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86bf43c7c2
This is an update for 460c03f3f3 ("iplink: double the buffer size also in
iplink_get()"). After update, we will not need to double the buffer size
every time when VFs number increased.
With call like rtnl_talk(&rth, &req.n, NULL, 0), we can simply remove the
length parameter.
With call like rtnl_talk(&rth, nlh, nlh, sizeof(req), I add a new variable
answer to avoid overwrite data in nlh, because it may has more info after
nlh. also this will avoid nlh buffer not enough issue.
We need to free answer after using.
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Phil Sutter <phil@nwl.cc>
86 lines
1.8 KiB
C
86 lines
1.8 KiB
C
/*
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* libgenl.c GENL library
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <linux/genetlink.h>
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#include "libgenl.h"
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static int genl_parse_getfamily(struct nlmsghdr *nlh)
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{
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struct rtattr *tb[CTRL_ATTR_MAX + 1];
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struct genlmsghdr *ghdr = NLMSG_DATA(nlh);
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int len = nlh->nlmsg_len;
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struct rtattr *attrs;
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if (nlh->nlmsg_type != GENL_ID_CTRL) {
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fprintf(stderr, "Not a controller message, nlmsg_len=%d "
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"nlmsg_type=0x%x\n", nlh->nlmsg_len, nlh->nlmsg_type);
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return -1;
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}
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len -= NLMSG_LENGTH(GENL_HDRLEN);
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if (len < 0) {
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fprintf(stderr, "wrong controller message len %d\n", len);
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return -1;
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}
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if (ghdr->cmd != CTRL_CMD_NEWFAMILY) {
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fprintf(stderr, "Unknown controller command %d\n", ghdr->cmd);
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return -1;
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}
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attrs = (struct rtattr *) ((char *) ghdr + GENL_HDRLEN);
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parse_rtattr(tb, CTRL_ATTR_MAX, attrs, len);
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if (tb[CTRL_ATTR_FAMILY_ID] == NULL) {
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fprintf(stderr, "Missing family id TLV\n");
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return -1;
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}
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return rta_getattr_u16(tb[CTRL_ATTR_FAMILY_ID]);
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}
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int genl_resolve_family(struct rtnl_handle *grth, const char *family)
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{
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GENL_REQUEST(req, 1024, GENL_ID_CTRL, 0, 0, CTRL_CMD_GETFAMILY,
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NLM_F_REQUEST);
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struct nlmsghdr *answer;
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int fnum;
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addattr_l(&req.n, sizeof(req), CTRL_ATTR_FAMILY_NAME,
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family, strlen(family) + 1);
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if (rtnl_talk(grth, &req.n, &answer) < 0) {
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fprintf(stderr, "Error talking to the kernel\n");
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return -2;
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}
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fnum = genl_parse_getfamily(answer);
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free(answer);
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return fnum;
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}
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int genl_init_handle(struct rtnl_handle *grth, const char *family,
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int *genl_family)
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{
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if (*genl_family >= 0)
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return 0;
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if (rtnl_open_byproto(grth, 0, NETLINK_GENERIC) < 0) {
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fprintf(stderr, "Cannot open generic netlink socket\n");
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return -1;
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}
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*genl_family = genl_resolve_family(grth, family);
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if (*genl_family < 0)
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return -1;
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return 0;
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}
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