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tftpd: fix download: we must change user AFTER bind

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tftp_protocol                                       1466    1468      +2
This commit is contained in:
Denis Vlasenko 2008-03-19 13:24:13 +00:00
parent 403a5a298e
commit 7a60133c6c
1 changed files with 42 additions and 37 deletions
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79
networking/tftp.c
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@ -83,9 +83,7 @@ enum {
struct globals {
/* u16 TFTP_ERROR; u16 reason; both network-endian, then error text: */
uint8_t error_pkt[4 + 32];
#if ENABLE_TFTPD
char *user_opt;
#endif
/* used in tftpd_main(), a bit big for stack: */
char block_buf[TFTP_BLKSIZE_DEFAULT];
};
@ -183,7 +181,7 @@ static int tftp_protocol(
int open_mode, local_fd;
int retries, waittime_ms;
int io_bufsize = blksize + 4;
char *cp;
char *cp = cp; /* for compiler */
/* Can't use RESERVE_CONFIG_BUFFER here since the allocation
* size varies meaning BUFFERS_GO_ON_STACK would fail */
/* We must keep the transmit and receive buffers seperate */
@ -194,40 +192,8 @@ static int tftp_protocol(
socket_fd = xsocket(peer_lsa->u.sa.sa_family, SOCK_DGRAM, 0);
setsockopt_reuseaddr(socket_fd);
#if ENABLE_TFTPD
if (user_opt) {
struct passwd *pw = getpwnam(user_opt); /* initgroups, setgid, setuid */
if (!pw)
bb_error_msg_and_die("unknown user '%s'", user_opt);
change_identity(pw);
}
#endif
if (CMD_PUT(option_mask32)) {
open_mode = O_RDONLY;
} else {
open_mode = O_WRONLY | O_TRUNC | O_CREAT;
#if ENABLE_TFTPD
if ((option_mask32 & (TFTPD_OPT+TFTPD_OPT_c)) == TFTPD_OPT) {
/* tftpd without -c */
open_mode = O_WRONLY | O_TRUNC;
}
#endif
}
if (!(option_mask32 & TFTPD_OPT)) {
local_fd = CMD_GET(option_mask32) ? STDOUT_FILENO : STDIN_FILENO;
if (NOT_LONE_DASH(local_file))
local_fd = xopen(local_file, open_mode);
} else {
local_fd = open_or_warn(local_file, open_mode);
if (local_fd < 0) {
/*error_pkt_reason = ERR_NOFILE/ERR_ACCESS?*/
strcpy(error_pkt_str, "can't open file");
goto send_err_pkt;
}
}
block_nr = 1;
if (!ENABLE_TFTP || our_lsa) {
/* tftpd */
@ -258,9 +224,48 @@ static int tftp_protocol(
* that is, for "block 0" which is our OACK pkt */
opcode = TFTP_OACK;
cp = xbuf + 2;
/* to be continued, see below */
}
#endif
if (user_opt) {
struct passwd *pw = getpwnam(user_opt);
if (!pw)
bb_error_msg_and_die("unknown user '%s'", user_opt);
change_identity(pw); /* initgroups, setgid, setuid */
}
}
/* Open local file (must be after changing user) */
if (CMD_PUT(option_mask32)) {
open_mode = O_RDONLY;
} else {
open_mode = O_WRONLY | O_TRUNC | O_CREAT;
#if ENABLE_TFTPD
if ((option_mask32 & (TFTPD_OPT+TFTPD_OPT_c)) == TFTPD_OPT) {
/* tftpd without -c */
open_mode = O_WRONLY | O_TRUNC;
}
#endif
}
if (!(option_mask32 & TFTPD_OPT)) {
local_fd = CMD_GET(option_mask32) ? STDOUT_FILENO : STDIN_FILENO;
if (NOT_LONE_DASH(local_file))
local_fd = xopen(local_file, open_mode);
} else {
local_fd = open_or_warn(local_file, open_mode);
if (local_fd < 0) {
/*error_pkt_reason = ERR_NOFILE/ERR_ACCESS?*/
strcpy(error_pkt_str, "can't open file");
goto send_err_pkt;
}
}
if (!ENABLE_TFTP || our_lsa) {
#if ENABLE_FEATURE_TFTP_BLOCKSIZE
if (blksize != TFTP_BLKSIZE_DEFAULT) {
/* Create and send OACK packet. continued */
goto add_blksize_opt;
}
/* else: just fall into while (1) loop below */
#endif
} else {
/* tftp */