Skip to content

Commit

Permalink
scsi-scstd: Check initiator name provided during login
Browse files Browse the repository at this point in the history 
The iSCSI specification has rules wrt what constitutes  a valid initiator
name.  Perform some checks and reject LOGINs with an invalid initiator
name.
  • Loading branch information
@bmeagherix
bmeagherix committed May 5, 2023
1 parent 3dad1e9 commit c59e33d
Show file tree
Hide file tree
Showing 2 changed files with 292 additions and 0 deletions.
1 change: 1 addition & 0 deletions iscsi-scst/include/iscsi_scst.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -70,6 +70,7 @@ static inline void set_fs(mm_segment_t seg) { }
#include "iscsi_scst_itf_ver.h"

/* The maximum length of 223 bytes in the RFC. */
#define ISCSI_NAME_CHECK_LEN 223 /* Checked during LOGIN */
#define ISCSI_NAME_LEN 256

#define ISCSI_PORTAL_LEN 64
Expand Down
291 changes: 291 additions & 0 deletions iscsi-scst/usr/iscsid.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -498,6 +498,292 @@ static int init_conn_session_params(struct connection *conn)
return res;
}

static bool valid_ascii_name_char(char ch)
{

/*
* From rtf3722
*
* For those using only ASCII characters (U+0000 to U+007F), the
* following characters are allowed:
*
* - ASCII dash character ('-' = U+002d)
* - ASCII dot character ('.' = U+002e)
* - ASCII colon character (':' = U+003a)
* - ASCII lower-case characters ('a'..'z' = U+0061..U+007a)
* - ASCII digit characters ('0'..'9' = U+0030..U+0039)
*/

if ((ch == '-') || (ch == '.') || (ch == ':') ||
((ch >= 'a') && (ch <= 'z')) ||
((ch >= '0') && (ch <= '9')))
return true;

log_error("Name contains invalid character: %c", ch);
return false;
}

static bool valid_utf8_name_char(long ch)
{
/*
* From rfc3722 6. Prohibited Output
*
* This profile specifies prohibiting using the following tables from
* [RFC3454]. Characters appearing within these tables MUST NOT be used
* within an iSCSI name.
*
* Table C.1.1
* Table C.1.2
* Table C.2.1
* Table C.2.2
* Table C.3
* Table C.4
* Table C.5
* Table C.6
* Table C.7
* Table C.8
* Table C.9
*/

/* C.1.1 ASCII space characters */
if (ch == 0x0020) {
log_error("Invalid UTF-8: %lX (ASCII space characters)", ch);
return false;
}

/* C.1.2 Non-ASCII space characters */
switch (ch) {
case 0x00A0: /* NO-BREAK SPACE */
case 0x1680: /* OGHAM SPACE MARK */
case 0x2000: /* EN QUAD */
case 0x2001: /* EM QUAD */
case 0x2002: /* EN SPACE */
case 0x2003: /* EM SPACE */
case 0x2004: /* THREE-PER-EM SPACE */
case 0x2005: /* FOUR-PER-EM SPACE */
case 0x2006: /* SIX-PER-EM SPACE */
case 0x2007: /* FIGURE SPACE */
case 0x2008: /* PUNCTUATION SPACE */
case 0x2009: /* THIN SPACE */
case 0x200A: /* HAIR SPACE */
case 0x200B: /* ZERO WIDTH SPACE */
case 0x202F: /* NARROW NO-BREAK SPACE */
case 0x205F: /* MEDIUM MATHEMATICAL SPACE */
case 0x3000: /* IDEOGRAPHIC SPACE */
log_error("Invalid UTF-8: %lX (Non-ASCII space characters)", ch);
return false;
}

/* C.2.1 ASCII control characters */
if ((ch >= 0x0000 && ch <= 0x001F) || /* CONTROL CHARACTERS */
(ch == 0x007F)) { /* DELETE */
log_error("Invalid UTF-8: %lX (ASCII control characters)", ch);
return false;
}

/* C.2.2 Non-ASCII control characters */
if ((ch >= 0x0080 && ch <= 0x009F) || /* CONTROL CHARACTERS */
(ch == 0x06DD) || /* ARABIC END OF AYAH */
(ch == 0x070F) || /* SYRIAC ABBREVIATION MARK */
(ch == 0x180E) || /* MONGOLIAN VOWEL SEPARATOR */
(ch == 0x200C) || /* ZERO WIDTH NON-JOINER */
(ch == 0x200D) || /* ZERO WIDTH JOINER */
(ch == 0x2028) || /* LINE SEPARATOR */
(ch == 0x2029) || /* PARAGRAPH SEPARATOR */
(ch == 0x2060) || /* WORD JOINER */
(ch == 0x2061) || /* FUNCTION APPLICATION */
(ch == 0x2062) || /* INVISIBLE TIMES */
(ch == 0x2063) || /* INVISIBLE SEPARATOR */
(ch >= 0x206A && (ch <= 0x206F)) || /* [CONTROL CHARACTERS] */
(ch == 0xFEFF) || /* ZERO WIDTH NO-BREAK SPACE */
(ch >= 0xFFF9 && ch <= 0xFFFC) || /* [CONTROL CHARACTERS] */
(ch >= 0x1D173 && ch <= 0x1D17A)) { /* [MUSICAL CONTROL CHARACTERS] */
log_error("Invalid UTF-8: %lX (Non-ASCII control characters)", ch);
return false;
}

/* C.3 Private use */
if ((ch >= 0xE000 && ch <= 0xF8FF) || /* [PRIVATE USE, PLANE 0] */
(ch >= 0xF0000 && ch <= 0xFFFFD) || /* [PRIVATE USE, PLANE 15] */
(ch >= 0x100000 && ch <= 0x10FFFD)) { /* [PRIVATE USE, PLANE 16] */
log_error("Invalid UTF-8: %lX (Private use)", ch);
return false;
}

/* C.4 Non-character code points */
if ((ch >= 0xFDD0 && ch <= 0xFDEF) || /* [NONCHARACTER CODE POINTS] */
(ch >= 0xFFFE && ch <= 0xFFFF) || /* [NONCHARACTER CODE POINTS] */
(ch >= 0x1FFFE && ch <= 0x1FFFF) || /* [NONCHARACTER CODE POINTS] */
(ch >= 0x2FFFE && ch <= 0x2FFFF) || /* [NONCHARACTER CODE POINTS] */
(ch >= 0x3FFFE && ch <= 0x3FFFF) || /* [NONCHARACTER CODE POINTS] */
(ch >= 0x4FFFE && ch <= 0x4FFFF) || /* [NONCHARACTER CODE POINTS] */
(ch >= 0x5FFFE && ch <= 0x5FFFF) || /* [NONCHARACTER CODE POINTS] */
(ch >= 0x6FFFE && ch <= 0x6FFFF) || /* [NONCHARACTER CODE POINTS] */
(ch >= 0x7FFFE && ch <= 0x7FFFF) || /* [NONCHARACTER CODE POINTS] */
(ch >= 0x8FFFE && ch <= 0x8FFFF) || /* [NONCHARACTER CODE POINTS] */
(ch >= 0x9FFFE && ch <= 0x9FFFF) || /* [NONCHARACTER CODE POINTS] */
(ch >= 0xAFFFE && ch <= 0xAFFFF) || /* [NONCHARACTER CODE POINTS] */
(ch >= 0xBFFFE && ch <= 0xBFFFF) || /* [NONCHARACTER CODE POINTS] */
(ch >= 0xCFFFE && ch <= 0xCFFFF) || /* [NONCHARACTER CODE POINTS] */
(ch >= 0xDFFFE && ch <= 0xDFFFF) || /* [NONCHARACTER CODE POINTS] */
(ch >= 0xEFFFE && ch <= 0xEFFFF) || /* [NONCHARACTER CODE POINTS] */
(ch >= 0xFFFFE && ch <= 0xFFFFF) || /* [NONCHARACTER CODE POINTS] */
(ch >= 0x10FFFE && ch <= 0x10FFFF)) { /* [NONCHARACTER CODE POINTS] */
log_error("Invalid UTF-8: %lX (Non-character code points)", ch);
return false;
}

/* C.5 Surrogate codes */
if (ch >= 0xD800 && ch <= 0xDFFF) { /* [SURROGATE CODES] */
log_error("Invalid UTF-8: %lX (Surrogate codes)", ch);
return false;
}

/* C.6 Inappropriate for plain text */
if ((ch == 0xFFF9) || /* INTERLINEAR ANNOTATION ANCHOR */
(ch == 0xFFFA) || /* INTERLINEAR ANNOTATION SEPARATOR */
(ch == 0xFFFB) || /* INTERLINEAR ANNOTATION TERMINATOR */
(ch == 0xFFFC) || /* OBJECT REPLACEMENT CHARACTER */
(ch == 0xFFFD)) { /* REPLACEMENT CHARACTER */
log_error("Invalid UTF-8: %lX (Inappropriate for plain text)", ch);
return false;
}

/* C.7 Inappropriate for canonical representation */
if (ch >= 0x2FF0 && ch <= 0x2FFB) { /* [IDEOGRAPHIC DESCRIPTION CHARACTERS] */
log_error("Invalid UTF-8: %lX (Inappropriate for canonical representation)", ch);
return false;
}

/* C.8 Change display properties or are deprecated */
switch (ch) {
case 0x0340: /* COMBINING GRAVE TONE MARK */
case 0x0341: /* COMBINING ACUTE TONE MARK */
case 0x200E: /* LEFT-TO-RIGHT MARK */
case 0x200F: /* RIGHT-TO-LEFT MARK */
case 0x202A: /* LEFT-TO-RIGHT EMBEDDING */
case 0x202B: /* RIGHT-TO-LEFT EMBEDDING */
case 0x202C: /* POP DIRECTIONAL FORMATTING */
case 0x202D: /* LEFT-TO-RIGHT OVERRIDE */
case 0x202E: /* RIGHT-TO-LEFT OVERRIDE */
case 0x206A: /* INHIBIT SYMMETRIC SWAPPING */
case 0x206B: /* ACTIVATE SYMMETRIC SWAPPING */
case 0x206C: /* INHIBIT ARABIC FORM SHAPING */
case 0x206D: /* ACTIVATE ARABIC FORM SHAPING */
case 0x206E: /* NATIONAL DIGIT SHAPES */
case 0x206F: /* NOMINAL DIGIT SHAPES */
log_error("Invalid UTF-8: %lX (Change display properties or are deprecated)", ch);
return false;
}

/* C.9 Tagging characters */
if ((ch == 0xE0001) || /* LANGUAGE TAG */
(ch >= 0xE0020 && ch <= 0xE007F)) { /* [TAGGING CHARACTERS] */
log_error("Invalid UTF-8: %lX (Tagging characters)", ch);
return false;
}

return true;
}

/*
* Checks whether the supplied name contains valid characters per RFC, returns true if so.
*
* It does NOT perform other formatting checks, e.g. that string starts with "iqn.",
* "naa." or "eui." ... along with subsequent formatting.
*/
static bool name_chars_are_valid(const char *name)
{
const unsigned char *bytes = (const unsigned char *)name;

if (!name)
return false;

/*
* rfc7143 4.2.7.1. iSCSI Name Properties
*
* Initiators and targets MUST support the receipt of iSCSI names of up
* to the maximum length of 223 bytes.
*/
if (strlen(name) > ISCSI_NAME_CHECK_LEN) {
log_error("Name is too long: %s (%zu)", name, strlen(name));
return false;
}

/*
* Iterate over each character in the string, validating that it is
* an accepable character. This is complicated somewhat as UTF-8
* encoding is supported.
*
* From rtf3629
* Char. number range | UTF-8 octet sequence
* (hexadecimal) | (binary)
* --------------------+---------------------------------------------
* 0000 0000-0000 007F | 0xxxxxxx
* 0000 0080-0000 07FF | 110xxxxx 10xxxxxx
* 0000 0800-0000 FFFF | 1110xxxx 10xxxxxx 10xxxxxx
* 0001 0000-0010 FFFF | 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
*/
while (*bytes) {
long code;

if ((bytes[0] & 0x80) == 0x00) {
/* Regular ASCII */
if (!valid_ascii_name_char(bytes[0]))
return false;
bytes += 1;
continue;

} else if ((bytes[0] & 0xe0) == 0xc0) {
/* 110xxxxx 10xxxxxx */
if ((bytes[1] & 0xc0) != 0x80) {
log_error("Invalid UTF-8: %02hhX %02hhX", bytes[0], bytes[1]);
return false;
}
code = ((long)(bytes[0] & 0x1f) << 6) |
((long)(bytes[1] & 0x3f) << 0);
bytes += 2;
} else if ((bytes[0] & 0xf0) == 0xe0) {
/* 1110xxxx 10xxxxxx 10xxxxxx */
if (((bytes[1] & 0xc0) != 0x80) ||
((bytes[2] & 0xc0) != 0x80)) {
log_error("Invalid UTF-8: %02hhX %02hhX %02hhX",
bytes[0], bytes[1], bytes[2]);
return false;
}
code = ((long)(bytes[0] & 0x0f) << 12) |
((long)(bytes[1] & 0x3f) << 6) |
((long)(bytes[2] & 0x3f) << 0);
bytes += 3;
} else if ((bytes[0] & 0xf8) == 0xf0 && (bytes[0] <= 0xf4)) {
/* 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx */
if (((bytes[1] & 0xc0) != 0x80) ||
((bytes[2] & 0xc0) != 0x80) ||
((bytes[3] & 0xc0) != 0x80)) {
log_error("Invalid UTF-8: %02hhX %02hhX %02hhX %02hhX",
bytes[0], bytes[1], bytes[2], bytes[3]);
return false;
}
code = ((long)(bytes[0] & 0x07) << 18) |
((long)(bytes[1] & 0x3f) << 12) |
((long)(bytes[2] & 0x3f) << 6) |
((long)(bytes[3] & 0x3f) << 0);
bytes += 4;
} else {
log_error("Invalid UTF-8: %02hhX", bytes[0]);
return false;
}

/*
* If we got here we have a valid UTF-8 character. Check it.
*/
if (!valid_utf8_name_char(code))
return false;
}

return true;
}

static void login_start(struct connection *conn)
{
struct iscsi_login_req_hdr *req = (struct iscsi_login_req_hdr *)&conn->req.bhs;
Expand All @@ -512,6 +798,11 @@ static void login_start(struct connection *conn)
return;
}

if (!name_chars_are_valid(name)) {
login_rsp_ini_err(conn, ISCSI_STATUS_INIT_ERR);
return;
}

conn->initiator = strdup(name);
if (conn->initiator == NULL) {
log_error("Unable to duplicate initiator's name %s", name);
Expand Down

0 comments on commit c59e33d

Please sign in to comment.