diff options
author | Daniel Stenberg <daniel@haxx.se> | 2023-02-23 18:14:35 +0100 |
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committer | Daniel Stenberg <daniel@haxx.se> | 2023-02-24 16:45:42 +0100 |
commit | 0c28ba2faae2d7da780a66d2446045a560192cdc (patch) | |
tree | 9a7d3ee4163f3248d29ad1b7019f4e99e9e6fd8a | |
parent | 304b5183fda43b5c5bef4008453db30fa688b10e (diff) | |
download | curl-0c28ba2faae2d7da780a66d2446045a560192cdc.tar.gz |
telnet: parse telnet options without sscanf
Closes #10596
-rw-r--r-- | lib/telnet.c | 136 |
1 files changed, 77 insertions, 59 deletions
diff --git a/lib/telnet.c b/lib/telnet.c index a964bfdcd..0c1671d0f 100644 --- a/lib/telnet.c +++ b/lib/telnet.c @@ -774,18 +774,15 @@ static CURLcode check_telnet_options(struct Curl_easy *data) { struct curl_slist *head; struct curl_slist *beg; - char option_keyword[128] = ""; - char option_arg[256] = ""; struct TELNET *tn = data->req.p.telnet; - struct connectdata *conn = data->conn; CURLcode result = CURLE_OK; - int binary_option; /* Add the user name as an environment variable if it was given on the command line */ if(data->state.aptr.user) { - msnprintf(option_arg, sizeof(option_arg), "USER,%s", conn->user); - beg = curl_slist_append(tn->telnet_vars, option_arg); + char buffer[256]; + msnprintf(buffer, sizeof(buffer), "USER,%s", data->conn->user); + beg = curl_slist_append(tn->telnet_vars, buffer); if(!beg) { curl_slist_free_all(tn->telnet_vars); tn->telnet_vars = NULL; @@ -795,68 +792,89 @@ static CURLcode check_telnet_options(struct Curl_easy *data) tn->us_preferred[CURL_TELOPT_NEW_ENVIRON] = CURL_YES; } - for(head = data->set.telnet_options; head; head = head->next) { - if(sscanf(head->data, "%127[^= ]%*[ =]%255s", - option_keyword, option_arg) == 2) { - - /* Terminal type */ - if(strcasecompare(option_keyword, "TTYPE")) { - strncpy(tn->subopt_ttype, option_arg, 31); - tn->subopt_ttype[31] = 0; /* String termination */ - tn->us_preferred[CURL_TELOPT_TTYPE] = CURL_YES; - continue; - } + for(head = data->set.telnet_options; head && !result; head = head->next) { + size_t olen; + char *option = head->data; + char *arg; + char *sep = strchr(option, '='); + if(sep) { + olen = sep - option; + arg = ++sep; + switch(olen) { + case 5: + /* Terminal type */ + if(strncasecompare(option, "TTYPE", 5)) { + strncpy(tn->subopt_ttype, arg, 31); + tn->subopt_ttype[31] = 0; /* String termination */ + tn->us_preferred[CURL_TELOPT_TTYPE] = CURL_YES; + } + else + result = CURLE_UNKNOWN_OPTION; + break; - /* Display variable */ - if(strcasecompare(option_keyword, "XDISPLOC")) { - strncpy(tn->subopt_xdisploc, option_arg, 127); - tn->subopt_xdisploc[127] = 0; /* String termination */ - tn->us_preferred[CURL_TELOPT_XDISPLOC] = CURL_YES; - continue; - } + case 8: + /* Display variable */ + if(strncasecompare(option, "XDISPLOC", 8)) { + strncpy(tn->subopt_xdisploc, arg, 127); + tn->subopt_xdisploc[127] = 0; /* String termination */ + tn->us_preferred[CURL_TELOPT_XDISPLOC] = CURL_YES; + } + else + result = CURLE_UNKNOWN_OPTION; + break; - /* Environment variable */ - if(strcasecompare(option_keyword, "NEW_ENV")) { - beg = curl_slist_append(tn->telnet_vars, option_arg); - if(!beg) { - result = CURLE_OUT_OF_MEMORY; - break; + case 7: + /* Environment variable */ + if(strncasecompare(option, "NEW_ENV", 7)) { + beg = curl_slist_append(tn->telnet_vars, arg); + if(!beg) { + result = CURLE_OUT_OF_MEMORY; + break; + } + tn->telnet_vars = beg; + tn->us_preferred[CURL_TELOPT_NEW_ENVIRON] = CURL_YES; } - tn->telnet_vars = beg; - tn->us_preferred[CURL_TELOPT_NEW_ENVIRON] = CURL_YES; - continue; - } + else + result = CURLE_UNKNOWN_OPTION; + break; - /* Window Size */ - if(strcasecompare(option_keyword, "WS")) { - if(sscanf(option_arg, "%hu%*[xX]%hu", - &tn->subopt_wsx, &tn->subopt_wsy) == 2) - tn->us_preferred[CURL_TELOPT_NAWS] = CURL_YES; - else { - failf(data, "Syntax error in telnet option: %s", head->data); - result = CURLE_SETOPT_OPTION_SYNTAX; - break; + case 2: + /* Window Size */ + if(strncasecompare(option, "WS", 2)) { + if(sscanf(arg, "%hu%*[xX]%hu", + &tn->subopt_wsx, &tn->subopt_wsy) == 2) + tn->us_preferred[CURL_TELOPT_NAWS] = CURL_YES; + else { + failf(data, "Syntax error in telnet option: %s", head->data); + result = CURLE_SETOPT_OPTION_SYNTAX; + } } - continue; - } + else + result = CURLE_UNKNOWN_OPTION; + break; - /* To take care or not of the 8th bit in data exchange */ - if(strcasecompare(option_keyword, "BINARY")) { - binary_option = atoi(option_arg); - if(binary_option != 1) { - tn->us_preferred[CURL_TELOPT_BINARY] = CURL_NO; - tn->him_preferred[CURL_TELOPT_BINARY] = CURL_NO; + case 6: + /* To take care or not of the 8th bit in data exchange */ + if(strncasecompare(option, "BINARY", 6)) { + int binary_option = atoi(arg); + if(binary_option != 1) { + tn->us_preferred[CURL_TELOPT_BINARY] = CURL_NO; + tn->him_preferred[CURL_TELOPT_BINARY] = CURL_NO; + } } - continue; + else + result = CURLE_UNKNOWN_OPTION; + break; + default: + failf(data, "Unknown telnet option %s", head->data); + result = CURLE_UNKNOWN_OPTION; + break; } - - failf(data, "Unknown telnet option %s", head->data); - result = CURLE_UNKNOWN_OPTION; - break; } - failf(data, "Syntax error in telnet option: %s", head->data); - result = CURLE_SETOPT_OPTION_SYNTAX; - break; + else { + failf(data, "Syntax error in telnet option: %s", head->data); + result = CURLE_SETOPT_OPTION_SYNTAX; + } } if(result) { |