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-rw-r--r--src/libsystemd-network/dhcp6-option.c18
-rw-r--r--src/resolve/resolved-dns-packet.c18
-rw-r--r--src/resolve/resolved-manager.c2
-rw-r--r--src/shared/dns-domain.c88
-rw-r--r--src/shared/dns-domain.h5
-rw-r--r--src/test/test-dns-domain.c2
6 files changed, 84 insertions, 49 deletions
diff --git a/src/libsystemd-network/dhcp6-option.c b/src/libsystemd-network/dhcp6-option.c
index 62023a9e49..850212aea1 100644
--- a/src/libsystemd-network/dhcp6-option.c
+++ b/src/libsystemd-network/dhcp6-option.c
@@ -360,7 +360,6 @@ int dhcp6_option_parse_domainname(const uint8_t *optval, uint16_t optlen, char *
/* End of name */
break;
else if (c <= 63) {
- _cleanup_free_ char *t = NULL;
const char *label;
/* Literal label */
@@ -369,21 +368,20 @@ int dhcp6_option_parse_domainname(const uint8_t *optval, uint16_t optlen, char *
if (pos > optlen)
return -EMSGSIZE;
- r = dns_label_escape(label, c, &t);
- if (r < 0)
- goto fail;
-
- if (!GREEDY_REALLOC0(ret, allocated, n + !first + strlen(t) + 1)) {
+ if (!GREEDY_REALLOC(ret, allocated, n + !first + DNS_LABEL_ESCAPED_MAX)) {
r = -ENOMEM;
goto fail;
}
- if (!first)
- ret[n++] = '.';
- else
+ if (first)
first = false;
+ else
+ ret[n++] = '.';
+
+ r = dns_label_escape(label, c, ret + n, DNS_LABEL_ESCAPED_MAX);
+ if (r < 0)
+ goto fail;
- memcpy(ret + n, t, r);
n += r;
continue;
} else {
diff --git a/src/resolve/resolved-dns-packet.c b/src/resolve/resolved-dns-packet.c
index 472486777c..aeff3138d7 100644
--- a/src/resolve/resolved-dns-packet.c
+++ b/src/resolve/resolved-dns-packet.c
@@ -1145,7 +1145,6 @@ int dns_packet_read_name(
/* End of name */
break;
else if (c <= 63) {
- _cleanup_free_ char *t = NULL;
const char *label;
/* Literal label */
@@ -1153,21 +1152,20 @@ int dns_packet_read_name(
if (r < 0)
goto fail;
- r = dns_label_escape(label, c, &t);
- if (r < 0)
- goto fail;
-
- if (!GREEDY_REALLOC(ret, allocated, n + !first + strlen(t) + 1)) {
+ if (!GREEDY_REALLOC(ret, allocated, n + !first + DNS_LABEL_ESCAPED_MAX)) {
r = -ENOMEM;
goto fail;
}
- if (!first)
- ret[n++] = '.';
- else
+ if (first)
first = false;
+ else
+ ret[n++] = '.';
+
+ r = dns_label_escape(label, c, ret + n, DNS_LABEL_ESCAPED_MAX);
+ if (r < 0)
+ goto fail;
- memcpy(ret + n, t, r);
n += r;
continue;
} else if (allow_compression && (c & 0xc0) == 0xc0) {
diff --git a/src/resolve/resolved-manager.c b/src/resolve/resolved-manager.c
index 64703ab713..f1f454c786 100644
--- a/src/resolve/resolved-manager.c
+++ b/src/resolve/resolved-manager.c
@@ -351,7 +351,7 @@ static int determine_hostname(char **llmnr_hostname, char **mdns_hostname) {
return -EINVAL;
}
- r = dns_label_escape(label, r, &n);
+ r = dns_label_escape_new(label, r, &n);
if (r < 0)
return log_error_errno(r, "Failed to escape host name: %m");
diff --git a/src/shared/dns-domain.c b/src/shared/dns-domain.c
index 5a9b091ac4..4cf6355b71 100644
--- a/src/shared/dns-domain.c
+++ b/src/shared/dns-domain.c
@@ -182,30 +182,31 @@ int dns_label_unescape_suffix(const char *name, const char **label_terminal, cha
return r;
}
-int dns_label_escape(const char *p, size_t l, char **ret) {
- _cleanup_free_ char *s = NULL;
+int dns_label_escape(const char *p, size_t l, char *dest, size_t sz) {
char *q;
- int r;
-
- assert(p);
- assert(ret);
if (l > DNS_LABEL_MAX)
return -EINVAL;
+ if (sz < 1)
+ return -ENOSPC;
- s = malloc(l * 4 + 1);
- if (!s)
- return -ENOMEM;
+ assert(p);
+ assert(dest);
- q = s;
+ q = dest;
while (l > 0) {
if (*p == '.' || *p == '\\') {
+ if (sz < 3)
+ return -ENOSPC;
+
/* Dot or backslash */
*(q++) = '\\';
*(q++) = *p;
+ sz -= 2;
+
} else if (*p == '_' ||
*p == '-' ||
(*p >= '0' && *p <= '9') ||
@@ -213,15 +214,27 @@ int dns_label_escape(const char *p, size_t l, char **ret) {
(*p >= 'A' && *p <= 'Z')) {
/* Proper character */
+
+ if (sz < 2)
+ return -ENOSPC;
+
*(q++) = *p;
+ sz -= 1;
+
} else if ((uint8_t) *p >= (uint8_t) ' ' && *p != 127) {
/* Everything else */
+
+ if (sz < 5)
+ return -ENOSPC;
+
*(q++) = '\\';
*(q++) = '0' + (char) ((uint8_t) *p / 100);
*(q++) = '0' + (char) (((uint8_t) *p / 10) % 10);
*(q++) = '0' + (char) ((uint8_t) *p % 10);
+ sz -= 4;
+
} else
return -EINVAL;
@@ -230,8 +243,28 @@ int dns_label_escape(const char *p, size_t l, char **ret) {
}
*q = 0;
+ return (int) (q - dest);
+}
+
+int dns_label_escape_new(const char *p, size_t l, char **ret) {
+ _cleanup_free_ char *s = NULL;
+ int r;
+
+ assert(p);
+ assert(ret);
+
+ if (l > DNS_LABEL_MAX)
+ return -EINVAL;
+
+ s = new(char, DNS_LABEL_ESCAPED_MAX);
+ if (!s)
+ return -ENOMEM;
+
+ r = dns_label_escape(p, l, s, DNS_LABEL_ESCAPED_MAX);
+ if (r < 0)
+ return r;
+
*ret = s;
- r = q - s;
s = NULL;
return r;
@@ -351,28 +384,32 @@ int dns_name_concat(const char *a, const char *b, char **_ret) {
if (k > 0)
r = k;
- r = dns_label_escape(label, r, &t);
- if (r < 0)
- return r;
-
if (_ret) {
- if (!GREEDY_REALLOC(ret, allocated, n + !first + strlen(t) + 1))
+ if (!GREEDY_REALLOC(ret, allocated, n + !first + DNS_LABEL_ESCAPED_MAX))
return -ENOMEM;
+ r = dns_label_escape(label, r, ret + n + !first, DNS_LABEL_ESCAPED_MAX);
+ if (r < 0)
+ return r;
+
if (!first)
- ret[n++] = '.';
- else
- first = false;
+ ret[n] = '.';
+ } else {
+ char escaped[DNS_LABEL_ESCAPED_MAX];
- memcpy(ret + n, t, r);
+ r = dns_label_escape(label, r, escaped, sizeof(escaped));
+ if (r < 0)
+ return r;
}
+ if (!first)
+ n++;
+ else
+ first = false;
+
n += r;
}
- if (n > DNS_NAME_MAX)
- return -EINVAL;
-
if (_ret) {
if (!GREEDY_REALLOC(ret, allocated, n + 1))
return -ENOMEM;
@@ -892,7 +929,8 @@ bool dns_service_name_is_valid(const char *name) {
}
int dns_service_join(const char *name, const char *type, const char *domain, char **ret) {
- _cleanup_free_ char *escaped = NULL, *n = NULL;
+ char escaped[DNS_LABEL_ESCAPED_MAX];
+ _cleanup_free_ char *n = NULL;
int r;
assert(type);
@@ -908,7 +946,7 @@ int dns_service_join(const char *name, const char *type, const char *domain, cha
if (!dns_service_name_is_valid(name))
return -EINVAL;
- r = dns_label_escape(name, strlen(name), &escaped);
+ r = dns_label_escape(name, strlen(name), escaped, sizeof(escaped));
if (r < 0)
return r;
diff --git a/src/shared/dns-domain.h b/src/shared/dns-domain.h
index 2f557d618e..99c72574db 100644
--- a/src/shared/dns-domain.h
+++ b/src/shared/dns-domain.h
@@ -26,11 +26,12 @@
#include "in-addr-util.h"
#define DNS_LABEL_MAX 63
-#define DNS_NAME_MAX 255
+#define DNS_LABEL_ESCAPED_MAX (DNS_LABEL_MAX*4+1)
int dns_label_unescape(const char **name, char *dest, size_t sz);
int dns_label_unescape_suffix(const char *name, const char **label_end, char *dest, size_t sz);
-int dns_label_escape(const char *p, size_t l, char **ret);
+int dns_label_escape(const char *p, size_t l, char *dest, size_t sz);
+int dns_label_escape_new(const char *p, size_t l, char **ret);
int dns_label_apply_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max);
int dns_label_undo_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max);
diff --git a/src/test/test-dns-domain.c b/src/test/test-dns-domain.c
index df34b72ab6..f010e4e19a 100644
--- a/src/test/test-dns-domain.c
+++ b/src/test/test-dns-domain.c
@@ -126,7 +126,7 @@ static void test_dns_label_escape_one(const char *what, size_t l, const char *ex
_cleanup_free_ char *t = NULL;
int r;
- r = dns_label_escape(what, l, &t);
+ r = dns_label_escape_new(what, l, &t);
assert_se(r == ret);
if (r < 0)
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-14 08:56:23 +0000