Fall back to sane filename instead of bailing out

This commit is contained in:
Joseph C. Lehner 2016-02-05 14:11:52 +02:00
parent ea850215ab
commit d3dfcc954d

49
tftp.c
View file

@ -40,9 +40,9 @@ enum tftp_opcode {
ERR = 5
};
static char *x_basename(const char *path)
static const char *x_basename(const char *path)
{
char *slash, *bslash;
const char *slash, *bslash;
slash = rindex(path, '/');
bslash = rindex(path, '\\');
@ -55,20 +55,18 @@ static char *x_basename(const char *path)
path = 1 + bslash;
}
return strdup(path);
return path;
}
static const char *sanitize_netascii(char *str)
static bool is_netascii(const char *str)
{
char *p = str;
for (; *p; ++p) {
if (*p < 0x20 || *p > 0x7f) {
*p = '_';
for (; *str; ++str) {
if (*str < 0x20 || *str > 0x7f) {
return false;
}
}
return str;
return true;
}
static inline void pkt_mknum(char *pkt, uint16_t n)
@ -81,16 +79,21 @@ static inline uint16_t pkt_num(char *pkt)
return ntohs(*(uint16_t*)pkt);
}
static void pkt_mkwrq(char *pkt, const char *filename, const char *mode)
static void pkt_mkwrq(char *pkt, const char *filename)
{
size_t len = 2;
filename = x_basename(filename);
if (!is_netascii(filename) || strlen(filename) > 500) {
fprintf(stderr, "Overlong/illegal filename; using 'firmware.bin'.");
filename = "firmware.bin";
}
pkt_mknum(pkt, WRQ);
strcpy(pkt + len, filename);
len += strlen(filename) + 1;
strcpy(pkt + len, mode);
len += strlen(mode) + 1;
strcpy(pkt + len, "octet");
}
static inline void pkt_print(char *pkt, FILE *fp)
@ -191,14 +194,12 @@ int sock_set_rx_timeout(int fd, unsigned msec)
int tftp_put(struct nmrpd_args *args)
{
struct sockaddr_in addr;
char *filename;
uint16_t block;
ssize_t len;
int fd, sock, err, timeout, last_len;
char rx[TFTP_PKT_SIZE], tx[TFTP_PKT_SIZE];
sock = -1;
filename = NULL;
fd = open(args->filename, O_RDONLY);
if (fd < 0) {
@ -227,21 +228,7 @@ int tftp_put(struct nmrpd_args *args)
addr.sin_family = AF_INET;
addr.sin_port = htons(args->port);
filename = x_basename(args->filename);
if (!filename) {
perror("x_basename");
goto cleanup;
} else if (strlen(filename) > 256) {
fprintf(stderr, "Filename exceeds maximum of 256 characters.\n");
goto cleanup;
}
sanitize_netascii(filename);
if (verbosity > 1) {
printf("%s -> %s\n", args->filename, filename);
}
pkt_mkwrq(tx, filename, "octet");
pkt_mkwrq(tx, args->filename);
len = tftp_sendto(sock, tx, 0, &addr);
if (len < 0) {
@ -307,8 +294,6 @@ int tftp_put(struct nmrpd_args *args)
err = 0;
cleanup:
free(filename);
if (fd >= 0) {
close(fd);
}