5bfc4a32f
Denys Vlasenko
2019-01-06
Subject
telnet: speed up processing of network input
Binary
No binary (build failed)
Architecture & Compiler Flags
—
Build Log
(log yok)
Commit Diff GitHub →
networking/telnet.c+43 -40
| @@ -94,19 +94,19 @@ enum { | |
| IACBUFSIZE = 128, | |
| CHM_TRY = 0, | |
| - | CHM_ON = 1, |
| + | CHM_ON = 1, |
| CHM_OFF = 2, | |
| UF_ECHO = 0x01, | |
| - | UF_SGA = 0x02, |
| + | UF_SGA = 0x02, |
| TS_NORMAL = 0, | |
| TS_COPY = 1, | |
| - | TS_IAC = 2, |
| - | TS_OPT = 3, |
| + | TS_IAC = 2, |
| + | TS_OPT = 3, |
| TS_SUB1 = 4, | |
| TS_SUB2 = 5, | |
| - | TS_CR = 6, |
| + | TS_CR = 6, |
| }; | |
| typedef unsigned char byte; | |
| @@ -244,25 +244,34 @@ static void handle_net_output(int len) | |
| static void handle_net_input(int len) | |
| { | |
| + | byte c; |
| int i; | |
| - | int cstart = 0; |
| - | |
| - | for (i = 0; i < len; i++) { |
| - | byte c = G.buf[i]; |
| - | |
| - | if (G.telstate == TS_NORMAL) { /* most typical state */ |
| - | if (c == IAC) { |
| - | cstart = i; |
| - | G.telstate = TS_IAC; |
| - | } |
| - | else if (c == '\r') { |
| - | cstart = i + 1; |
| - | G.telstate = TS_CR; |
| - | } |
| - | /* No IACs were seen so far, no need to copy |
| - | * bytes within G.buf: */ |
| - | continue; |
| + | int cstart; |
| + | |
| + | i = 0; |
| + | //bb_error_msg("[%u,'%.*s']", G.telstate, len, G.buf); |
| + | if (G.telstate == TS_NORMAL) { /* most typical state */ |
| + | while (i < len) { |
| + | c = G.buf[i]; |
| + | i++; |
| + | if (c == IAC) /* unlikely */ |
| + | goto got_IAC; |
| + | if (c != '\r') /* likely */ |
| + | continue; |
| + | G.telstate = TS_CR; |
| + | cstart = i; |
| + | goto got_special; |
| } | |
| + | full_write(STDOUT_FILENO, G.buf, len); |
| + | return; |
| + | got_IAC: |
| + | G.telstate = TS_IAC; |
| + | cstart = i - 1; |
| + | got_special: ; |
| + | } |
| + | |
| + | for (; i < len; i++) { |
| + | c = G.buf[i]; |
| switch (G.telstate) { | |
| case TS_CR: | |
| @@ -278,20 +287,19 @@ static void handle_net_input(int len) | |
| /* Similar to NORMAL, but in TS_COPY we need to copy bytes */ | |
| if (c == IAC) | |
| G.telstate = TS_IAC; | |
| - | else |
| + | else { |
| G.buf[cstart++] = c; | |
| - | if (c == '\r') |
| - | G.telstate = TS_CR; |
| + | if (c == '\r') |
| + | G.telstate = TS_CR; |
| + | } |
| break; | |
| case TS_IAC: /* Prev char was IAC */ | |
| - | if (c == IAC) { /* IAC IAC -> one IAC */ |
| + | switch (c) { |
| + | case IAC: /* IAC IAC -> one IAC */ |
| G.buf[cstart++] = c; | |
| G.telstate = TS_COPY; | |
| break; | |
| - | } |
| - | /* else */ |
| - | switch (c) { |
| case SB: | |
| G.telstate = TS_SUB1; | |
| break; | |
| @@ -320,17 +328,12 @@ static void handle_net_input(int len) | |
| } | |
| } | |
| - | if (G.telstate != TS_NORMAL) { |
| - | /* We had some IACs, or CR */ |
| - | if (G.iaclen) |
| - | iac_flush(); |
| - | if (G.telstate == TS_COPY) /* we aren't in the middle of IAC */ |
| - | G.telstate = TS_NORMAL; |
| - | len = cstart; |
| - | } |
| - | |
| - | if (len) |
| - | full_write(STDOUT_FILENO, G.buf, len); |
| + | /* We had some IACs, or CR */ |
| + | iac_flush(); |
| + | if (G.telstate == TS_COPY) /* we aren't in the middle of IAC */ |
| + | G.telstate = TS_NORMAL; |
| + | if (cstart != 0) |
| + | full_write(STDOUT_FILENO, G.buf, cstart); |
| } | |
| static void put_iac(int c) | |