) err = ENOTFOUND; for (dirp = dirs; dirp->name != NULL; dirp++) { snprintf(pathname, sizeof(pathname), "%s/%s", - dirp->name, filename); - if (stat(pathname, &stbuf) == 0 && - (stbuf.st_mode & S_IFMT) == S_IFREG) { - if (mode == RRQ) { - if ((stbuf.st_mode & S_IROTH) != 0) - break; - } else { - if (!check_woth || ((stbuf.st_mode & S_IWOTH) != 0)) - break; - } - err = EACCESS; + dirp->name, filename); + if (stat(pathname, &sb) != 0) + continue; + if (!S_ISREG(sb.st_mode)) + continue; + err = EACCESS; + if (mode == RRQ) { + if ((sb.st_mode & S_IROTH) == 0) + continue; + } else { + if (check_woth && (sb.st_mode & S_IWOTH) == 0) + continue; } + break; } if (dirp->name != NULL) *filep = filename = pathname; @@ -766,27 +757,27 @@ validate_access(int peer, char **filep, int mode) * This option is handled here because it (might) require(s) the * size of the file. */ - option_tsize(peer, NULL, mode, &stbuf); + option_tsize(peer, NULL, mode, &sb); - if (mode == RRQ) + if (mode == RRQ) { fd = open(filename, O_RDONLY); - else { - if (create_new) { - if (increase_name) { - error = find_next_name(filename, &fd); - if (error > 0) - return (error + 100); - } else - fd = open(filename, - O_WRONLY | O_TRUNC | O_CREAT, - S_IRUSR | S_IWUSR | S_IRGRP | - S_IWGRP | S_IROTH | S_IWOTH ); - } else - fd = open(filename, O_WRONLY | O_TRUNC); + } else if (create_new) { + if (increase_name) { + err = find_next_name(filename, &fd); + if (err > 0) + return (err + 100); + } else { + fd = open(filename, + O_WRONLY | O_TRUNC | O_CREAT, + S_IRUSR | S_IWUSR | S_IRGRP | + S_IWGRP | S_IROTH | S_IWOTH ); + } + } else { + fd = open(filename, O_WRONLY | O_TRUNC); } if (fd < 0) return (errno + 100); - file = fdopen(fd, (mode == RRQ)? "r":"w"); + file = fdopen(fd, mode == RRQ ? "r" : "w"); if (file == NULL) { close(fd); return (errno + 100); |