tftpd: fix -u USER to work with chroot. Closes 5348

function                                             old     new   delta
tftpd_main                                           546     568     +22
tftp_protocol                                       1844    1839      -5

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2012-07-18 17:32:32 +02:00
parent df8066a78c
commit dbed6c4b46

View File

@ -116,7 +116,7 @@ enum {
struct globals {
/* u16 TFTP_ERROR; u16 reason; both network-endian, then error text: */
uint8_t error_pkt[4 + 32];
char *user_opt;
struct passwd *pw;
/* used in tftpd_main(), a bit big for stack: */
char block_buf[TFTP_BLKSIZE_DEFAULT];
#if ENABLE_FEATURE_TFTP_PROGRESS_BAR
@ -130,13 +130,10 @@ struct globals {
struct BUG_G_too_big {
char BUG_G_too_big[sizeof(G) <= COMMON_BUFSIZE ? 1 : -1];
};
#define block_buf (G.block_buf )
#define user_opt (G.user_opt )
#define error_pkt (G.error_pkt )
#define INIT_G() do { } while (0)
#define error_pkt_reason (error_pkt[3])
#define error_pkt_str (error_pkt + 4)
#define G_error_pkt_reason (G.error_pkt[3])
#define G_error_pkt_str ((char*)(G.error_pkt + 4))
#if ENABLE_FEATURE_TFTP_PROGRESS_BAR
static void tftp_progress_update(void)
@ -272,12 +269,11 @@ static int tftp_protocol(
xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len);
/* Is there an error already? Send pkt and bail out */
if (error_pkt_reason || error_pkt_str[0])
if (G_error_pkt_reason || G_error_pkt_str[0])
goto send_err_pkt;
if (user_opt) {
struct passwd *pw = xgetpwnam(user_opt);
change_identity(pw); /* initgroups, setgid, setuid */
if (G.pw) {
change_identity(G.pw); /* initgroups, setgid, setuid */
}
}
@ -329,8 +325,8 @@ static int tftp_protocol(
/* Open file (must be after changing user) */
local_fd = open(local_file, open_mode, 0666);
if (local_fd < 0) {
error_pkt_reason = ERR_NOFILE;
strcpy((char*)error_pkt_str, "can't open file");
G_error_pkt_reason = ERR_NOFILE;
strcpy(G_error_pkt_str, "can't open file");
goto send_err_pkt;
}
/* gcc 4.3.1 would NOT optimize it out as it should! */
@ -575,7 +571,7 @@ static int tftp_protocol(
if (res) {
blksize = tftp_blksize_check(res, blksize);
if (blksize < 0) {
error_pkt_reason = ERR_BAD_OPT;
G_error_pkt_reason = ERR_BAD_OPT;
goto send_err_pkt;
}
io_bufsize = blksize + 4;
@ -614,8 +610,8 @@ static int tftp_protocol(
if (recv_blk == block_nr) {
int sz = full_write(local_fd, &rbuf[4], len - 4);
if (sz != len - 4) {
strcpy((char*)error_pkt_str, bb_msg_write_error);
error_pkt_reason = ERR_WRITE;
strcpy(G_error_pkt_str, bb_msg_write_error);
G_error_pkt_reason = ERR_WRITE;
goto send_err_pkt;
}
if (sz != blksize) {
@ -664,12 +660,12 @@ static int tftp_protocol(
return finished == 0; /* returns 1 on failure */
send_read_err_pkt:
strcpy((char*)error_pkt_str, bb_msg_read_error);
strcpy(G_error_pkt_str, bb_msg_read_error);
send_err_pkt:
if (error_pkt_str[0])
bb_error_msg("%s", (char*)error_pkt_str);
error_pkt[1] = TFTP_ERROR;
xsendto(socket_fd, error_pkt, 4 + 1 + strlen((char*)error_pkt_str),
if (G_error_pkt_str[0])
bb_error_msg("%s", G_error_pkt_str);
G.error_pkt[1] = TFTP_ERROR;
xsendto(socket_fd, G.error_pkt, 4 + 1 + strlen(G_error_pkt_str),
&peer_lsa->u.sa, peer_lsa->len);
return EXIT_FAILURE;
#undef remote_file
@ -761,7 +757,7 @@ int tftpd_main(int argc UNUSED_PARAM, char **argv)
{
len_and_sockaddr *our_lsa;
len_and_sockaddr *peer_lsa;
char *local_file, *mode;
char *local_file, *mode, *user_opt;
const char *error_msg;
int opt, result, opcode;
IF_FEATURE_TFTP_BLOCKSIZE(int blksize = TFTP_BLKSIZE_DEFAULT;)
@ -789,18 +785,22 @@ int tftpd_main(int argc UNUSED_PARAM, char **argv)
openlog(applet_name, LOG_PID, LOG_DAEMON);
logmode = LOGMODE_SYSLOG;
}
if (opt & TFTPD_OPT_u) {
/* Must be before xchroot */
G.pw = xgetpwnam(user_opt);
}
if (argv[0]) {
xchroot(argv[0]);
}
result = recv_from_to(STDIN_FILENO, block_buf, sizeof(block_buf),
result = recv_from_to(STDIN_FILENO, G.block_buf, sizeof(G.block_buf),
0 /* flags */,
&peer_lsa->u.sa, &our_lsa->u.sa, our_lsa->len);
error_msg = "malformed packet";
opcode = ntohs(*(uint16_t*)block_buf);
if (result < 4 || result >= sizeof(block_buf)
|| block_buf[result-1] != '\0'
opcode = ntohs(*(uint16_t*)G.block_buf);
if (result < 4 || result >= sizeof(G.block_buf)
|| G.block_buf[result-1] != '\0'
|| (IF_FEATURE_TFTP_PUT(opcode != TFTP_RRQ) /* not download */
IF_GETPUT(&&)
IF_FEATURE_TFTP_GET(opcode != TFTP_WRQ) /* not upload */
@ -808,27 +808,27 @@ int tftpd_main(int argc UNUSED_PARAM, char **argv)
) {
goto err;
}
local_file = block_buf + 2;
local_file = G.block_buf + 2;
if (local_file[0] == '.' || strstr(local_file, "/.")) {
error_msg = "dot in file name";
goto err;
}
mode = local_file + strlen(local_file) + 1;
/* RFC 1350 says mode string is case independent */
if (mode >= block_buf + result || strcasecmp(mode, "octet") != 0) {
if (mode >= G.block_buf + result || strcasecmp(mode, "octet") != 0) {
goto err;
}
# if ENABLE_FEATURE_TFTP_BLOCKSIZE
{
char *res;
char *opt_str = mode + sizeof("octet");
int opt_len = block_buf + result - opt_str;
int opt_len = G.block_buf + result - opt_str;
if (opt_len > 0) {
res = tftp_get_option("blksize", opt_str, opt_len);
if (res) {
blksize = tftp_blksize_check(res, 65564);
if (blksize < 0) {
error_pkt_reason = ERR_BAD_OPT;
G_error_pkt_reason = ERR_BAD_OPT;
/* will just send error pkt */
goto do_proto;
}
@ -846,7 +846,7 @@ int tftpd_main(int argc UNUSED_PARAM, char **argv)
if (!ENABLE_FEATURE_TFTP_PUT || opcode == TFTP_WRQ) {
if (opt & TFTPD_OPT_r) {
/* This would mean "disk full" - not true */
/*error_pkt_reason = ERR_WRITE;*/
/*G_error_pkt_reason = ERR_WRITE;*/
error_msg = bb_msg_write_error;
goto err;
}
@ -855,7 +855,7 @@ int tftpd_main(int argc UNUSED_PARAM, char **argv)
IF_GETPUT(option_mask32 |= TFTP_OPT_PUT;) /* will send file's data */
}
/* NB: if error_pkt_str or error_pkt_reason is set up,
/* NB: if G_error_pkt_str or G_error_pkt_reason is set up,
* tftp_protocol() just sends one error pkt and returns */
do_proto:
@ -870,7 +870,7 @@ int tftpd_main(int argc UNUSED_PARAM, char **argv)
return result;
err:
strcpy((char*)error_pkt_str, error_msg);
strcpy(G_error_pkt_str, error_msg);
goto do_proto;
}