Mercurial > dropbear
changeset 726:78eda530c000
send out our kexinit packet before blocking to read the SSH version string
| author | Matt Johnston <matt@ucc.asn.au> |
|---|---|
| date | Sun, 31 Mar 2013 00:40:00 +0800 |
| parents | 49f68a7b7a55 |
| children | 00bc3df3a9c3 cd201dc2da9a |
| files | cli-session.c common-session.c session.h svr-session.c |
| diffstat | 4 files changed, 26 insertions(+), 14 deletions(-) [+] |
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--- a/cli-session.c Sun Mar 24 00:02:20 2013 +0800 +++ b/cli-session.c Sun Mar 31 00:40:00 2013 +0800 @@ -99,7 +99,7 @@ sessinitdone = 1; /* Exchange identification */ - session_identification(); + send_session_identification(); send_msg_kexinit();
--- a/common-session.c Sun Mar 24 00:02:20 2013 +0800 +++ b/common-session.c Sun Mar 31 00:40:00 2013 +0800 @@ -39,6 +39,7 @@ static void checktimeouts(); static long select_timeout(); static int ident_readln(int fd, char* buf, int count); +static void read_session_identification(); struct sshsession ses; /* GLOBAL */ @@ -141,7 +142,10 @@ FD_ZERO(&writefd); FD_ZERO(&readfd); dropbear_assert(ses.payload == NULL); - if (ses.sock_in != -1) { + + /* during initial setup we flush out the KEXINIT packet before + * attempting to read the remote version string, which might block */ + if (ses.sock_in != -1 && (ses.remoteident || isempty(&ses.writequeue))) { FD_SET(ses.sock_in, &readfd); } if (ses.sock_out != -1 && !isempty(&ses.writequeue)) { @@ -195,7 +199,12 @@ if (ses.sock_in != -1) { if (FD_ISSET(ses.sock_in, &readfd)) { - read_packet(); + if (!ses.remoteident) { + /* blocking read of the version string */ + read_session_identification(); + } else { + read_packet(); + } } /* Process the decrypted packet. After this, the read buffer @@ -245,20 +254,20 @@ } -void session_identification() { +void send_session_identification() { + /* write our version string, this blocks */ + if (atomicio(write, ses.sock_out, LOCAL_IDENT "\r\n", + strlen(LOCAL_IDENT "\r\n")) == DROPBEAR_FAILURE) { + ses.remoteclosed(); + } +} +static void read_session_identification() { /* max length of 255 chars */ char linebuf[256]; int len = 0; char done = 0; int i; - - /* write our version string, this blocks */ - if (atomicio(write, ses.sock_out, LOCAL_IDENT "\r\n", - strlen(LOCAL_IDENT "\r\n")) == DROPBEAR_FAILURE) { - ses.remoteclosed(); - } - /* If they send more than 50 lines, something is wrong */ for (i = 0; i < 50; i++) { len = ident_readln(ses.sock_in, linebuf, sizeof(linebuf));
--- a/session.h Sun Mar 24 00:02:20 2013 +0800 +++ b/session.h Sun Mar 31 00:40:00 2013 +0800 @@ -45,7 +45,7 @@ void common_session_init(int sock_in, int sock_out); void session_loop(void(*loophandler)()); void common_session_cleanup(); -void session_identification(); +void send_session_identification(); void send_msg_ignore(); const char* get_user_shell(); @@ -111,7 +111,10 @@ int sock_in; int sock_out; - unsigned char *remoteident; + /* remotehost will be initially NULL as we delay + * reading the remote version string. it will be set + * by the time any recv_() packet methods are called */ + unsigned char *remoteident; int maxfd; /* the maximum file descriptor to check with select() */