Currently, we put no strains on escape sequence possibly leaving users with console that cannot be terminated. However, not all ASCII characters can be used as escape sequence. Only those falling in @ - _ can be; implement and document this constraint. --- tools/console.c | 3 ++- tools/virsh.c | 13 ++++++++++++- tools/virsh.pod | 3 ++- 3 files changed, 16 insertions(+), 3 deletions(-) diff --git a/tools/console.c b/tools/console.c index ca226c3..0f30b95 100644 --- a/tools/console.c +++ b/tools/console.c @@ -34,6 +34,7 @@ # include <errno.h> # include <unistd.h> # include <signal.h> +# include <c-ctype.h> # include "internal.h" # include "console.h" @@ -292,7 +293,7 @@ static char vshGetEscapeChar(const char *s) { if (*s == '^') - return CONTROL(s[1]); + return CONTROL(c_islower(s[1]) ? c_toupper(s[1]) : s[1]); return *s; } diff --git a/tools/virsh.c b/tools/virsh.c index 1ed2dda..cfdd040 100644 --- a/tools/virsh.c +++ b/tools/virsh.c @@ -19879,6 +19879,16 @@ vshShowVersion(vshControl *ctl ATTRIBUTE_UNUSED) vshPrint(ctl, "\n"); } +static bool +vshAllowedEscapeChar(char c) +{ + /* Allowed escape characters: + * a-z A-Z @ [ \ ] ^ _ + */ + return ('a' <= c && c <= 'z') || + ('@' <= c && c <= '_'); +} + /* * argv[]: virsh [options] [command] * @@ -19942,7 +19952,8 @@ vshParseArgv(vshControl *ctl, int argc, char **argv) case 'e': len = strlen(optarg); - if ((len == 2 && *optarg == '^') || + if ((len == 2 && *optarg == '^' && + vshAllowedEscapeChar(optarg[1])) || (len == 1 && *optarg != '^')) { ctl->escapeChar = optarg; } else { diff --git a/tools/virsh.pod b/tools/virsh.pod index d4971a3..a60e667 100644 --- a/tools/virsh.pod +++ b/tools/virsh.pod @@ -95,7 +95,8 @@ Output elapsed time information for each command. =item B<-e>, B<--escape> I<string> Set alternative escape sequence for I<console> command. By default, -telnet's B<^]> is used. +telnet's B<^]> is used. Allowed characters when using hat notation are: +alphabetic character, @, [, ], \, ^, _. =back -- 1.7.8.5