与内存打交道时的错误 - mremap_chunk：断言 [英] Error when dealing with memory - mremap_chunk: Assertion
问题描述
这似乎是我的previous职位，但这里的问题是不同的。
It seems like my previous post but issue here is different ..
这是问题的C结构 -
This is the C structure for problem -
typedef struct ip_esp_private { /* keep track of things privately */
u_int32_t type;
u_int32_t ivlen;
u_int32_t icvlen;
u_int32_t keylen; /* length of "Encryption key */
u_int32_t akeylen; /*length of authn key */
u_int32_t key[0]; /* encryption key and authentication key both */
} esp_private;
中提供的值来构建在运行时内容如下： -
The values are provided to structure contents at run time as follows -
case 'k': /* Key */
length = stringargument(arg, &temp);
priv->keylen = length;
priv = (esp_private *)realloc(priv,
sizeof(esp_private)+/*length*/priv->keylen);
/*This one is edited */
// if(priv->akeylen)
// memmove(&priv->key[priv->keylen],
// &priv->key[0],priv->akeylen);
/*These three are commented*/
memcpy(&priv->key[0], temp, priv->keylen);
pack->private = priv;
pack->modified |= ESP_MOD_KEY;
break;
case 'K': /* Authentication Key */
length = stringargument(arg, &temp);
priv->akeylen = length; // marked line(explained below)
priv = (esp_private *)realloc(priv,
sizeof(esp_private)+/*length*/priv->keylen+priv->akeylen);
/*this one edited too */
memcpy(&priv->key[priv->keylen/sizeof(u_int32_t)],
temp,priv->akeylen);
pack->private = priv;
pack->modified |= ESP_MOD_KEY;
现在有一种使用认证密钥的值的函数。
Now there is a function which uses the value of authentication key.
函数的相关部分是 -
The relevant part of the function is -
if (!epriv->akeylen) {
key = &fakekey;
keylen = 1;
} else {
key = (u_int8_t *)malloc(epriv->akeylen);
memcpy(key,&epriv->key[epriv->keylen/sizeof(u_int32_t)]
,epriv->akeylen);
现在，当我试图运行下面的程序，收到此错误，对此，我也没办法。
Now when I tried to run the following program , getting this error about which I have no idea.
sendip: malloc.c:3574: mremap_chunk: Assertion `((size + offset)
& (mp_.pagesize-1)) == 0' failed.
我想可能是有在功能部分的错误，但它到底是什么我不知道，
因为当我评论标记线（上述）的 akeylen 为空
所以服用了 fakekey 值和程序运行正常。
I think may be there is a error in function part but what exactly it is I am not sure,
because when I comment the marked line (mentioned above) the akeylen is null
so taking that fakekey value and program runs fine.
编辑1：
我已经编辑了code。在三个地方（也编辑在上面code）。
I have edited the code at three places (also edited in the above code ).
现在节目的作品，但出现不一致的输出。
Now program works but an inconsistent output occurs.
输入：
Encryption key - qwerty
Authentication key - abcdef
输出：
Encryption key - qwerab
Authentication key - abcdef
的情况更加清晰了。
The situation is more clear now .
这意味着现在的问题是肯定存在的的realloc 语句。
The problem it means is surely there at realloc statements .
请在此建议。
起初我添加长度在两个的realloc 语句，但现在我改成了 priv-＆GT; KEYLEN 在第一地方和 priv-＆GT; KEYLEN + priv-＆GT; akeylen 在SECONE地方。
Initially I added length at both realloc statements but now I changed it to priv->keylen at first place and priv->keylen+priv->akeylen at secone place.
但仍有一些需要改进
这是为什么???覆盖
推荐答案
由于键[0]结构黑客似乎包含空间这两个键，你需要为分配内存，太多。在这两种情况下（'K'和'K'）
Since the key[0] struct hack appears to contain space for both keys, you'll need to allocate memory for both, too. In both cases ('k' and 'K' )
priv = realloc(priv, sizeof *priv +priv->keylen+priv->akeylen);
在串联的两个键，它是最容易投的u_int32_t钥匙插入字符指针，做算术上一句：
When concatenating the two keys, it is easiest to cast the u_int32_t key into a character pointer and do arithmatic on that one:
memcpy ( priv->key, source1, sizeofsource1);
/* and */
memcpy ( ((char*) priv->key) +priv->keylen, source2, sizeofsource2);
[和用于的memmove类似（）]
在程序中强制转换的其余部分可以被删除。
[and similar for the memmove()] The rest of the casts in your program can be removed.
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